1
|
Kaushik V, Dąbrowski M, Gessa L, Kumar N, Fernandes H. Two-photon excitation fluorescence in ophthalmology: safety and improved imaging for functional diagnostics. Front Med (Lausanne) 2024; 10:1293640. [PMID: 38235268 PMCID: PMC10791900 DOI: 10.3389/fmed.2023.1293640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 12/11/2023] [Indexed: 01/19/2024] Open
Abstract
Two-photon excitation fluorescence (TPEF) is emerging as a powerful imaging technique with superior penetration power in scattering media, allowing for functional imaging of biological tissues at a subcellular level. TPEF is commonly used in cancer diagnostics, as it enables the direct observation of metabolism within living cells. The technique is now widely used in various medical fields, including ophthalmology. The eye is a complex and delicate organ with multiple layers of different cell types and tissues. Although this structure is ideal for visual perception, it generates aberrations in TPEF eye imaging. However, adaptive optics can now compensate for these aberrations, allowing for improved imaging of the eyes of animal models for human diseases. The eye is naturally built to filter out harmful wavelengths, but these wavelengths can be mimicked and thereby utilized in diagnostics via two-photon (2Ph) excitation. Recent advances in laser-source manufacturing have made it possible to minimize the exposure of in vivo measurements within safety, while achieving sufficient signals to detect for functional images, making TPEF a viable option for human application. This review explores recent advances in wavefront-distortion correction in animal models and the safety of use of TPEF on human subjects, both of which make TPEF a potentially powerful tool for ophthalmological diagnostics.
Collapse
Affiliation(s)
- Vineeta Kaushik
- Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Michał Dąbrowski
- Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
- International Centre for Translational Eye Research, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Luca Gessa
- International Centre for Translational Eye Research, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Nelam Kumar
- International Centre for Translational Eye Research, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - Humberto Fernandes
- International Centre for Translational Eye Research, Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| |
Collapse
|
2
|
Chang S, Yang J, Novoseltseva A, Abdelhakeem A, Hyman M, Fu X, Li C, Chen S, Augustinack JC, Magnain C, Fischl B, Mckee AC, Boas DA, Chen IA, Wang H. Multi-Scale Label-Free Human Brain Imaging with Integrated Serial Sectioning Polarization Sensitive Optical Coherence Tomography and Two-Photon Microscopy. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2303381. [PMID: 37882348 PMCID: PMC10724383 DOI: 10.1002/advs.202303381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 08/29/2023] [Indexed: 10/27/2023]
Abstract
The study of aging and neurodegenerative processes in the human brain requires a comprehensive understanding of cytoarchitectonic, myeloarchitectonic, and vascular structures. Recent computational advances have enabled volumetric reconstruction of the human brain using thousands of stained slices, however, tissue distortions and loss resulting from standard histological processing have hindered deformation-free reconstruction. Here, the authors describe an integrated serial sectioning polarization-sensitive optical coherence tomography (PSOCT) and two photon microscopy (2PM) system to provide label-free multi-contrast imaging of intact brain structures, including scattering, birefringence, and autofluorescence of human brain tissue. The authors demonstrate high-throughput reconstruction of 4 × 4 × 2cm3 sample blocks and simple registration between PSOCT and 2PM images that enable comprehensive analysis of myelin content, vascular structure, and cellular information. The high-resolution 2PM images provide microscopic validation and enrichment of the cellular information provided by the PSOCT optical properties on the same sample, revealing the densely packed fibers, capillaries, and lipofuscin-filled cell bodies in the cortex and white matter. It is shown that the imaging system enables quantitative characterization of various pathological features in aging process, including myelin degradation, lipofuscin accumulation, and microvascular changes, which opens up numerous opportunities in the study of neurodegenerative diseases in the future.
Collapse
Affiliation(s)
- Shuaibin Chang
- Department of Electrical and Computer EngineeringBoston University8 St Mary's StBoston02215USA
| | - Jiarui Yang
- Department of Biomedical EngineeringBoston University44 Cummington MallBoston02215USA
| | - Anna Novoseltseva
- Department of Biomedical EngineeringBoston University44 Cummington MallBoston02215USA
| | - Ayman Abdelhakeem
- Department of Electrical and Computer EngineeringBoston University8 St Mary's StBoston02215USA
| | - Mackenzie Hyman
- Department of Biomedical EngineeringBoston University44 Cummington MallBoston02215USA
| | - Xinlei Fu
- Department of Mechanical EngineeringThe Chinese University of Hong KongHong Kong999077China
| | - Chenglin Li
- Department of Mechanical EngineeringThe Chinese University of Hong KongHong Kong999077China
| | - Shih‐Chi Chen
- Department of Mechanical EngineeringThe Chinese University of Hong KongHong Kong999077China
| | - Jean C. Augustinack
- Department of RadiologyMassachusetts General HospitalA.A. Martinos Center for Biomedical Imaging13th StreetBoston02129USA
| | - Caroline Magnain
- Department of RadiologyMassachusetts General HospitalA.A. Martinos Center for Biomedical Imaging13th StreetBoston02129USA
| | - Bruce Fischl
- Department of RadiologyMassachusetts General HospitalA.A. Martinos Center for Biomedical Imaging13th StreetBoston02129USA
| | - Ann C. Mckee
- VA Boston Healthcare SystemU.S. Department of Veteran AffairsBoston02132USA
- Boston University Chobanian and Avedisian School of MedicineBoston University Alzheimer's Disease Research Center and CTE CenterBoston02118USA
- Department of NeurologyBoston University Chobanian and Avedisian School of MedicineBoston02118USA
- Department of Pathology and Laboratory MedicineBoston University Chobanian and Avedisian School of MedicineBoston02118USA
- VA Bedford Healthcare SystemU.S. Department of Veteran AffairsBedfordMA01730‐1114USA
| | - David A. Boas
- Department of Electrical and Computer EngineeringBoston University8 St Mary's StBoston02215USA
- Department of Biomedical EngineeringBoston University44 Cummington MallBoston02215USA
| | - Ichun Anderson Chen
- Department of Biomedical EngineeringBoston University44 Cummington MallBoston02215USA
| | - Hui Wang
- Department of RadiologyMassachusetts General HospitalA.A. Martinos Center for Biomedical Imaging13th StreetBoston02129USA
| |
Collapse
|
3
|
Wang X, Elbahrawi RT, Abdukadir AM, Ali ZM, Chan V, Corridon PR. A proposed model of xeno-keratoplasty using 3D printing and decellularization. Front Pharmacol 2023; 14:1193606. [PMID: 37799970 PMCID: PMC10548234 DOI: 10.3389/fphar.2023.1193606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 09/06/2023] [Indexed: 10/07/2023] Open
Abstract
Corneal opacity is a leading cause of vision impairment and suffering worldwide. Transplantation can effectively restore vision and reduce chronic discomfort. However, there is a considerable shortage of viable corneal graft tissues. Tissue engineering may address this issue by advancing xeno-keratoplasty as a viable alternative to conventional keratoplasty. In particular, livestock decellularization strategies offer the potential to generate bioartificial ocular prosthetics in sufficient supply to match existing and projected needs. To this end, we have examined the best practices and characterizations that have supported the current state-of-the-art driving preclinical and clinical applications. Identifying the challenges that delimit activities to supplement the donor corneal pool derived from acellular scaffolds allowed us to hypothesize a model for keratoprosthesis applications derived from livestock combining 3D printing and decellularization.
Collapse
Affiliation(s)
- Xinyu Wang
- Biomedical Engineering and Healthcare Engineering Innovation Center, Khalifa University, Abu Dhabi, United Arab Emirates
- Department of Immunology and Physiology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi, United Arab Emirates
| | - Rawdah Taha Elbahrawi
- Department of Immunology and Physiology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi, United Arab Emirates
| | - Azhar Mohamud Abdukadir
- Department of Immunology and Physiology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi, United Arab Emirates
| | - Zehara Mohammed Ali
- Department of Immunology and Physiology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi, United Arab Emirates
| | - Vincent Chan
- Biomedical Engineering and Healthcare Engineering Innovation Center, Khalifa University, Abu Dhabi, United Arab Emirates
| | - Peter R. Corridon
- Biomedical Engineering and Healthcare Engineering Innovation Center, Khalifa University, Abu Dhabi, United Arab Emirates
- Department of Immunology and Physiology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi, United Arab Emirates
- Center for Biotechnology, Khalifa University, Abu Dhabi, United Arab Emirates
- Hleathcare, Engineering and Innovation Center, Khalifa University, Abu Dhabi, United Arab Emirates
| |
Collapse
|
4
|
Chang S, Yang J, Novoseltseva A, Fu X, Li C, Chen SC, Augustinack JC, Magnain C, Fischl B, Mckee AC, Boas DA, Chen IA, Wang H. Multi-Scale Label-free Human Brain Imaging with Integrated Serial Sectioning Polarization Sensitive Optical Coherence Tomography and Two-Photon Microscopy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.22.541785. [PMID: 37293092 PMCID: PMC10245911 DOI: 10.1101/2023.05.22.541785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The study of neurodegenerative processes in the human brain requires a comprehensive understanding of cytoarchitectonic, myeloarchitectonic, and vascular structures. Recent computational advances have enabled volumetric reconstruction of the human brain using thousands of stained slices, however, tissue distortions and loss resulting from standard histological processing have hindered deformation-free reconstruction of the human brain. The development of a multi-scale and volumetric human brain imaging technique that can measure intact brain structure would be a major technical advance. Here, we describe the development of integrated serial sectioning Polarization Sensitive Optical Coherence Tomography (PSOCT) and Two Photon Microscopy (2PM) to provide label-free multi-contrast imaging, including scattering, birefringence and autofluorescence of human brain tissue. We demonstrate that high-throughput reconstruction of 4×4×2cm3 sample blocks and simple registration of PSOCT and 2PM images enable comprehensive analysis of myelin content, vascular structure, and cellular information. We show that 2μm in-plane resolution 2PM images provide microscopic validation and enrichment of the cellular information provided by the PSOCT optical property maps on the same sample, revealing the sophisticated capillary networks and lipofuscin filled cell bodies across the cortical layers. Our method is applicable to the study of a variety of pathological processes, including demyelination, cell loss, and microvascular changes in neurodegenerative diseases such as Alzheimer's disease (AD) and Chronic Traumatic Encephalopathy (CTE).
Collapse
Affiliation(s)
- Shuaibin Chang
- Department of Electrical and Computer Engineering, Boston University, 8 St Mary’s St, Boston 02215, USA
| | - Jiarui Yang
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston 02215, USA
| | - Anna Novoseltseva
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston 02215, USA
| | - Xinlei Fu
- The Chinese University of Hong Kong, Department of Mechanical Engineering, Hong Kong Special Administrative Region, China
| | - Chenglin Li
- The Chinese University of Hong Kong, Department of Mechanical Engineering, Hong Kong Special Administrative Region, China
| | - Shih-Chi Chen
- The Chinese University of Hong Kong, Department of Mechanical Engineering, Hong Kong Special Administrative Region, China
| | - Jean C. Augustinack
- Department of Radiology, Massachusetts General Hospital, A.A. Martinos Center for Biomedical Imaging, 13th Street, Boston 02129, USA
| | - Caroline Magnain
- Department of Radiology, Massachusetts General Hospital, A.A. Martinos Center for Biomedical Imaging, 13th Street, Boston 02129, USA
| | - Bruce Fischl
- Department of Radiology, Massachusetts General Hospital, A.A. Martinos Center for Biomedical Imaging, 13th Street, Boston 02129, USA
| | - Ann C. Mckee
- VA Boston Healthcare System, U.S. Department of Veteran Affairs
- Boston University Chobanian and Avedisian School of Medicine, Boston University Alzheimer’s Disease Research Center and CTE Center
- Department of Neurology, Boston University Chobanian and Avedisian School of Medicine
- Department of Pathology and Laboratory Medicine, Boston University Chobanian and Avedisian School of Medicine
- VA Bedford Healthcare System, U.S. Department of Veteran Affairs, Bedford, MA, USA
| | - David A. Boas
- Department of Electrical and Computer Engineering, Boston University, 8 St Mary’s St, Boston 02215, USA
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston 02215, USA
| | - Ichun Anderson Chen
- Department of Biomedical Engineering, Boston University, 44 Cummington Mall, Boston 02215, USA
| | - Hui Wang
- Department of Radiology, Massachusetts General Hospital, A.A. Martinos Center for Biomedical Imaging, 13th Street, Boston 02129, USA
| |
Collapse
|
5
|
Torun SG, Munoz PDM, Crielaard H, Verhagen HJM, Kremers GJ, van der Steen AFW, Akyildiz AC. Local Characterization of Collagen Architecture and Mechanical Failure Properties of Fibrous Plaque Tissue of Atherosclerotic Human Carotid Arteries. Acta Biomater 2023; 164:293-302. [PMID: 37086826 DOI: 10.1016/j.actbio.2023.04.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 04/05/2023] [Accepted: 04/13/2023] [Indexed: 04/24/2023]
Abstract
Atherosclerotic plaque rupture in carotid arteries is a major cause of cerebrovascular events. Plaque rupture is the mechanical failure of the heterogeneous fibrous plaque tissue. Local characterization of the tissue's failure properties and the collagen architecture are of great importance to have insights in plaque rupture for clinical event prevention. Previous studies were limited to average rupture properties and global structural characterization, and did not provide the necessary local information. In this study, we assessed the local collagen architecture and failure properties of fibrous plaque tissue, by analyzing 30 tissue strips from 18 carotid plaques. Our study framework entailed second harmonic generation imaging for local collagen orientation and dispersion, and uniaxial tensile testing and digital image correlation for local tissue mechanics. The results showed that 87% of the imaged locations had collagen orientation close to the circumferential direction (0°) of the artery, and substantial dispersion locally. All regions combined, median [Q1:Q3] of the predominant angle measurements was -2° [-16°:16°]. The stretch ratio measurements clearly demonstrated a nonuniform stretch ratio distribution in the tissue under uniaxial loading. The rupture initiation regions had significantly higher stretch ratios (1.26 [1.15-1.40]) than the tissue average stretch ratio (1.11 [1.10-1.16]). No significant difference in collagen direction and dispersion was identified between the rupture regions and the rest of the tissue. The presented study forms an initial step towards gaining better insights into the characterization of local structural and mechanical fingerprints of fibrous plaque tissue in order to aid improved assessment of plaque rupture risk. STATEMENT OF SIGNIFICANCE: Plaque rupture risk assessment, critical to prevent cardiovascular events, requires knowledge on local failure properties and structure of collagenous plaque tissue. Our current knowledge is unfortunately limited to tissue's overall ultimate failure properties with scarce information on collagen architecture. In this study, local failure properties and collagen architecture of fibrous plaque tissue were obtained. We found predominant circumferential alignment of collagen fibers with substantial local dispersion. The tissue showed nonuniform stretch distribution under uniaxial tensile loading, with high stretches at rupture spots. This study highlights the significance of local mechanical and structural assessment for better insights into plaque rupture and the potential use of local stretches as risk marker for plaque rupture for patient-specific clinical applications.
Collapse
Affiliation(s)
- Su Guvenir Torun
- Department of Biomedical Engineering, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Pablo de Miguel Munoz
- Department of Biomedical Engineering, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Biomechanical Engineering, Delft University of Technology, Delft, The Netherlands
| | - Hanneke Crielaard
- Department of Biomedical Engineering, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Hence J M Verhagen
- Department of Vascular Surgery, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Gert-Jan Kremers
- Erasmus Optical Imaging Center, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Antonius F W van der Steen
- Department of Biomedical Engineering, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Biomechanical Engineering, Delft University of Technology, Delft, The Netherlands
| | - Ali C Akyildiz
- Department of Biomedical Engineering, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Biomechanical Engineering, Delft University of Technology, Delft, The Netherlands.
| |
Collapse
|
6
|
Ghezzi M, Ferraboschi I, Fantini A, Pescina S, Padula C, Santi P, Sissa C, Nicoli S. Hyaluronic acid - PVA films for the simultaneous delivery of dexamethasone and levofloxacin to ocular tissues. Int J Pharm 2023; 638:122911. [PMID: 37028574 DOI: 10.1016/j.ijpharm.2023.122911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/27/2023] [Accepted: 03/29/2023] [Indexed: 04/08/2023]
Abstract
Ocular drug delivery is challenging due to the poor drug penetration across ocular barriers and short retention time of the formulation at the application site. Films, applied as inserts or implants, can be used to increase residence time while controlling drug release. In this work, hydrophilic films made of hyaluronic acid and two kinds of PVA were loaded with dexamethasone (included as hydroxypropylcyclodextrin complex) and levofloxacin. This association represents one of the main treatments for the post cataract surgery management, and it is also promising for eye infections whith pain and inflammation. Films were characterized in terms of swelling and drug release and were then applied to porcine eye bulbs and isolated ocular tissues. Film swelling leads to the formation of either a gel (3D swelling) or a larger film (2D swelling) depending on the type of PVA used. Films, prepared in an easy and scalable method, demonstrated high loading capacity, controlled drug release and the capability to deliver dexamethasone and levofloxacin to the cornea and across the sclera, to potentially target also the posterior eye segment. Overall, this device can be considered a multipurpose delivery platform intended for the concomitant release of lipophilic and hydrophilic drugs.
Collapse
|
7
|
Aghigh A, Bancelin S, Rivard M, Pinsard M, Ibrahim H, Légaré F. Second harmonic generation microscopy: a powerful tool for bio-imaging. Biophys Rev 2023; 15:43-70. [PMID: 36909955 PMCID: PMC9995455 DOI: 10.1007/s12551-022-01041-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 12/21/2022] [Indexed: 01/20/2023] Open
Abstract
Second harmonic generation (SHG) microscopy is an important optical imaging technique in a variety of applications. This article describes the history and physical principles of SHG microscopy and its more advanced variants, as well as their strengths and weaknesses in biomedical applications. It also provides an overview of SHG and advanced SHG imaging in neuroscience and microtubule imaging and how these methods can aid in understanding microtubule formation, structuration, and involvement in neuronal function. Finally, we offer a perspective on the future of these methods and how technological advancements can help make SHG microscopy a more widely adopted imaging technique.
Collapse
Affiliation(s)
- Arash Aghigh
- Centre Énergie Matériaux Télécommunications, Institut National de La Recherche Scientifique, Varennes, QC Canada
| | | | - Maxime Rivard
- National Research Council Canada, Boucherville, QC Canada
| | - Maxime Pinsard
- Institut National de Recherche en Sciences Et Technologies Pour L’environnement Et L’agriculture, Paris, France
| | - Heide Ibrahim
- Centre Énergie Matériaux Télécommunications, Institut National de La Recherche Scientifique, Varennes, QC Canada
| | - François Légaré
- Centre Énergie Matériaux Télécommunications, Institut National de La Recherche Scientifique, Varennes, QC Canada
| |
Collapse
|
8
|
Batista A, Guimarães P, Domingues JP, Quadrado MJ, Morgado AM. Two-Photon Imaging for Non-Invasive Corneal Examination. SENSORS (BASEL, SWITZERLAND) 2022; 22:9699. [PMID: 36560071 PMCID: PMC9783858 DOI: 10.3390/s22249699] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 12/02/2022] [Accepted: 12/04/2022] [Indexed: 06/17/2023]
Abstract
Two-photon imaging (TPI) microscopy, namely, two-photon excited fluorescence (TPEF), fluorescence lifetime imaging (FLIM), and second-harmonic generation (SHG) modalities, has emerged in the past years as a powerful tool for the examination of biological tissues. These modalities rely on different contrast mechanisms and are often used simultaneously to provide complementary information on morphology, metabolism, and structural properties of the imaged tissue. The cornea, being a transparent tissue, rich in collagen and with several cellular layers, is well-suited to be imaged by TPI microscopy. In this review, we discuss the physical principles behind TPI as well as its instrumentation. We also provide an overview of the current advances in TPI instrumentation and image analysis. We describe how TPI can be leveraged to retrieve unique information on the cornea and to complement the information provided by current clinical devices. The present state of corneal TPI is outlined. Finally, we discuss the obstacles that must be overcome and offer perspectives and outlooks to make clinical TPI of the human cornea a reality.
Collapse
Affiliation(s)
- Ana Batista
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, 3000-548 Coimbra, Portugal
- Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
- Department of Physics, Faculty of Science and Technology, University of Coimbra, 3004-516 Coimbra, Portugal
| | - Pedro Guimarães
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, 3000-548 Coimbra, Portugal
- Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
| | - José Paulo Domingues
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, 3000-548 Coimbra, Portugal
- Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
- Department of Physics, Faculty of Science and Technology, University of Coimbra, 3004-516 Coimbra, Portugal
| | - Maria João Quadrado
- Department of Ophthalmology, Centro Hospitalar e Universitário de Coimbra, 3004-561 Coimbra, Portugal
- Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
| | - António Miguel Morgado
- Coimbra Institute for Biomedical Imaging and Translational Research (CIBIT), University of Coimbra, 3000-548 Coimbra, Portugal
- Institute for Nuclear Sciences Applied to Health (ICNAS), University of Coimbra, 3000-548 Coimbra, Portugal
- Department of Physics, Faculty of Science and Technology, University of Coimbra, 3004-516 Coimbra, Portugal
| |
Collapse
|
9
|
Clark MG, Gonzalez GA, Zhang C. Pulse-Picking Multimodal Nonlinear Optical Microscopy. Anal Chem 2022; 94:15405-15414. [DOI: 10.1021/acs.analchem.2c03284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Matthew G. Clark
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana47907, United States
| | - Gil A. Gonzalez
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana47907, United States
| | - Chi Zhang
- Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana47907, United States
- Purdue Center for Cancer Research, 201 S University Street, West Lafayette, Indiana47907, United States
- Purdue Institute of Inflammation, Immunology, and Infectious Disease, 207 S Martin Jischke Drive, West Lafayette, Indiana47907, United States
| |
Collapse
|
10
|
Zeitoune AA, Bersanetti PA, Schor P, Erbes LA, Cesar CL, Adur J. Comparison of morphological changes of corneal collagen fibers treated with collagen crosslinking agents using second harmonic generation images. Int J Biol Macromol 2020; 165:346-353. [PMID: 32987082 DOI: 10.1016/j.ijbiomac.2020.09.147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 09/18/2020] [Accepted: 09/19/2020] [Indexed: 10/23/2022]
Abstract
Corneal cross-linking (CXL) is a common surgical procedure used to modify corneal biomechanics and stabilize keratoconus progression which is still under discussion. Its side effects, which are mostly related to anatomical unpredictability and stromal exposure, are the reason for the search for new CXL agents. In this work we have quantitatively evaluated the porcine corneal stroma architecture treated with collagen crosslinking agents such as riboflavin solutions and açai extract, using second harmonic generation microscopy. Aimed at evaluating the morphological changes in the corneal stroma after collagen crosslinking under a CXL chemical agent, a tubeness filter based Hessian matrix to obtain a 3D fiber characterization of the SHG images was applied. The results showed a curling effect and shortening of the collagen fibers treated with açai as compared to the control. They also showed a higher degree of clustering of the collagen fibers with larger empty spaces when compared to the other two groups. We believe that studies such as these presented in this paper are a good direct nondestructive and free labeling evaluation technique that allows the observation of morphologic features of corneas treated with new CXL agents.
Collapse
Affiliation(s)
- Angel A Zeitoune
- Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática (IBB), UNER, CONICET, Oro Verde, Entre Ríos, Argentina.
| | - Patrícia A Bersanetti
- Department of Biochemistry, Paulista School of Medicine, Federal University of São Paulo, São Paulo, Brazil
| | - Paulo Schor
- Department of Ophthalmology and Visual Sciences, Paulista School of Medicine, Federal University of São Paulo, São Paulo, Brazil
| | - Luciana A Erbes
- Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática (IBB), UNER, CONICET, Oro Verde, Entre Ríos, Argentina.
| | - Carlos L Cesar
- Department of Physics of Federal University of Ceara (UFC), Brazil; INFABiC - National Institute of Science and Technology on Photonics Applied to Cell Biology, Campinas, Brazil
| | - Javier Adur
- Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática (IBB), UNER, CONICET, Oro Verde, Entre Ríos, Argentina.
| |
Collapse
|
11
|
Seet LF, Chu SWL, Teng X, Toh LZ, Wong TT. Assessment of progressive alterations in collagen organization in the postoperative conjunctiva by multiphoton microscopy. BIOMEDICAL OPTICS EXPRESS 2020; 11:6495-6515. [PMID: 33282504 PMCID: PMC7687938 DOI: 10.1364/boe.403555] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/14/2020] [Accepted: 09/15/2020] [Indexed: 06/12/2023]
Abstract
Glaucoma filtration surgery (GFS) commonly fails due to excessive fibrosis. As collagen structure aberrations is implicated in adverse fibrotic progression, this study aims to uncover collagen organization alterations during postoperative scarring. Via quantitative second harmonic generation/two photon excitation multiphoton imaging, we reveal the scar development and phenotype in the mouse model of conjunctival scarring. We also show that multiphoton imaging corroborated the collagen ultrastructure anomaly characteristic of the SPARC-/- mouse postoperative conjunctiva. These data improve our understanding of postoperative conjunctival scarring and further enhance the utility of this model for the development of anti-fibrotic therapeutics for GFS.
Collapse
Affiliation(s)
- Li-Fong Seet
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Duke-NUS Medical School, Singapore
- Co-corresponding authors
| | - Stephanie W L Chu
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore
| | | | - Li Zhen Toh
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore
| | - Tina T Wong
- Ocular Therapeutics and Drug Delivery, Singapore Eye Research Institute, Singapore
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Duke-NUS Medical School, Singapore
- Glaucoma Service, Singapore National Eye Centre, Singapore
- Co-corresponding authors
| |
Collapse
|
12
|
Hong XJJ, Suchand Sandeep CS, Shinoj VK, Aung T, Barathi VA, Baskaran M, Murukeshan VM. Noninvasive and Noncontact Sequential Imaging of the Iridocorneal Angle and the Cornea of the Eye. Transl Vis Sci Technol 2020; 9:1. [PMID: 32821473 PMCID: PMC7401920 DOI: 10.1167/tvst.9.5.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 12/22/2019] [Indexed: 12/26/2022] Open
Abstract
Purpose High-resolution imaging of the critical anatomic structures of the eye, especially of the anterior chamber, in vivo, remains a challenge, even with currently available state-of-the-art medical imaging techniques. This study aims for the noninvasive and noncontact sequential imaging of the iridocorneal angle, especially the trabecular meshwork (TM) and the cornea of the eye in high-resolution using a newly developed imaging platform. Methods Bessel beam scanned light sheet fluorescence microscopy is used to attain high-resolution images of the TM. The ability of the Bessel beam to self-reconstruct around obstacles increases the image contrast at the TM region inside eye by reducing scattering and shadow artifacts. With minimal modifications, the excitation arm of the developed imaging system is adapted for noncontact, high-resolution corneal imaging. Results High-resolution images of the TM structures and cellular-level corneal structures are obtained in ex vivo porcine eyes, and subsequently in New Zealand white rabbit, in vivo. The spatial resolution of the developed system is 2.19 µm and has a noncontact working distance of 20 mm. Conclusions A high-resolution imaging platform for noncontact sequential imaging of the TM and the cornea of the eye is developed. This imaging system is expected to be of potential interest in the evaluation and diagnosis of glaucoma and corneal diseases. Translational Relevance The developed prototype offers the plausibility of in vivo, noncontact, and high-resolution imaging of the iridocorneal angle and cornea of the eye that will aid clinicians in diagnosing open-angle glaucoma and corneal diseases better.
Collapse
Affiliation(s)
- Xun Jie Jeesmond Hong
- Centre for Optical and Laser Engineering, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore
| | - C S Suchand Sandeep
- Centre for Optical and Laser Engineering, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore.,Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore
| | - V K Shinoj
- Centre for Optical and Laser Engineering, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore.,Currently with Union Christian College, Department of Physics, Kerala, India
| | - Tin Aung
- Singapore Eye Research Institute (SERI) & Singapore National Eye Center (SNEC), Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Veluchamy Amutha Barathi
- Singapore Eye Research Institute (SERI) & Singapore National Eye Center (SNEC), Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,The Ophthalmology & Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore
| | - Mani Baskaran
- Singapore Eye Research Institute (SERI) & Singapore National Eye Center (SNEC), Singapore.,The Ophthalmology & Visual Sciences Academic Clinical Program, Duke-NUS Medical School, Singapore
| | - Vadakke Matham Murukeshan
- Centre for Optical and Laser Engineering, School of Mechanical and Aerospace Engineering, Nanyang Technological University, Singapore
| |
Collapse
|
13
|
Li Q, Karnowski K, Untracht G, Noble PB, Cense B, Villiger M, Sampson DD. Vectorial birefringence imaging by optical coherence microscopy for assessing fibrillar microstructures in the cornea and limbus. BIOMEDICAL OPTICS EXPRESS 2020; 11:1122-1138. [PMID: 32206403 PMCID: PMC7041478 DOI: 10.1364/boe.382755] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 12/29/2019] [Accepted: 01/06/2020] [Indexed: 05/03/2023]
Abstract
The organization of fibrillar tissue on the micrometer scale carries direct implications for health and disease but remains difficult to assess in vivo. Polarization-sensitive optical coherence tomography measures birefringence, which relates to the microscopic arrangement of fibrillar tissue components. Here, we demonstrate a critical improvement in leveraging this contrast mechanism by employing the improved spatial resolution of focus-extended optical coherence microscopy (1.4 µm axially in air and 1.6 µm laterally, over more than 70 µm depth of field). Vectorial birefringence imaging of sheep cornea ex vivo reveals its lamellar organization into thin sections with distinct local optic axis orientations, paving the way to resolving similar features in vivo.
Collapse
Affiliation(s)
- Qingyun Li
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic & Computer Engineering, The University of Western Australia, Perth, WA 6009, Australia
| | - Karol Karnowski
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic & Computer Engineering, The University of Western Australia, Perth, WA 6009, Australia
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Gavrielle Untracht
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic & Computer Engineering, The University of Western Australia, Perth, WA 6009, Australia
| | - Peter B. Noble
- School of Human Sciences, The University of Western Australia, Perth, WA 6009, Australia
| | - Barry Cense
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic & Computer Engineering, The University of Western Australia, Perth, WA 6009, Australia
| | - Martin Villiger
- Wellman Center for Photomedicine, Harvard Medical School and Massachusetts General Hospital, Boston, MA 02114, USA
| | - David D. Sampson
- Optical+Biomedical Engineering Laboratory, Department of Electrical, Electronic & Computer Engineering, The University of Western Australia, Perth, WA 6009, Australia
- Surrey Biophotonics, School of Physics and School of Biosciences and Medicine, University of Surrey, Guildford, Surrey GU2 7XH, United Kingdom
| |
Collapse
|
14
|
Guo S, Sarfaraz NR, Gensheimer WG, Krieger A, Kang JU. Demonstration of Optical Coherence Tomography Guided Big Bubble Technique for Deep Anterior Lamellar Keratoplasty (DALK). SENSORS 2020; 20:s20020428. [PMID: 31940877 PMCID: PMC7013995 DOI: 10.3390/s20020428] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 01/07/2020] [Accepted: 01/08/2020] [Indexed: 12/03/2022]
Abstract
Deep anterior lamellar keratoplasty (DALK) is a highly challenging procedure for cornea transplant that involves removing the corneal layers above Descemet’s membrane (DM). This is achieved by a “big bubble” technique where a needle is inserted into the stroma of the cornea down to DM and the injection of either air or liquid. DALK has important advantages over penetrating keratoplasty (PK) including lower rejection rate, less endothelial cell loss, and increased graft survival. In this paper, we successfully designed and evaluated the optical coherence tomography (OCT) distal sensor integrated needle for a precise big bubble technique. We successfully used this sensor for micro-control of a robotic DALK device termed AUTO-DALK for autonomous big bubble needle insertion. The OCT distal sensor was integrated inside a 25-gauge needle, which was used for pneumo-dissection. The AUTO-DALK device is built on a manual trephine platform which includes a vacuum ring to fix the device on the eye and add a needle driver at an angle of 60 degrees from vertical. During the test on five porcine eyes with a target depth of 90%, the measured insertion depth as a percentage of cornea thickness for the AUTO-DALK device was 90.05%±2.33% without any perforation compared to 79.16%±5.68% for unassisted free-hand insertion and 86.20%±5.31% for assisted free-hand insertion. The result showed a higher precision and consistency of the needle placement with AUTO-DALK, which could lead to better visual outcomes and fewer complications.
Collapse
Affiliation(s)
- Shoujing Guo
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD 21218, USA;
- Correspondence: ; Tel.: +1-443-858-6100
| | - Nicolas R. Sarfaraz
- Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA; (N.R.S.); (A.K.)
| | - William G. Gensheimer
- Warfighter Eye Center, Malcolm Grow Medical Clinics and Surgery Center, Joint Base Andrews, MD 20762, USA;
| | - Axel Krieger
- Department of Mechanical Engineering, University of Maryland, College Park, MD 20742, USA; (N.R.S.); (A.K.)
| | - Jin U. Kang
- Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD 21218, USA;
| |
Collapse
|
15
|
Boote C, Sigal IA, Grytz R, Hua Y, Nguyen TD, Girard MJA. Scleral structure and biomechanics. Prog Retin Eye Res 2019; 74:100773. [PMID: 31412277 DOI: 10.1016/j.preteyeres.2019.100773] [Citation(s) in RCA: 130] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 08/07/2019] [Accepted: 08/08/2019] [Indexed: 12/18/2022]
Abstract
As the eye's main load-bearing connective tissue, the sclera is centrally important to vision. In addition to cooperatively maintaining refractive status with the cornea, the sclera must also provide stable mechanical support to vulnerable internal ocular structures such as the retina and optic nerve head. Moreover, it must achieve this under complex, dynamic loading conditions imposed by eye movements and fluid pressures. Recent years have seen significant advances in our knowledge of scleral biomechanics, its modulation with ageing and disease, and their relationship to the hierarchical structure of the collagen-rich scleral extracellular matrix (ECM) and its resident cells. This review focuses on notable recent structural and biomechanical studies, setting their findings in the context of the wider scleral literature. It reviews recent progress in the development of scattering and bioimaging methods to resolve scleral ECM structure at multiple scales. In vivo and ex vivo experimental methods to characterise scleral biomechanics are explored, along with computational techniques that combine structural and biomechanical data to simulate ocular behaviour and extract tissue material properties. Studies into alterations of scleral structure and biomechanics in myopia and glaucoma are presented, and their results reconciled with associated findings on changes in the ageing eye. Finally, new developments in scleral surgery and emerging minimally invasive therapies are highlighted that could offer new hope in the fight against escalating scleral-related vision disorder worldwide.
Collapse
Affiliation(s)
- Craig Boote
- Structural Biophysics Research Group, School of Optometry & Vision Sciences, Cardiff University, UK; Ophthalmic Engineering & Innovation Laboratory (OEIL), Department of Biomedical Engineering, National University of Singapore, Singapore; Newcastle Research & Innovation Institute Singapore (NewRIIS), Singapore.
| | - Ian A Sigal
- Laboratory of Ocular Biomechanics, Department of Ophthalmology, University of Pittsburgh, USA
| | - Rafael Grytz
- Department of Ophthalmology & Visual Sciences, University of Alabama at Birmingham, USA
| | - Yi Hua
- Laboratory of Ocular Biomechanics, Department of Ophthalmology, University of Pittsburgh, USA
| | - Thao D Nguyen
- Department of Mechanical Engineering, Johns Hopkins University, USA
| | - Michael J A Girard
- Ophthalmic Engineering & Innovation Laboratory (OEIL), Department of Biomedical Engineering, National University of Singapore, Singapore; Singapore Eye Research Institute (SERI), Singapore National Eye Centre, Singapore
| |
Collapse
|
16
|
Intravital multiphoton microscopic imaging platform for ocular surface imaging. Exp Eye Res 2019; 182:194-201. [PMID: 30822399 DOI: 10.1016/j.exer.2019.02.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 02/08/2019] [Accepted: 02/20/2019] [Indexed: 01/19/2023]
Abstract
The purpose of this study is to provide an intravital noninvasive multiphoton microscopic platform for long-term ocular imaging in transgenic fluorescent mice with subcellular resolution. A multiphoton microscopic system with tunable laser output was employed. We designed a mouse holder incorporated with stereotaxic motorized stage for in vivo three-dimensional imaging of ocular surface in 3 transgenic mouse line with fluorescent protein (FP) expression to visualize distinct structures. With our imaging platform and the expression of FPs, we obtained the three-dimensional images across the whole cornea from epithelium to endothelium and in conjunctiva with subcellular resolution in vivo. Specified EGFP expression in corneal epithelium of K5-H2B-EGFP mice helped to identify both corneal and limbal epithelial cells while ubiquitous nuclear FP expression in R26R-GR mice allowed us to visualized nuclei of all cell types. Universal membrane-localized FP in mT/mG mice outlined all cell boundaries, nerve fibers, and capillaries. The simultaneously collected second harmonic generation signals from collagenous stroma provided architectural contrast. Time-lapsed recording enabled monitoring the mitotic activity of corneal epithelial cells and limbal epithelial cells. We developed an intravital multiphoton microscopic stereotaxic imaging platform and showed that, by incorporating FP-expressing transgenic mice, this platform enables in vivo 4-dimensional ophthalmic study at subcellular resolution.
Collapse
|
17
|
Seyed-Razavi Y, Lopez MJ, Mantopoulos D, Zheng L, Massberg S, Sendra VG, Harris DL, Hamrah P. Kinetics of corneal leukocytes by intravital multiphoton microscopy. FASEB J 2019; 33:2199-2211. [PMID: 30226811 PMCID: PMC6338630 DOI: 10.1096/fj.201800684rr] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 08/27/2018] [Indexed: 12/13/2022]
Abstract
Corneal immune privilege is integral in maintaining the clear avascular window to the foreign world. The presence of distinct populations of corneal leukocytes (CLs) in the normal cornea has been firmly established. However, their precise function and kinetics remain, as of yet, unclear. Through intravital multiphoton microscopy (IV-MPM), allowing the means to accumulate critical spatial and temporal cellular information, we provide details for long-term investigation of CL morphology and kinetics under steady state and following inflammation. Significant alterations in size and morphology of corneal CD11c+ dendritic cells (DCs) were noted following acute sterile inflammation, including cell volume (4364.4 ± 489.6 vs. 1787.6 ± 111.0 μm3, P < 0.001) and sphericity (0.82 ± 0.01 vs. 0.42 ± 0.02, P < 0.001) compared with steady state. Furthermore, IV-MPM analyses revealed alterations in both the CD11c+ DC and major histocompatibility complex class II (MHC)-II+ mature antigen-presenting cell population kinetics during inflammation, including track displacement length (CD11c: 16.57 ± 1.41 vs. 4.64 ± 0.56 μm, P < 0.001; MHC-II: 9.03 ± 0.37 vs. 4.09 ± 0.39, P < 0.001) and velocity (CD11c: 1.91 ± 0.07 μm/min vs. 1.73 ± 0.1302 μm/min; MHC-II: 2.97 ± 0.07 vs. 1.62 ± 0.08, P < 0.001) compared with steady state. Our results reveal in vivo evidence of sessile CL populations exhibiting dendritic morphology under steady state and increased velocity of spherical leukocytes following inflammation. IV-MPM represents a powerful tool to study leukocytes in corneal diseases in context.-Seyed-Razavi, Y., Lopez, M. J., Mantopoulos, D., Zheng, L., Massberg, S., Sendra, V. G., Harris, D. L., Hamrah, P. Kinetics of corneal leukocytes by intravital multiphoton microscopy.
Collapse
Affiliation(s)
- Yashar Seyed-Razavi
- Center for Translational Ocular Immunology, Tufts Medical Center, Tufts University School of Medicine, Tufts University, Boston, Massachusetts, USA
- Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Tufts University, Boston, Massachusetts, USA
- Schepens Eye Research Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
| | - Maria J. Lopez
- Center for Translational Ocular Immunology, Tufts Medical Center, Tufts University School of Medicine, Tufts University, Boston, Massachusetts, USA
- Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Tufts University, Boston, Massachusetts, USA
- Schepens Eye Research Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
| | - Dimosthenis Mantopoulos
- Schepens Eye Research Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
- Division of Immunology, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Lixin Zheng
- Schepens Eye Research Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
- Division of Immunology, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, USA
| | - Steffen Massberg
- Division of Immunology, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, USA
- Department of Cardiology, Ludwig Maximilians Universität, Munich, Germany
| | - Victor G. Sendra
- Center for Translational Ocular Immunology, Tufts Medical Center, Tufts University School of Medicine, Tufts University, Boston, Massachusetts, USA
- Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Tufts University, Boston, Massachusetts, USA
- Schepens Eye Research Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
| | - Deshea L. Harris
- Center for Translational Ocular Immunology, Tufts Medical Center, Tufts University School of Medicine, Tufts University, Boston, Massachusetts, USA
- Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Tufts University, Boston, Massachusetts, USA
- Schepens Eye Research Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
| | - Pedram Hamrah
- Center for Translational Ocular Immunology, Tufts Medical Center, Tufts University School of Medicine, Tufts University, Boston, Massachusetts, USA
- Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Tufts University, Boston, Massachusetts, USA
- Schepens Eye Research Institute, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
- Division of Immunology, Department of Microbiology and Immunobiology, Harvard Medical School, Boston, Massachusetts, USA
- Sackler School of Graduate Biomedical Sciences, Tufts University, Boston, Massachusetts, USA
- Cornea Service, Tufts New England Eye Center, Boston, Massachusetts, USA
- Cornea Service, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
18
|
Batista A, Breunig HG, König A, Morgado AM, König K. Assessment of the metabolism and morphology of the porcine cornea, lens and retina by 2-photon imaging. JOURNAL OF BIOPHOTONICS 2018; 11:e201700324. [PMID: 29575612 DOI: 10.1002/jbio.201700324] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 03/21/2018] [Indexed: 06/08/2023]
Abstract
Two-photon imaging is a noninvasive imaging technique with increasing importance in the biological and medical fields since it allows intratissue cell imaging with high resolution. We demonstrate the feasibility of using a single 2-photon instrument to evaluate the cornea, the crystalline lens and the retina based on their autofluorescence (AF). Image acquisition was performed using a custom-built 2-photon microscope for 5-dimensional microscopy with a near infrared broadband sub-15 femtosecond laser centered at 800 nanometers. Signals were detected using a spectral photomultiplier tube. The spectral ranges for the analysis of each tissue/layer AF were determined based on the spectra of each tissue as well as of pure endogenous fluorophores. The cornea, lens and retina are characterized at multiple depths with subcellular resolution based on their morphology and AF lifetime. Additionally, the AF lifetime of NAD(P)H was used to assess the metabolic activity of the cornea epithelium, endothelium and keratocytes. The feasibility to evaluate the metabolic activity of lens epithelial cells was also demonstrated, which may be used to further investigate the pathogenesis of cataracts. The results illustrate the potential of multimodal multiphoton imaging as a novel ophthalmologic technique as well as its potential as a diagnostic tool.
Collapse
Affiliation(s)
- Ana Batista
- Biophotonics and Laser Technology, Saarland University, Saarbrücken, Germany
- JenLab GmbH, Saarbrücken, Germany
| | - Hans G Breunig
- Biophotonics and Laser Technology, Saarland University, Saarbrücken, Germany
- JenLab GmbH, Saarbrücken, Germany
| | - Aisada König
- Biophotonics and Laser Technology, Saarland University, Saarbrücken, Germany
- JenLab GmbH, Saarbrücken, Germany
| | - António M Morgado
- Department of Physics, University of Coimbra, Coimbra, Portugal
- Coimbra Institute for Biomedical Imaging and Translational Research/Institute of Nuclear Sciences Applied to Heath (CIBIT/ICNAS), University of Coimbra, Coimbra, Portugal
| | - Karsten König
- Biophotonics and Laser Technology, Saarland University, Saarbrücken, Germany
- JenLab GmbH, Saarbrücken, Germany
| |
Collapse
|
19
|
Evolution of the vertebrate corneal stroma. Prog Retin Eye Res 2018; 64:65-76. [DOI: 10.1016/j.preteyeres.2018.01.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 01/12/2018] [Accepted: 01/15/2018] [Indexed: 12/14/2022]
|
20
|
Slimani A, Tardivo D, Panayotov IV, Levallois B, Gergely C, Cuisinier F, Tassery H, Cloitre T, Terrer E. Multiphoton Microscopy for Caries Detection with ICDAS Classification. Caries Res 2018; 52:359-366. [PMID: 29510396 DOI: 10.1159/000486428] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 12/15/2017] [Indexed: 11/19/2022] Open
Abstract
Dentin carious lesion is a dynamic process that involves demineralization and collagen denaturation. Collagen type I is the major protein in dentin and it has been investigated based on its optical properties. Multiphoton microscopy (MPM) is a nonlinear imaging technique that reveals the caries process using the collagen two-photon excitation fluorescence (2PEF) and its second-harmonic generation (SHG). Combining the histological and the International Caries Detection and Assessment System (ICDAS) classifications with nonlinear optical spectroscopy (NLOS), 2PEF and SHG intensities of enamel and dentin were highly altered during the caries process. It has been proven that the ratio SHG/2PEF is a relevant indicator of the organic matrix denaturation [Terrer et al.: J Dent Res 2016; 96: 574-579]. In the present study, a series of measurable signals is made to detect early stages of carious lesion according to the ICDAS classification and to explore the relationship between these measures and the ICDAS scale. Comparison of the efficiency of nonlinear optical signals for caries detection with the ICDAS classification is essential to evaluate their potential for clinical application. In our study, the use of the NLOS measured by MPM allowed us to monitor a quantitative parameter (SHG/2PEF ratio) according to the dentin carious lesion state (ICDAS and histological examination). Three coherent new groups were defined (ICDAS 0/1; ICDAS 2/3; ICDAS 4/5/6), where the carious process can be clearly described with a statistically significant decrease of the SHG/2PEF ratio.
Collapse
Affiliation(s)
- Amel Slimani
- Laboratoire Bioingénierie et Nanosciences, Université de Montpellier, Montpellier, France
| | - Delphine Tardivo
- Laboratoire Anthropologie bio-culturelle, droit, éthique et santé, UMR 7268 CNRS-Université d'Aix-Marseille, Marseille, France
| | - Ivan V Panayotov
- Laboratoire Bioingénierie et Nanosciences, Université de Montpellier, Montpellier, France
| | - Bernard Levallois
- Laboratoire Bioingénierie et Nanosciences, Université de Montpellier, Montpellier, France
| | - Csilla Gergely
- Laboratoire Charles Coulomb, UMR 5221 CNRS-Université de Montpellier, Montpellier, France
| | - Frederic Cuisinier
- Laboratoire Bioingénierie et Nanosciences, Université de Montpellier, Montpellier, France
| | - Hervé Tassery
- Laboratoire Bioingénierie et Nanosciences, Université de Montpellier, Montpellier, France.,Université d'Aix-Marseille, Marseille, France
| | - Thierry Cloitre
- Laboratoire Charles Coulomb, UMR 5221 CNRS-Université de Montpellier, Montpellier, France
| | - Elodie Terrer
- Laboratoire Bioingénierie et Nanosciences, Université de Montpellier, Montpellier, France.,Université d'Aix-Marseille, Marseille, France
| |
Collapse
|
21
|
Batista A, Breunig HG, König A, Schindele A, Hager T, Seitz B, König K. High-resolution, label-free two-photon imaging of diseased human corneas. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-8. [PMID: 29500874 DOI: 10.1117/1.jbo.23.3.036002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 02/08/2018] [Indexed: 05/02/2023]
Abstract
The diagnosis of corneal diseases may be improved by monitoring the metabolism of cells and the structural organization of the stroma using two-photon imaging (TPI). We used TPI to assess the differences between nonpathological (NP) human corneas and corneas diagnosed with either keratoconus, Acanthamoeba keratitis, or stromal corneal scars. Images were acquired using a custom-built five-dimensional laser-scanning microscope with a broadband sub-15 femtosecond near-infrared pulsed excitation laser and a 16-channel photomultiplier tube detector in combination with a time-correlated single photon counting module. Morphological alterations of epithelial cells were observed for all pathologies. Moreover, diseased corneas showed alterations to the cells' metabolism that were revealed using the NAD(P)H free to protein-bound ratios. The mean autofluorescence lifetime of the stroma and the organization of the collagen fibers were also significantly altered due to the pathologies. We demonstrate that TPI can be used to distinguish between NP and diseased human corneas, based not only on alterations of the cells' morphology, which can also be evaluated using current clinical devices, but on additional morphological and functional features such as the organization of the stroma and the cells' metabolism. Therefore, TPI could become an efficient tool for diagnosing corneal diseases and better understanding the biological processes of the diseases.
Collapse
Affiliation(s)
- Ana Batista
- Saarland University, Department of Biophotonics and Laser Technology, Saarbrücken, Germany
- JenLab GmbH, Jena, Germany
| | - Hans Georg Breunig
- Saarland University, Department of Biophotonics and Laser Technology, Saarbrücken, Germany
- JenLab GmbH, Jena, Germany
| | - Aisada König
- Saarland University, Department of Biophotonics and Laser Technology, Saarbrücken, Germany
- JenLab GmbH, Jena, Germany
| | | | - Tobias Hager
- Saarland University, Department of Ophthalmology, Medical Center, Homburg/Saar, Germany
- Saarland University, Lions Cornea Bank Saar-Lor-Lux, Trier/Westpfalz, Medical Center, Homburg/Saar, Germany
| | - Berthold Seitz
- Saarland University, Department of Ophthalmology, Medical Center, Homburg/Saar, Germany
- Saarland University, Lions Cornea Bank Saar-Lor-Lux, Trier/Westpfalz, Medical Center, Homburg/Saar, Germany
| | - Karsten König
- Saarland University, Department of Biophotonics and Laser Technology, Saarbrücken, Germany
- JenLab GmbH, Jena, Germany
| |
Collapse
|
22
|
Raman Microscopy: A Noninvasive Method to Visualize the Localizations of Biomolecules in the Cornea. Cornea 2018; 36 Suppl 1:S67-S71. [PMID: 28902016 DOI: 10.1097/ico.0000000000001369] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE In vivo and in situ visualization of biomolecules without pretreatment will be important for diagnosis and treatment of ocular disorders in the future. Recently, multiphoton microscopy, based on the nonlinear interactions between molecules and photons, has been applied to reveal the localizations of various molecules in tissues. We aimed to use multimodal multiphoton microscopy to visualize the localizations of specific biomolecules in rat corneas. METHODS Multiphoton images of the corneas were obtained from nonlinear signals of coherent anti-Stokes Raman scattering, third-order sum frequency generation, and second-harmonic generation. RESULTS The localizations of the adhesion complex-containing basement membrane and Bowman layer were clearly visible in the third-order sum frequency generation images. The fine structure of type I collagen was observed in the corneal stroma in the second-harmonic generation images. The localizations of lipids, proteins, and nucleic acids (DNA/RNA) was obtained in the coherent anti-Stokes Raman scattering images. CONCLUSIONS Imaging technologies have progressed significantly and been applied in medical fields. Optical coherence tomography and confocal microscopy are widely used but do not provide information on the molecular structure of the cornea. By contrast, multiphoton microscopy provides information on the molecular structure of living tissues. Using this technique, we successfully visualized the localizations of various biomolecules including lipids, proteins, and nucleic acids in the cornea. We speculate that multiphoton microscopy will provide essential information on the physiological and pathological conditions of the cornea, as well as molecular localizations in tissues without pretreatment.
Collapse
|
23
|
Zyablitskaya M, Munteanu EL, Nagasaki T, Paik DC. Second Harmonic Generation Signals in Rabbit Sclera As a Tool for Evaluation of Therapeutic Tissue Cross-linking (TXL) for Myopia. J Vis Exp 2018. [PMID: 29364259 DOI: 10.3791/56385] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Methods to strengthen tissue by introducing chemical bonds (non-enzymatic cross-linking) into structural proteins (fibrillar collagens) for therapy include photochemical cross-linking and tissue cross-linking (TXL) methods. Such methods for inducing mechanical tissue property changes are being employed to the cornea in corneal thinning (mechanically weakened) disorders such as keratoconus as well as the sclera in progressive myopia, where thinning and weakening of the posterior sclera occurs and likely contributes to axial elongation. The primary target proteins for such tissue strengthening are fibrillar collagens which constitute the great majority of dry weight proteins in the cornea and sclera. Fortuitously, fibrillar collagens are the main source of second harmonic generation signals in the tissue extracellular space. Therefore, modifications of the collagen proteins, such as those induced through cross-linking therapies, could potentially be detected and quantitated through the use of second harmonic generation microscopy (SHGM). Monitoring SHGM signals through the use of a laser scanning microscopy system coupled with an infrared excitation light source is an exciting modern imaging method that is enjoying widespread usage in the biomedical sciences. Thus, the present study was undertaken in order to evaluate the use of SHGM microscopy as a means to measure induced cross-linking effects in ex vivo rabbit sclera, following an injection of a chemical cross-linking agent into the sub-Tenon's space (sT), an injection approach that is standard practice for causing ocular anesthesia during ophthalmologic clinical procedures. The chemical cross-linking agent, sodium hydroxymethylglycinate (SMG), is from a class of cosmetic preservatives known as formaldehyde releasing agents (FARs). Scleral changes following reaction with SMG resulted in increases in SHG signals and correlated with shifts in thermal denaturation temperature, a standard method for evaluating induced tissue cross-linking effects.
Collapse
Affiliation(s)
- Mariya Zyablitskaya
- Department of Ophthalmology, Columbia University College of Physicians and Surgeons
| | - E Laura Munteanu
- Confocal and Specialized Microscopy Shared Resource, Herbert Irving Comprehensive Cancer Center, Columbia University
| | - Takayuki Nagasaki
- Department of Ophthalmology, Columbia University College of Physicians and Surgeons
| | - David C Paik
- Department of Ophthalmology, Columbia University College of Physicians and Surgeons;
| |
Collapse
|
24
|
Stanciu SG, Ávila FJ, Hristu R, Bueno JM. A Study on Image Quality in Polarization-Resolved Second Harmonic Generation Microscopy. Sci Rep 2017; 7:15476. [PMID: 29133836 PMCID: PMC5684207 DOI: 10.1038/s41598-017-15257-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 10/24/2017] [Indexed: 01/21/2023] Open
Abstract
Second harmonic generation (SHG) microscopy represents a very powerful tool for tissue characterization. Polarization-resolved SHG (PSHG) microscopy extends the potential of SHG, by exploiting the dependence of SHG signals on the polarization state of the excitation beam. Among others, this dependence translates to the fact that SHG images collected under different polarization configurations exhibit distinct characteristics in terms of content and appearance. These characteristics hold deep implications over image quality, as perceived by human observers or by image analysis methods custom designed to automatically extract a quality factor from digital images. Our work addresses this subject, by investigating how basic image properties and the outputs of no-reference image quality assessment methods correlate to human expert opinion in the case of PSHG micrographs. Our evaluation framework is based on SHG imaging of collagen-based ocular tissues under different linear and elliptical polarization states of the incident light.
Collapse
Affiliation(s)
- Stefan G Stanciu
- Center for Microscopy-Microanalysis and Information Processing, University Politehnica of Bucharest, Bucharest, Romania.
| | | | - Radu Hristu
- Center for Microscopy-Microanalysis and Information Processing, University Politehnica of Bucharest, Bucharest, Romania
| | - Juan M Bueno
- Laboratorio de Óptica, Universidad de Murcia, Murcia, Spain.
| |
Collapse
|
25
|
Bueno JM, Ávila FJ, Artal P. Comparison of second harmonic microscopy images of collagen-based ocular tissues with 800 and 1045 nm. BIOMEDICAL OPTICS EXPRESS 2017; 8:5065-5074. [PMID: 29188103 PMCID: PMC5695953 DOI: 10.1364/boe.8.005065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 10/11/2017] [Accepted: 10/17/2017] [Indexed: 06/07/2023]
Abstract
Second harmonic generation (SHG) imaging is a well-suited multiphoton technique allowing visualization of biological tissues mainly composed of collagen with submicron resolution. Despite its inherent confocal properties, imaging of deeper layers within thick samples has still some limitations. Although the use of longer wavelengths might help to overcome this, the dependence between SHG signals and wavelength is still under discussion. We report here on the dependence with wavelength of SHG signals from collagen-based ocular tissues. The quality of SHG images for two commonly used excitation wavelengths (800 and 1045 nm) is studied. The analysis of the collagen structural information reveals that the information provided by both wavelengths is similar. It was also found that, independently of the depth location, 1045-nm SHG images presented always lower signal levels than those acquired with 800 nm. However, the contrast of the former images was higher, what may improve the visualization of certain features of interest.
Collapse
|
26
|
Jan NJ, Lathrop K, Sigal IA. Collagen Architecture of the Posterior Pole: High-Resolution Wide Field of View Visualization and Analysis Using Polarized Light Microscopy. Invest Ophthalmol Vis Sci 2017; 58:735-744. [PMID: 28146238 PMCID: PMC5295768 DOI: 10.1167/iovs.16-20772] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The purpose of this study was to leverage polarized light microscopy (PLM) to visualize the collagen fiber architecture of posterior pole and optic nerve head with micrometer-scale resolution and to identify and quantify major organizational components. Methods Eight sheep posterior poles were cryosectioned and imaged using PLM. Collagen fiber orientation was determined by using custom scripts, and the resulting orientation maps were inspected and quantified to identify major structural elements and tested for differences in mean fiber orientation and anisotropy, using linear mixed effect models. Results Images revealed an intricate organization of collagen fibers in the posterior pole. In the lamina cribrosa, interweaving fibers formed large knots and wrapped around nerve fiber pores, with beam insertions into the scleral canal wall that were either narrow and straight or wide. In the peripapillary sclera, three significantly different (P < 0.0001) components were identified: fibers oriented circumferentially proximal to the canal, radially in the innermost sclera, and unaligned with interweaving fibers. The radial fibers were between 60 and 180 μm thick, extending at least 3 mm from the canal. Conclusions PLM revealed structural aspects of the lamina cribrosa and sclera that may have important biomechanical roles but that were previously unreported or not characterized quantitatively. In the lamina cribrosa, these roles included wide and narrow beam insertions and details of collagen fibers interweaving and wrapping around the pores. In the sclera, we described regions of circumferential, radial, and unaligned “random” fibers. Although there is consensus that circumferential fibers protect neural tissues by resisting canal expansion, the role of the radial fibers remains unclear.
Collapse
Affiliation(s)
- Ning-Jiun Jan
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States 2Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Kira Lathrop
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States 2Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Ian A Sigal
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, Pennsylvania, United States 2Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| |
Collapse
|
27
|
Zyablitskaya M, Takaoka A, Munteanu EL, Nagasaki T, Trokel SL, Paik DC. Evaluation of Therapeutic Tissue Crosslinking (TXL) for Myopia Using Second Harmonic Generation Signal Microscopy in Rabbit Sclera. Invest Ophthalmol Vis Sci 2017; 58:21-29. [PMID: 28055099 PMCID: PMC5225996 DOI: 10.1167/iovs.16-20241] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Purpose Second harmonic generation signals (SHG) are emitted preferentially from collagenous tissue structures and have been used to evaluate photochemically-induced (CXL) crosslinking changes in the cornea. Since therapeutic tissue crosslinking (TXL) using sodium hydroxymethylglycinate (SMG) of the sclera is a potential treatment for high myopia, we explored the use of SHG microscopy to evaluate the effects. Methods Single sub-Tenon's (sT) injections (400 μL) using SMG (40-400 mM) were made at the equatorial 12 o'clock position of the right eye of cadaveric rabbit heads (n = 16 pairs). After 3.5 hours, confocal microscopy (CM) was performed using 860 nm two-photon excitation and 400 to 450 nm emission. Pixel density and fiber bundle "waviness" analyses were performed on the images. Crosslinking effects were confirmed using thermal denaturation (Tm) temperature. Comparison experiments with riboflavin photochemical crosslinking were done. Results Therapeutic tissue crosslinking localization studies indicated that crosslinking changes occurred at the site of injection and in adjacent sectors. Second harmonic generation signals revealed large fibrous collagenous bundled structures that displayed various degrees of waviness. Histogram analysis showed a nearly 6-fold signal increase in 400 mM SMG over 40 mM. This corresponded to a ΔTm = 13°C for 400 mM versus ΔTm = 4°C for 40 mM. Waviness analysis indicated increased fiber straightening as a result of SMG CXL. Conclusions Second harmonic generation signal intensity and fiber bundle waviness is altered by scleral tissue crosslinking using SMG. These changes provide insights into the macromolecular changes that are induced by therapeutic crosslinking technology and may provide a method to evaluate connective tissue protein changes induced by scleral crosslinking therapies.
Collapse
Affiliation(s)
- Mariya Zyablitskaya
- Department of Ophthalmology, Columbia University College of Physicians and Surgeons, New York, New York, United States
| | - Anna Takaoka
- Department of Ophthalmology, Columbia University College of Physicians and Surgeons, New York, New York, United States
| | - Emilia L Munteanu
- Confocal and Specialized Microscopy Shared Resource, Herbert Irving Comprehensive Cancer Center, Columbia University, New York, New York, United States
| | - Takayuki Nagasaki
- Department of Ophthalmology, Columbia University College of Physicians and Surgeons, New York, New York, United States
| | - Stephen L Trokel
- Department of Ophthalmology, Columbia University College of Physicians and Surgeons, New York, New York, United States
| | - David C Paik
- Department of Ophthalmology, Columbia University College of Physicians and Surgeons, New York, New York, United States
| |
Collapse
|
28
|
Two-Photon Microscopy of the Mouse Peripheral Cornea Ex Vivo. Cornea 2016; 35 Suppl 1:S31-S37. [PMID: 27631351 DOI: 10.1097/ico.0000000000001006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
PURPOSE To investigate the 3-dimensional (3D) cell and extracellular matrix (ECM) structure of mouse peripheral corneas in normal and corneal neovascularization tissues using 2-photon microscopy (TPM) based on both intrinsic and extrinsic moxifloxacin contrasts. METHODS Peripheral corneas in freshly enucleated mouse eyes were imaged by TPM based on both intrinsic and extrinsic contrasts. Intrinsic autofluorescence and second harmonic generation were used to image cells and ECM collagen, respectively. Moxifloxacin ophthalmic solution was applied to image cells. The peripheral cornea, limbus, and sclera were imaged in 3D. In addition to normal mice, mouse models of suture-induced corneal neovascularization were imaged to visualize changes in the microstructure. RESULTS Complex 3D cell and ECM structures in the cornea, limbus, and sclera were visualized by TPM. TPM images based on intrinsic contrasts visualized both cell and ECM structures, and TPM images based on moxifloxacin visualized cell structures with enhanced contrast. On the limbus side of the mouse peripheral cornea, TPM images visualized the vasculature in the limbus, the trabecular meshwork/Schlemm canal, iris, and ciliary body. On the scleral side, TPM images visualized cell and ECM structures in the sclera and multiple cell layers below the sclera. TPM images of the peripheral cornea in the corneal neovascularization condition visualized the extension of vasculature from the limbus to the cornea. CONCLUSIONS TPM imaging based on both intrinsic and external moxifloxacin contrasts visualized detailed 3D cell and ECM microstructures in the mouse peripheral cornea. TPM based on moxifloxacin might be advantageous for studying cell structures by enhancing image contrast.
Collapse
|
29
|
Wang T, Jang WH, Lee S, Yoon CJ, Lee JH, Kim B, Hwang S, Hong CP, Yoon Y, Lee G, Le VH, Bok S, Ahn GO, Lee J, Gho YS, Chung E, Kim S, Jang MH, Myung SJ, Kim MJ, So PTC, Kim KH. Moxifloxacin: Clinically compatible contrast agent for multiphoton imaging. Sci Rep 2016; 6:27142. [PMID: 27283889 PMCID: PMC4901393 DOI: 10.1038/srep27142] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 05/16/2016] [Indexed: 12/11/2022] Open
Abstract
Multiphoton microscopy (MPM) is a nonlinear fluorescence microscopic technique widely used for cellular imaging of thick tissues and live animals in biological studies. However, MPM application to human tissues is limited by weak endogenous fluorescence in tissue and cytotoxicity of exogenous probes. Herein, we describe the applications of moxifloxacin, an FDA-approved antibiotic, as a cell-labeling agent for MPM. Moxifloxacin has bright intrinsic multiphoton fluorescence, good tissue penetration and high intracellular concentration. MPM with moxifloxacin was demonstrated in various cell lines, and animal tissues of cornea, skin, small intestine and bladder. Clinical application is promising since imaging based on moxifloxacin labeling could be 10 times faster than imaging based on endogenous fluorescence.
Collapse
Affiliation(s)
- Taejun Wang
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Rep. of Korea
| | - Won Hyuk Jang
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Rep. of Korea
| | - Seunghun Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Rep. of Korea
| | - Calvin J Yoon
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Rep. of Korea
| | - Jun Ho Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Rep. of Korea
| | - Bumju Kim
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Rep. of Korea
| | - Sekyu Hwang
- Department of Chemistry, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Rep. of Korea
| | - Chun-Pyo Hong
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Rep. of Korea
| | - Yeoreum Yoon
- Department of Mechanical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Rep. of Korea
| | - Gilgu Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Rep. of Korea
| | - Viet-Hoan Le
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Rep. of Korea
| | - Seoyeon Bok
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Rep. of Korea
| | - G-One Ahn
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Rep. of Korea
| | - Jaewook Lee
- Department of Life Sciences, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Rep. of Korea
| | - Yong Song Gho
- Department of Life Sciences, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Rep. of Korea
| | - Euiheon Chung
- Department of Biomedical Science and Engineering, and School of Mechanical Engineering, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Rep. of Korea
| | - Sungjee Kim
- Department of Chemistry, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Rep. of Korea
| | - Myoung Ho Jang
- Academy of Immunology and Microbiology, Institute for Basic Science, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Rep. of Korea
| | - Seung-Jae Myung
- Department of Gastroenterology, University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-ro, 43-gil, Songpa-gu, Seoul 05505, Rep. of Korea
| | - Myoung Joon Kim
- Department of Ophthalmology, Asan University of Ulsan College of Medicine, Asan Medical Center, 88 Olympic-ro, 43-gil, Songpa-gu, Seoul 05505, Rep. of Korea
| | - Peter T C So
- Department of Mechanical Engineering and Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Ki Hean Kim
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Rep. of Korea.,Department of Mechanical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Rep. of Korea
| |
Collapse
|
30
|
Batista A, Breunig HG, Uchugonova A, Morgado AM, König K. Two-photon spectral fluorescence lifetime and second-harmonic generation imaging of the porcine cornea with a 12-femtosecond laser microscope. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:36002. [PMID: 26953661 DOI: 10.1117/1.jbo.21.3.036002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 02/12/2016] [Indexed: 05/08/2023]
Abstract
Five dimensional microscopy with a 12-fs laser scanning microscope based on spectrally resolved two-photon autofluorescence lifetime and second-harmonic generation (SHG) imaging was used to characterize all layers of the porcine cornea. This setup allowed the simultaneous excitation of both metabolic cofactors, NAD(P)H and flavins, and their discrimination based on their spectral emission properties and fluorescence decay characteristics. Furthermore, the architecture of the stromal collagen fibrils was assessed by SHG imaging in both forward and backward directions. Information on the metabolic state and the tissue architecture of the porcine cornea were obtained with subcellular resolution, and high temporal and spectral resolutions.
Collapse
Affiliation(s)
- Ana Batista
- Saarland University, Faculty of Physics and Mechatronics, Department of Biophotonics and Laser Technology, Campus A5.1, Saarbrücken 66123, GermanybUniversity of Coimbra, Faculty of Medicine, Institute for Biomedical Imaging and Life Sciences, Azinhaga San
| | - Hans Georg Breunig
- Saarland University, Faculty of Physics and Mechatronics, Department of Biophotonics and Laser Technology, Campus A5.1, Saarbrücken 66123, GermanycJenLab GmbH, Schillerstr. 1, Jena 07745, Germany
| | - Aisada Uchugonova
- Saarland University, Faculty of Physics and Mechatronics, Department of Biophotonics and Laser Technology, Campus A5.1, Saarbrücken 66123, Germany
| | - António Miguel Morgado
- University of Coimbra, Faculty of Medicine, Institute for Biomedical Imaging and Life Sciences, Azinhaga Santa Comba-Celas, Coimbra 3000-548, PortugaldUniversity of Coimbra, Faculty of Sciences and Technology, Department of Physics, Rua Larga, Coimbra 300
| | - Karsten König
- Saarland University, Faculty of Physics and Mechatronics, Department of Biophotonics and Laser Technology, Campus A5.1, Saarbrücken 66123, GermanycJenLab GmbH, Schillerstr. 1, Jena 07745, Germany
| |
Collapse
|
31
|
Lee JH, Lee S, Yoon CJ, Park JH, Tchah H, Kim MJ, Kim KH. Comparison of reflectance confocal microscopy and two-photon second harmonic generation microscopy in fungal keratitis rabbit model ex vivo. BIOMEDICAL OPTICS EXPRESS 2016; 7:677-687. [PMID: 26977371 PMCID: PMC4771480 DOI: 10.1364/boe.7.000677] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 01/21/2016] [Accepted: 01/21/2016] [Indexed: 06/05/2023]
Abstract
Fungal keratitis is an infection of the cornea by fungal pathogens. Diagnosis methods based on optical microscopy could be beneficial over the conventional microbiology method by allowing rapid and non-invasive examination. Reflectance confocal microscopy (RCM) and two-photon second harmonic generation microscopy (TPSHGM) have been applied to pre-clinical or clinical studies of fungal keratitis. In this report, RCM and TPSHGM were characterized and compared in the imaging of a fungal keratitis rabbit model ex vivo. Fungal infection was induced by using two strains of fungi: aspergillus fumigatus and candida albicans. The infected corneas were imaged in fresh condition by both modalities sequentially and their images were analyzed. Both RCM and TPSHGM could detect both fungal strains within the cornea based on morphology: aspergillus fumigatus had distinctive filamentous structures, and candida albicans had round structures superficially and elongated structures in the corneal stroma. These imaging results were confirmed by histology. Comparison between RCM and TPSHGM showed several characteristics. Although RCM and TPSHGM images had good correlation each other, their images were slightly different due to difference in contrast mechanism. RCM had relatively low image contrast with the infected turbid corneas due to high background signal. TPSHGM visualized cells and collagen in the cornea clearly compared to RCM, but used higher laser power to compensate low autofluorescence. Since these two modalities provide complementary information, combination of RCM and TPSHGM would be useful for fungal keratitis detection by compensating their weaknesses each other.
Collapse
Affiliation(s)
- Jun Ho Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, South Korea
| | - Seunghun Lee
- Department of Mechanical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, South Korea
| | - Calvin J Yoon
- Department of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, South Korea
| | - Jin Hyoung Park
- Department Department of Ophthalmology, University of Ulsan College of Medicine, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro, 43-gil, Songpa-gu, Seoul, 05535, South Korea
| | - Hungwon Tchah
- Department Department of Ophthalmology, University of Ulsan College of Medicine, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro, 43-gil, Songpa-gu, Seoul, 05535, South Korea
| | - Myoung Joon Kim
- Department Department of Ophthalmology, University of Ulsan College of Medicine, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro, 43-gil, Songpa-gu, Seoul, 05535, South Korea;
| | - Ki Hean Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, South Korea; Department of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, South Korea;
| |
Collapse
|
32
|
Terrer E, Panayotov IV, Slimani A, Tardivo D, Gillet D, Levallois B, Fejerskov O, Gergely C, Cuisinier FJG, Tassery H, Cloitre T. Laboratory Studies of Nonlinear Optical Signals for Caries Detection. J Dent Res 2016; 95:574-9. [PMID: 26826107 DOI: 10.1177/0022034516629400] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Multiphoton confocal microscopy and nonlinear spectroscopy are used to investigate the caries process in dentin. Although dentin is a major calcified tissue of the teeth, its organic phase comprises type I collagen fibers. Caries drive dentin demineralization and collagen denaturation. Multiphoton microscopy is a powerful imaging technique: the biological materials are transparent to infrared frequencies and can be excited to penetration depths inaccessible to 1-photon confocal microscopy. The laser excitation greatly reduces photodamage to the sole focal region, and the signal-to-noise ratio is improved significantly. The method has been used to follow pathologic processes involving collagen fibrosis or collagen destruction based on their 2-photon excited fluorescence (2PEF) emission and second harmonic generation (SHG). Combining multiphoton imaging with nonlinear spectroscopy, we demonstrate that both 2PEF and SHG intensity of human dentin are strongly modified during the tooth caries process, and we show that the ratio between SHG and 2PEF signals is a reliable parameter to follow dental caries. The ratio of the SHG/2PEF signals measured by nonlinear optical spectroscopy provides valuable information on the caries process, specifically on the degradation of the organic matrix of dentin. The goal is to bring these nonlinear optical signals to clinical application for caries diagnosis.
Collapse
Affiliation(s)
- E Terrer
- Laboratoire Bio ingénierie et Nanosciences, Université de Montpellier, Montpellier, France Université d'Aix-Marseille, Marseille, France
| | - I V Panayotov
- Laboratoire Bio ingénierie et Nanosciences, Université de Montpellier, Montpellier, France
| | - A Slimani
- Laboratoire Bio ingénierie et Nanosciences, Université de Montpellier, Montpellier, France
| | - D Tardivo
- Laboratoire Anthropologie bio-culturelle, droit, éthique et santé, UMR 7268 CNRS-Université d'Aix-Marseille, Marseille, France
| | - D Gillet
- Laboratoire Bio ingénierie et Nanosciences, Université de Montpellier, Montpellier, France
| | - B Levallois
- Laboratoire Bio ingénierie et Nanosciences, Université de Montpellier, Montpellier, France
| | - O Fejerskov
- Department of Biomedicine-Anatomy Health, Aarhus University, Aarhus, Denmark
| | - C Gergely
- Laboratoire Charles Coulomb, UMR 5221 CNRS-Université de Montpellier, Montpellier, France
| | - F J G Cuisinier
- Laboratoire Bio ingénierie et Nanosciences, Université de Montpellier, Montpellier, France
| | - H Tassery
- Laboratoire Bio ingénierie et Nanosciences, Université de Montpellier, Montpellier, France Université d'Aix-Marseille, Marseille, France
| | - T Cloitre
- Laboratoire Charles Coulomb, UMR 5221 CNRS-Université de Montpellier, Montpellier, France
| |
Collapse
|
33
|
Ávila FJ, Bueno JM. Analysis and quantification of collagen organization with the structure tensor in second harmonic microscopy images of ocular tissues. APPLIED OPTICS 2015; 54:9848-54. [PMID: 26836548 DOI: 10.1364/ao.54.009848] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The important biological role of collagen-based tissues and the changes produced in the fiber distribution under particular situations (surgery, pathology, external damage, etc.) require tools for the analysis of the collagen organization that might potentially help in early diagnoses. Since collagen structures provide efficient second harmonic generation (SHG) signals, SHG microscopy has emerged as a powerful technique to visualize collagen fibers and qualitatively discriminate normal from abnormal tissues. Here we propose a quantitative method based on the structure tensor to quantify the different organization of collagen patterns in SHG images of ocular tissues. Results show that well-organized collagen distributions present a high degree of isotropy (DoI), a dominant orientation (PO), and a low structural dispersion (SD). On the other hand, the PO vanishes when the collagen tissue is not organized as a consequence of an increase in the SD and a decrease in the DoI. The proposed method is also able to discriminate partially organized samples. The combination of SHG microscopy and the structure tensor is a useful method to objectively classify collagen distributions. Clinical applications of this technique could help in the diagnosis and tracking of pathologies related to collagen disorders in connective tissue.
Collapse
|
34
|
Park CY, Lee JK, Zhang C, Chuck RS. New Details of the Human Corneal Limbus Revealed With Second Harmonic Generation Imaging. Invest Ophthalmol Vis Sci 2015; 56:6058-66. [PMID: 26393473 DOI: 10.1167/iovs.15-16783] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To report novel findings of the human corneal limbus by using second harmonic generation (SHG) imaging. METHODS Corneal limbus was imaged by using an inverted two-photon excitation fluorescence microscope. Laser (Ti:Sapphire) was tuned at 850 nm for two-photon excitation. Backscatter signals of SHG and autofluorescence (AF) were collected through a 425/30-nm emission filter and a 525/45-emission filter, respectively. Multiple, consecutive, and overlapping image stacks (z-stack) were acquired for the corneal limbal area. RESULTS Two novel collagen structures were revealed by SHG imaging at the limbus: an anterior limbal cribriform layer and presumed anchoring fibers. Anterior limbal cribriform layer is an intertwined reticular collagen architecture just beneath the limbal epithelial niche and is located between the peripheral cornea and Tenon's/scleral tissue. Autofluorescence imaging revealed high vascularity in this structure. Central to the anterior limbal cribriform layer, radial strands of collagen were found to connect the peripheral cornea to the limbus. These presumed anchoring fibers have both collagen and elastin and were found more extensively in the superficial layers than deep layer and were absent in very deep limbus near Schlemm's canal. CONCLUSIONS By using SHG imaging, new details of the collagen architecture of human corneal limbal area were elucidated. High resolution images with volumetric analysis revealed two novel collagen structures.
Collapse
Affiliation(s)
- Choul Yong Park
- Department of Ophthalmology, Dongguk University, Ilsan Hospital, Goyang, Kyunggido, South Korea 2Department of Ophthalmology and Visual Sciences, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York, United States
| | - Jimmy K Lee
- Department of Ophthalmology and Visual Sciences, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York, United States
| | - Cheng Zhang
- Department of Ophthalmology and Visual Sciences, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York, United States
| | - Roy S Chuck
- Department of Ophthalmology and Visual Sciences, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York, United States
| |
Collapse
|
35
|
Segawa H, Kaji Y, Leproux P, Couderc V, Ozawa T, Oshika T, Kano H. Multimodal and multiplex spectral imaging of rat cornea ex vivo using a white-light laser source. JOURNAL OF BIOPHOTONICS 2015; 8:705-13. [PMID: 25378211 DOI: 10.1002/jbio.201400059] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 07/24/2014] [Accepted: 10/13/2014] [Indexed: 05/24/2023]
Abstract
We applied our multimodal nonlinear spectral imaging microscope to the measurement of rat cornea. We successfully obtained multiple nonlinear signals of coherent anti-Stokes Raman scattering (CARS), third-order sum frequency generation (TSFG), and second harmonic generation (SHG). Depending on the nonlinear optical processes, the cornea tissue was visualized with different image contrast mechanism simultaneously. Due to white-light laser excitation, multiplex CARS and TSFG spectra were obtained. Combined multimodal and spectral analysis clearly elucidated the layered structure of rat cornea with molecular structural information. This study indicates that our multimodal nonlinear spectral microscope is a promising bioimaging method for tissue study. Multimodal nonlinear spectral images of rat cornea at corneal epithelium and corneal stroma in the in-plane (XY) direction. With use of the combinational analysis of different nonlinear optical processes, detailed molecular structural information is available without staining or labelling.
Collapse
Affiliation(s)
- Hiroki Segawa
- Department of Chemistry, School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo, Tokyo, 113-0033, Japan
| | - Yuichi Kaji
- Graduate School of Comprehensive Human Science, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8575, Japan
| | - Philippe Leproux
- Xlim Research Institute, CNRS-University of Limoges, 123 Avenue Albert Thomas, 87060, Limoges cedex, France
| | - Vincent Couderc
- Xlim Research Institute, CNRS-University of Limoges, 123 Avenue Albert Thomas, 87060, Limoges cedex, France
| | - Takeaki Ozawa
- Department of Chemistry, School of Science, The University of Tokyo, 7-3-1, Hongo, Bunkyo, Tokyo, 113-0033, Japan
| | - Tetsuro Oshika
- Graduate School of Comprehensive Human Science, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8575, Japan
| | - Hideaki Kano
- Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8573, Japan.
| |
Collapse
|
36
|
Beack S, Choi JS, Lee JH, Kim H, Kim KH, Joo CK, Hahn SK. Two-photon microscopy of a Flt1 peptide-hyaluronate conjugate. Nanomedicine (Lond) 2015; 10:2315-24. [PMID: 26228271 DOI: 10.2217/nnm.15.71] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIM Two-photon microscopy was performed to visualize ocular distribution of Flt1 peptide-hyaluronate (HA) conjugate micelles for eye drop treatment of corneal neovascularization. MATERIALS & METHODS Flt1 peptide-HA conjugate micelles were topically administered to the eye for two-photon microscopy and antiangiogenic effect assessment after silver nitrate cauterization. RESULTS In vivo two-photon microscopy revealed that Flt1 peptide-HA conjugate micelles were absorbed and remained on the corneal epithelia with an increased residence time, facilitating the corneal delivery of carboxyfluorescein succinimidyl ester (CFSE) as a model drug. Furthermore, repeated eye drops of Flt1 peptide-HA conjugate micelles showed comparable therapeutic effect to the subconjunctival injection on the corneal neovascularization. DISCUSSION & CONCLUSION We confirmed the feasibility of Flt1 peptide-HA conjugate micelles for eye drop treatment of corneal neovascularization.
Collapse
Affiliation(s)
- Songeun Beack
- Department of Materials Science & Engineering, Pohang University of Science & Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang 790-784, Korea
| | - Jun-Sub Choi
- Department of Ophthalmology & Visual Science, Seoul St., Mary's Hospital, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul 137-701, Korea
| | - Jun Ho Lee
- Division of Biosciences & Biotechnology, Pohang University of Science & Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang 790-784, Korea
| | - Hyemin Kim
- Department of Materials Science & Engineering, Pohang University of Science & Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang 790-784, Korea
| | - Ki Hean Kim
- Division of Biosciences & Biotechnology, Pohang University of Science & Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang 790-784, Korea
| | - Choun-Ki Joo
- Department of Ophthalmology & Visual Science, Seoul St., Mary's Hospital, College of Medicine, The Catholic University of Korea, 222 Banpo-daero, Seocho-gu, Seoul 137-701, Korea
| | - Sei Kwang Hahn
- Department of Materials Science & Engineering, Pohang University of Science & Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang 790-784, Korea
| |
Collapse
|
37
|
Meek KM, Knupp C. Corneal structure and transparency. Prog Retin Eye Res 2015; 49:1-16. [PMID: 26145225 PMCID: PMC4655862 DOI: 10.1016/j.preteyeres.2015.07.001] [Citation(s) in RCA: 438] [Impact Index Per Article: 48.7] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Revised: 06/28/2015] [Accepted: 07/01/2015] [Indexed: 12/13/2022]
Abstract
The corneal stroma plays several pivotal roles within the eye. Optically, it is the main refracting lens and thus has to combine almost perfect transmission of visible light with precise shape, in order to focus incoming light. Furthermore, mechanically it has to be extremely tough to protect the inner contents of the eye. These functions are governed by its structure at all hierarchical levels. The basic principles of corneal structure and transparency have been known for some time, but in recent years X-ray scattering and other methods have revealed that the details of this structure are far more complex than previously thought and that the intricacy of the arrangement of the collagenous lamellae provides the shape and the mechanical properties of the tissue. At the molecular level, modern technologies and theoretical modelling have started to explain exactly how the collagen fibrils are arranged within the stromal lamellae and how proteoglycans maintain this ultrastructure. In this review we describe the current state of knowledge about the three-dimensional stromal architecture at the microscopic level, and about the control mechanisms at the nanoscopic level that lead to optical transparency.
Collapse
Affiliation(s)
- Keith M Meek
- Structural Biophysics Research Group, School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff CF24 4HQ, UK.
| | - Carlo Knupp
- Structural Biophysics Research Group, School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cardiff CF24 4HQ, UK
| |
Collapse
|
38
|
Bueno JM, Palacios R, Pennos A, Artal P. Second-harmonic generation microscopy of photocurable polymer intrastromal implants in ex-vivo corneas. BIOMEDICAL OPTICS EXPRESS 2015; 6:2211-9. [PMID: 26114039 PMCID: PMC4473754 DOI: 10.1364/boe.6.002211] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 05/14/2015] [Accepted: 05/14/2015] [Indexed: 05/25/2023]
Abstract
A custom adaptive-optics (AO) multiphoton microscope was used to visualize the corneal stroma after the insertion of a photocurable polymer material. A lamellar pocket was created and a certain amount of polymer in liquid form was injected. This turned into a rigid film after UV irradiation. Intact eyes were used as control. Tomographic and regular second harmonic generation (SHG) microscopy images were recorded from both control and corneas with polymer implants. In control corneas, the SHG signal decreased uniformly with depth. However, treated corneas exhibited an abrupt loss of SHG signal at the implant location. The use of AO increased the SHG levels and improved the visualization of the stroma, not only at deeper corneal layers but also beneath the implant. Moreover, the absence of SHG signal from the implant allowed its geometrical characterization (thickness and location). This technique offers a potential tool for non-invasive analysis of morphological changes in the cornea after surgery or treatment, and might be useful in future clinical environments.
Collapse
|
39
|
Quantock AJ, Winkler M, Parfitt GJ, Young RD, Brown DJ, Boote C, Jester JV. From nano to macro: studying the hierarchical structure of the corneal extracellular matrix. Exp Eye Res 2015; 133:81-99. [PMID: 25819457 DOI: 10.1016/j.exer.2014.07.018] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 07/17/2014] [Accepted: 07/21/2014] [Indexed: 01/22/2023]
Abstract
In this review, we discuss current methods for studying ocular extracellular matrix (ECM) assembly from the 'nano' to the 'macro' levels of hierarchical organization. Since collagen is the major structural protein in the eye, providing mechanical strength and controlling ocular shape, the methods presented focus on understanding the molecular assembly of collagen at the nanometre level using X-ray scattering through to the millimetre to centimetre level using non-linear optical (NLO) imaging of second harmonic generated (SHG) signals. Three-dimensional analysis of ECM structure is also discussed, including electron tomography, serial block face scanning electron microscopy (SBF-SEM) and digital image reconstruction. Techniques to detect non-collagenous structural components of the ECM are also presented, and these include immunoelectron microscopy and staining with cationic dyes. Together, these various approaches are providing new insights into the structural blueprint of the ocular ECM, and in particular that of the cornea, which impacts upon our current understanding of the control of corneal shape, pathogenic mechanisms underlying ectatic disorders of the cornea and the potential for corneal tissue engineering.
Collapse
Affiliation(s)
- Andrew J Quantock
- Structural Biophysics Group, Cardiff Centre for Vision Science, School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, UK
| | - Moritz Winkler
- Department of Ophthalmology and Biomedical Engineering, University of California, Irvine, Irvine, CA, USA
| | - Geraint J Parfitt
- Department of Ophthalmology and Biomedical Engineering, University of California, Irvine, Irvine, CA, USA
| | - Robert D Young
- Structural Biophysics Group, Cardiff Centre for Vision Science, School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, UK
| | - Donald J Brown
- Department of Ophthalmology and Biomedical Engineering, University of California, Irvine, Irvine, CA, USA
| | - Craig Boote
- Structural Biophysics Group, Cardiff Centre for Vision Science, School of Optometry and Vision Sciences, Cardiff University, Cardiff, Wales, UK
| | - James V Jester
- Department of Ophthalmology and Biomedical Engineering, University of California, Irvine, Irvine, CA, USA.
| |
Collapse
|
40
|
Jay L, Bourget JM, Goyer B, Singh K, Brunette I, Ozaki T, Proulx S. Characterization of tissue-engineered posterior corneas using second- and third-harmonic generation microscopy. PLoS One 2015; 10:e0125564. [PMID: 25918849 PMCID: PMC4412819 DOI: 10.1371/journal.pone.0125564] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 03/25/2015] [Indexed: 12/13/2022] Open
Abstract
Three-dimensional tissues, such as the cornea, are now being engineered as substitutes for the rehabilitation of vision in patients with blinding corneal diseases. Engineering of tissues for translational purposes requires a non-invasive monitoring to control the quality of the resulting biomaterial. Unfortunately, most current methods still imply invasive steps, such as fixation and staining, to clearly observe the tissue-engineered cornea, a transparent tissue with weak natural contrast. Second- and third-harmonic generation imaging are well known to provide high-contrast, high spatial resolution images of such tissues, by taking advantage of the endogenous contrast agents of the tissue itself. In this article, we imaged tissue-engineered corneal substitutes using both harmonic microscopy and classic histopathology techniques. We demonstrate that second- and third-harmonic imaging can non-invasively provide important information regarding the quality and the integrity of these partial-thickness posterior corneal substitutes (observation of collagen network, fibroblasts and endothelial cells). These two nonlinear imaging modalities offer the new opportunity of monitoring the engineered corneas during the entire process of production.
Collapse
Affiliation(s)
- Louis Jay
- Centre Énergie Matériaux Télécommunications, Institut National de la Recherche Scientifique, Varennes, Quebec, Canada
- Centre de recherche de l’Hôpital Maisonneuve-Rosemont, Montréal, Quebec, Canada and Département d’ophtalmologie, Université de Montréal, Montréal, Quebec, Canada
| | - Jean-Michel Bourget
- Centre de recherche de l’Hôpital Maisonneuve-Rosemont, Montréal, Quebec, Canada and Département d’ophtalmologie, Université de Montréal, Montréal, Quebec, Canada
| | - Benjamin Goyer
- Axe médecine régénératrice, Hôpital du Saint-Sacrement, Centre de recherche du CHU de Québec, Québec, Quebec, Canada and Centre de recherche en organogénèse expérimentale de l’Université Laval / LOEX, Québec, Quebec, Canada
| | - Kanwarpal Singh
- Centre Énergie Matériaux Télécommunications, Institut National de la Recherche Scientifique, Varennes, Quebec, Canada
- Centre de recherche de l’Hôpital Maisonneuve-Rosemont, Montréal, Quebec, Canada and Département d’ophtalmologie, Université de Montréal, Montréal, Quebec, Canada
| | - Isabelle Brunette
- Centre de recherche de l’Hôpital Maisonneuve-Rosemont, Montréal, Quebec, Canada and Département d’ophtalmologie, Université de Montréal, Montréal, Quebec, Canada
| | - Tsuneyuki Ozaki
- Centre Énergie Matériaux Télécommunications, Institut National de la Recherche Scientifique, Varennes, Quebec, Canada
| | - Stéphanie Proulx
- Axe médecine régénératrice, Hôpital du Saint-Sacrement, Centre de recherche du CHU de Québec, Québec, Quebec, Canada and Centre de recherche en organogénèse expérimentale de l’Université Laval / LOEX, Québec, Quebec, Canada
- Département d’ophtalmologie et d’oto-rhino-laryngologie, Faculté de médecine, Université Laval, Québec, Quebec, Canada
- * E-mail:
| |
Collapse
|
41
|
Comparison of confocal microscopy and two-photon microscopy in mouse cornea in vivo. Exp Eye Res 2015; 132:101-8. [DOI: 10.1016/j.exer.2015.01.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Revised: 01/14/2015] [Accepted: 01/16/2015] [Indexed: 01/17/2023]
|
42
|
Aper SJA, van Spreeuwel ACC, van Turnhout MC, van der Linden AJ, Pieters PA, van der Zon NLL, de la Rambelje SL, Bouten CVC, Merkx M. Colorful protein-based fluorescent probes for collagen imaging. PLoS One 2014; 9:e114983. [PMID: 25490719 PMCID: PMC4260915 DOI: 10.1371/journal.pone.0114983] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 11/17/2014] [Indexed: 02/05/2023] Open
Abstract
Real-time visualization of collagen is important in studies on tissue formation and remodeling in the research fields of developmental biology and tissue engineering. Our group has previously reported on a fluorescent probe for the specific imaging of collagen in live tissue in situ, consisting of the native collagen binding protein CNA35 labeled with fluorescent dye Oregon Green 488 (CNA35-OG488). The CNA35-OG488 probe has become widely used for collagen imaging. To allow for the use of CNA35-based probes in a broader range of applications, we here present a toolbox of six genetically-encoded collagen probes which are fusions of CNA35 to fluorescent proteins that span the visible spectrum: mTurquoise2, EGFP, mAmetrine, LSSmOrange, tdTomato and mCherry. While CNA35-OG488 requires a chemical conjugation step for labeling with the fluorescent dye, these protein-based probes can be easily produced in high yields by expression in E. coli and purified in one step using Ni2+-affinity chromatography. The probes all bind specifically to collagen, both in vitro and in porcine pericardial tissue. Some first applications of the probes are shown in multicolor imaging of engineered tissue and two-photon imaging of collagen in human skin. The fully-genetic encoding of the new probes makes them easily accessible to all scientists interested in collagen formation and remodeling.
Collapse
Affiliation(s)
- Stijn J. A. Aper
- Laboratory of Chemical Biology and Institute of Complex Molecular Systems (ICMS), Department of Biomedical Engineering, Eindhoven University of Technology, MB Eindhoven, The Netherlands
| | - Ariane C. C. van Spreeuwel
- Soft Tissue Biomechanics and Engineering, Department of Biomedical Engineering, Eindhoven University of Technology, MB Eindhoven, The Netherlands
| | - Mark C. van Turnhout
- Soft Tissue Biomechanics and Engineering, Department of Biomedical Engineering, Eindhoven University of Technology, MB Eindhoven, The Netherlands
| | - Ardjan J. van der Linden
- Laboratory of Chemical Biology and Institute of Complex Molecular Systems (ICMS), Department of Biomedical Engineering, Eindhoven University of Technology, MB Eindhoven, The Netherlands
| | - Pascal A. Pieters
- Laboratory of Chemical Biology and Institute of Complex Molecular Systems (ICMS), Department of Biomedical Engineering, Eindhoven University of Technology, MB Eindhoven, The Netherlands
| | - Nick L. L. van der Zon
- Laboratory of Chemical Biology and Institute of Complex Molecular Systems (ICMS), Department of Biomedical Engineering, Eindhoven University of Technology, MB Eindhoven, The Netherlands
| | - Sander L. de la Rambelje
- Laboratory of Chemical Biology and Institute of Complex Molecular Systems (ICMS), Department of Biomedical Engineering, Eindhoven University of Technology, MB Eindhoven, The Netherlands
| | - Carlijn V. C. Bouten
- Soft Tissue Biomechanics and Engineering, Department of Biomedical Engineering, Eindhoven University of Technology, MB Eindhoven, The Netherlands
| | - Maarten Merkx
- Laboratory of Chemical Biology and Institute of Complex Molecular Systems (ICMS), Department of Biomedical Engineering, Eindhoven University of Technology, MB Eindhoven, The Netherlands
- * E-mail:
| |
Collapse
|
43
|
Visualization of mouse neuronal ganglia infected by Herpes Simplex Virus 1 (HSV-1) using multimodal non-linear optical microscopy. PLoS One 2014; 9:e105103. [PMID: 25133579 PMCID: PMC4136817 DOI: 10.1371/journal.pone.0105103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Accepted: 07/17/2014] [Indexed: 12/14/2022] Open
Abstract
Herpes simplex virus 1 (HSV-1) is a neurotropic virus that causes skin lesions and goes on to enter a latent state in neurons of the trigeminal ganglia. Following stress, the virus may reactivate from latency leading to recurrent lesions. The in situ study of neuronal infections by HSV-1 is critical to understanding the mechanisms involved in the biology of this virus and how it causes disease; however, this normally requires fixation and sectioning of the target tissues followed by treatment with contrast agents to visualize key structures, which can lead to artifacts. To further our ability to study HSV-1 neuropathogenesis, we have generated a recombinant virus expressing a second generation red fluorescent protein (mCherry), which behaves like the parental virus in vivo. By optimizing the application of a multimodal non-linear optical microscopy platform, we have successfully visualized in unsectioned trigeminal ganglia of mice both infected cells by two-photon fluorescence microscopy, and myelinated axons of uninfected surrounding cells by coherent anti-Stokes Raman scattering (CARS) microscopy. These results represent the first report of CARS microscopy being combined with 2-photon fluorescence microscopy to visualize virus-infected cells deep within unsectioned explanted tissue, and demonstrate the application of multimodal non-linear optical microscopy for high spatial resolution biological imaging of tissues without the use of stains or fixatives.
Collapse
|
44
|
Yamanari M, Nagase S, Fukuda S, Ishii K, Tanaka R, Yasui T, Oshika T, Miura M, Yasuno Y. Scleral birefringence as measured by polarization-sensitive optical coherence tomography and ocular biometric parameters of human eyes in vivo. BIOMEDICAL OPTICS EXPRESS 2014; 5:1391-402. [PMID: 24877003 PMCID: PMC4026890 DOI: 10.1364/boe.5.001391] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 03/26/2014] [Accepted: 03/31/2014] [Indexed: 05/03/2023]
Abstract
The relationship between scleral birefringence and biometric parameters of human eyes in vivo is investigated. Scleral birefringence near the limbus of 21 healthy human eyes was measured using polarization-sensitive optical coherence tomography. Spherical equivalent refractive error, axial eye length, and intraocular pressure (IOP) were measured in all subjects. IOP and scleral birefringence of human eyes in vivo was found to have statistically significant correlations (r = -0.63, P = 0.002). The slope of linear regression was -2.4 × 10(-2) deg/μm/mmHg. Neither spherical equivalent refractive error nor axial eye length had significant correlations with scleral birefringence. To evaluate the direct influence of IOP to scleral birefringence, scleral birefringence of 16 ex vivo porcine eyes was measured under controlled IOP of 5-60 mmHg. In these ex vivo porcine eyes, the mean linear regression slope between controlled IOP and scleral birefringence was -9.9 × 10(-4) deg/μm/mmHg. In addition, porcine scleral collagen fibers were observed with second-harmonic-generation (SHG) microscopy. SHG images of porcine sclera, measured on the external surface at the superior side to the cornea, showed highly aligned collagen fibers parallel to the limbus. In conclusion, scleral birefringence of healthy human eyes was correlated with IOP, indicating that the ultrastructure of scleral collagen was correlated with IOP. It remains to show whether scleral collagen ultrastructure of human eyes is affected by IOP as a long-term effect.
Collapse
Affiliation(s)
- Masahiro Yamanari
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan
- Computational Optics and Ophthalmology Group, Tsukuba, Ibaraki, Japan
- Tomey Corporation, Nagoya, Aichi, Japan
| | - Satoko Nagase
- Department of Ophthalmology, Tokyo Medical University Ibaraki Medical Center, Ami, Ibaraki, Japan
- Computational Optics and Ophthalmology Group, Tsukuba, Ibaraki, Japan
| | - Shinichi Fukuda
- Department of Ophthalmology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
- Computational Optics and Ophthalmology Group, Tsukuba, Ibaraki, Japan
| | - Kotaro Ishii
- Department of Ophthalmology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
- Computational Optics and Ophthalmology Group, Tsukuba, Ibaraki, Japan
| | - Ryosuke Tanaka
- Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, Japan
| | - Takeshi Yasui
- Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, Japan
- Institute of Technology and Science, The University of Tokushima, Tokushima, Tokushima, Japan
| | - Tetsuro Oshika
- Department of Ophthalmology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
- Computational Optics and Ophthalmology Group, Tsukuba, Ibaraki, Japan
| | - Masahiro Miura
- Department of Ophthalmology, Tokyo Medical University Ibaraki Medical Center, Ami, Ibaraki, Japan
- Computational Optics and Ophthalmology Group, Tsukuba, Ibaraki, Japan
| | - Yoshiaki Yasuno
- Computational Optics Group, University of Tsukuba, Tsukuba, Ibaraki, Japan
- Computational Optics and Ophthalmology Group, Tsukuba, Ibaraki, Japan
| |
Collapse
|
45
|
Huang AS, Gonzalez JM, Le PV, Heur M, Tan JCH. Sources of structural autofluorescence in the human trabecular meshwork. Invest Ophthalmol Vis Sci 2013; 54:4813-20. [PMID: 23745000 PMCID: PMC3720147 DOI: 10.1167/iovs.12-11235] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Accepted: 05/28/2013] [Indexed: 11/24/2022] Open
Abstract
PURPOSE In situ 2-photon excitation fluorescence (TPEF) of the human trabecular meshwork (TM) reveals beams of heterogeneous autofluorescence (AF) comprising high intensity fluorescent fibers (AF-high) on a background of lower intensity fluorescence (AF-low). To determine the sources of this AF heterogeneity, we imaged human TM to characterize AF, second harmonic generation (SHG) for collagen, and eosin-labeled fluorescence identifying elastin. METHODS Corneoscleral rims retained after corneal transplantation were incubated with and without eosin, and imaged by TPEF. TPEF was collected through multiphoton bandpass filters to obtain AF, SHG (collagen bandwidth), and eosin-labeled fluorescence images. For qualitative comparisons, near-simultaneous image acquisition pairs of AF-SHG (+/-eosin coincubation), AF-eosin, and SHG-eosin were captured. For quantitative comparisons, multiple regions of interest (ROI) were defined in separate TM beam regions within the uveal and corneoscleral meshwork for image acquisition pairs of AF-SHG (without eosin coincubation) and SHG-eosin. We defined 18 ROI within each acquisition pair as the basis for Manders colocalization analysis. Perfect colocalization was defined as a Manders coefficient (Mcoeff) of 1. RESULTS Qualitatively and quantitatively, AF-low colocalized with SHG (Mcoeff=1), but not SHG signal-voids. AF-high colocalized with SHG signal-voids (Mcoeff=1), but not the SHG signal. Like AF-high, eosin-labeled fluorescence qualitatively and quantitatively colocalized (Mcoeff=1) with SHG signal-voids, but not the SHG signal. CONCLUSIONS Heterogeneous AF in human TM is comprised of high intensity signal originating from elastin fibers in beam cores and lower intensity signal originating from collagen. These findings are relevant to interpreting structural extracellular matrix signals in AF images of the TM.
Collapse
Affiliation(s)
- Alex S Huang
- Doheny Eye Institute and Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, California 90033, USA
| | | | | | | | | |
Collapse
|
46
|
Keeping an eye on decellularized corneas: a review of methods, characterization and applications. J Funct Biomater 2013; 4:114-61. [PMID: 24956084 PMCID: PMC4030906 DOI: 10.3390/jfb4030114] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 05/08/2013] [Accepted: 05/28/2013] [Indexed: 12/13/2022] Open
Abstract
The worldwide limited availability of suitable corneal donor tissue has led to the development of alternatives, including keratoprostheses (Kpros) and tissue engineered (TE) constructs. Despite advances in bioscaffold design, there is yet to be a corneal equivalent that effectively mimics both the native tissue ultrastructure and biomechanical properties. Human decellularized corneas (DCs) could offer a safe, sustainable source of corneal tissue, increasing the donor pool and potentially reducing the risk of immune rejection after corneal graft surgery. Appropriate, human-specific, decellularization techniques and high-resolution, non-destructive analysis systems are required to ensure reproducible outputs can be achieved. If robust treatment and characterization processes can be developed, DCs could offer a supplement to the donor corneal pool, alongside superior cell culture systems for pharmacology, toxicology and drug discovery studies.
Collapse
|
47
|
Masihzadeh O, Ammar DA, Kahook MY, Gibson EA, Lei TC. Direct trabecular meshwork imaging in porcine eyes through multiphoton gonioscopy. JOURNAL OF BIOMEDICAL OPTICS 2013; 18:036009. [PMID: 23515864 PMCID: PMC5997970 DOI: 10.1117/1.jbo.18.3.036009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2012] [Revised: 02/19/2013] [Accepted: 02/21/2013] [Indexed: 05/19/2023]
Abstract
The development of technologies to characterize the ocular aqueous outflow system (AOS) is important for the understanding of the pathophysiology of glaucoma. Multiphoton microscopy (MPM) offers the advantage of high-resolution, label-free imaging with intrinsic image contrast because the emitted signals result from the specific biomolecular content of the tissue. Previous attempts to use MPM to image the murine irido-corneal region directly through the sclera have suffered from degradation in image resolution due to scattering of the focused laser light. As a result, transscleral MPM has limited ability to observe fine structures in the AOS. In this work, the porcine irido-corneal angle was successfully imaged through the transparent cornea using a gonioscopic lens to circumvent the highly scattering scleral tissue. The resulting high-resolution images allowed the detailed structures in the trabecular meshwork (TM) to be observed. Multimodal imaging by two-photon autofluorescence and second harmonic generation allowed visualization of different features in the TM without labels and without disruption of the TM or surrounding tissues. MPM gonioscopy is a promising noninvasive imaging tool for high-resolution studies of the AOS, and research continues to explore the potential for future clinical applications in humans.
Collapse
Affiliation(s)
- Omid Masihzadeh
- University of Colorado Denver, Department of Ophthalmology, 12800 East 19th Avenue Mailstop 8311, Aurora, Colorado 80045
| | - David A. Ammar
- University of Colorado Denver, Department of Ophthalmology, 12800 East 19th Avenue Mailstop 8311, Aurora, Colorado 80045
| | - Malik Y. Kahook
- University of Colorado Denver, Department of Ophthalmology, 1675 Aurora Court, F731 Aurora, Colorado 80045
| | - Emily A. Gibson
- University of Colorado Denver, Department of Bioengineering, 12700 East 19th Avenue Mailstop 8607, Aurora, Colorado 80045
| | - Tim C. Lei
- University of Colorado Denver, Department of Electrical Engineering, Campus Box 110, PO Box 173364, Denver, Colorado 80217-3364
- Address all correspondence to: Tim C. Lei, University of Colorado Denver, Department of Electrical Engineering, Campus Box 110, P.O. Box 173364, Denver, Colorado 80217-3364. Tel: 303-556-4924; Fax: 303-556-2383; E-mail:
| |
Collapse
|
48
|
Biela E, Galas J, Lee B, Johnson GL, Darzynkiewicz Z, Dobrucki JW. Col-F, a fluorescent probe for ex vivo confocal imaging of collagen and elastin in animal tissues. Cytometry A 2013; 83:533-9. [PMID: 23404939 DOI: 10.1002/cyto.a.22264] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 01/12/2013] [Accepted: 01/15/2013] [Indexed: 11/06/2022]
Abstract
A new low-molecular-weight fluorescent probe, Col-F, that exhibits affinity to collagen and elastin, was used successfully in imaging of extracellular matrix in freshly excised animal tissues. Col-F readily penetrates between live cells into tissues and binds to fibers of collagen and elastin by a noncovalent mechanism. Fibers of collagen and elastin have been stained in a variety of tissues, including tendon, skeletal muscle, connective tissue, and arteries. Cells migrating in a Col-F-stained collagenous biomaterial were also imaged. No phototoxic effects were detected when live keratocytes were imaged in the in vitro culture in the presence of Col-F. In conclusion, Col-F provides a simple and convenient tool for fluorescence three-dimensional imaging of intricate collagenous and elastic structures in live and fixed animal tissues, as well as in collagen-containing biomaterials.
Collapse
Affiliation(s)
- Ewa Biela
- Division of Cell Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | | | | | | | | | | |
Collapse
|
49
|
Kowalczuk L, Latour G, Bourges JL, Savoldelli M, Jeanny JC, Plamann K, Schanne-Klein MC, Behar-Cohen F. Multimodal Highlighting of Structural Abnormalities in Diabetic Rat and Human Corneas. Transl Vis Sci Technol 2013; 2:3. [PMID: 24049714 PMCID: PMC3763890 DOI: 10.1167/tvst.2.2.3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Accepted: 01/20/2013] [Indexed: 01/17/2023] Open
Abstract
PURPOSE This study aimed to highlight structural corneal changes in a model of type 2 diabetes, using in vivo corneal confocal microscopy (CCM). The abnormalities were also characterized by transmission electron microscopy (TEM) and second harmonic generation (SHG) microscopy in rat and human corneas. METHODS Goto-Kakizaki (GK) rats were observed at age 12 weeks (n = 3) and 1 year (n = 6), and compared to age-matched controls. After in vivo CCM examination, TEM and SHG microscopy were used to characterize the ultrastructure and the three-dimensional organization of the abnormalities. Human corneas from diabetic (n = 3) and nondiabetic (n = 3) patients were also included in the study. RESULTS In the basal epithelium of GK rats, CCM revealed focal hyper-reflective areas, and histology showed proliferative cells with irregular basement membrane. In the anterior stroma, extracellular matrix modifications were detected by CCM and confirmed in histology. In the Descemet's membrane periphery of all the diabetic corneas, hyper-reflective deposits were highlighted using CCM and characterized as long-spacing collagen fibrils by TEM. SHG microscopy revealed these deposits with high contrast, allowing specific detection in diabetic human and rat corneas without preparation and characterization of their three-dimensional organization. CONCLUSION Pathologic findings were observed early in the development of diabetes in GK rats. Similar abnormalities have been found in corneas from diabetic patients. TRANSLATIONAL RELEVANCE This multidisciplinary study highlights diabetes-induced corneal abnormalities in an animal model, but also in diabetic donors. This could constitute a potential early marker for diagnosis of hyperglycemia-induced tissue changes.
Collapse
Affiliation(s)
- Laura Kowalczuk
- Laboratory of Applied Optics, ENSTA ParisTech - École Polytechnique – CNRS, chemin de la Hunière, Palaiseau cedex, France
- INSERM UMRS 872, Team17, Physiopathology of ocular diseases, therapeutic innovations, 15 rue de l'école de médecine, Paris, France
- Pierre et Marie Curie University, Centre de Recherches des Cordeliers, 15 rue de l'école de médecine, Paris, France
- Sorbonne Paris Cité, Paris Descartes University, AP-HP Hôtel-Dieu Hospital, Department of Ophthalmology, 1 place du Parvis Notre-Dame, Paris, France
| | - Gaël Latour
- Laboratory for Optics and Biosciences, École Polytechnique – CNRS – INSERM U696, Palaiseau, France
| | - Jean-Louis Bourges
- INSERM UMRS 872, Team17, Physiopathology of ocular diseases, therapeutic innovations, 15 rue de l'école de médecine, Paris, France
- Pierre et Marie Curie University, Centre de Recherches des Cordeliers, 15 rue de l'école de médecine, Paris, France
- Sorbonne Paris Cité, Paris Descartes University, AP-HP Hôtel-Dieu Hospital, Department of Ophthalmology, 1 place du Parvis Notre-Dame, Paris, France
| | - Michèle Savoldelli
- Sorbonne Paris Cité, Paris Descartes University, AP-HP Hôtel-Dieu Hospital, Department of Ophthalmology, 1 place du Parvis Notre-Dame, Paris, France
| | - Jean-Claude Jeanny
- INSERM UMRS 872, Team17, Physiopathology of ocular diseases, therapeutic innovations, 15 rue de l'école de médecine, Paris, France
- Pierre et Marie Curie University, Centre de Recherches des Cordeliers, 15 rue de l'école de médecine, Paris, France
- Sorbonne Paris Cité, Paris Descartes University, AP-HP Hôtel-Dieu Hospital, Department of Ophthalmology, 1 place du Parvis Notre-Dame, Paris, France
| | - Karsten Plamann
- Laboratory of Applied Optics, ENSTA ParisTech - École Polytechnique – CNRS, chemin de la Hunière, Palaiseau cedex, France
| | | | - Francine Behar-Cohen
- INSERM UMRS 872, Team17, Physiopathology of ocular diseases, therapeutic innovations, 15 rue de l'école de médecine, Paris, France
- Pierre et Marie Curie University, Centre de Recherches des Cordeliers, 15 rue de l'école de médecine, Paris, France
- Sorbonne Paris Cité, Paris Descartes University, AP-HP Hôtel-Dieu Hospital, Department of Ophthalmology, 1 place du Parvis Notre-Dame, Paris, France
| |
Collapse
|
50
|
Latour G, Kowalczuk L, Savoldelli M, Bourges JL, Plamann K, Behar-Cohen F, Schanne-Klein MC. Hyperglycemia-induced abnormalities in rat and human corneas: the potential of second harmonic generation microscopy. PLoS One 2012; 7:e48388. [PMID: 23139780 PMCID: PMC3489670 DOI: 10.1371/journal.pone.0048388] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Accepted: 09/24/2012] [Indexed: 11/28/2022] Open
Abstract
Background Second Harmonic Generation (SHG) microscopy recently appeared as an efficient optical imaging technique to probe unstained collagen-rich tissues like cornea. Moreover, corneal remodeling occurs in many diseases and precise characterization requires overcoming the limitations of conventional techniques. In this work, we focus on diabetes, which affects hundreds of million people worldwide and most often leads to diabetic retinopathy, with no early diagnostic tool. This study then aims to establish the potential of SHG microscopy for in situ detection and characterization of hyperglycemia-induced abnormalities in the Descemet’s membrane, in the posterior cornea. Methodology/Principal Findings We studied corneas from age-matched control and Goto-Kakizaki rats, a spontaneous model of type 2 diabetes, and corneas from human donors with type 2 diabetes and without any diabetes. SHG imaging was compared to confocal microscopy, to histology characterization using conventional staining and transmitted light microscopy and to transmission electron microscopy. SHG imaging revealed collagen deposits in the Descemet’s membrane of unstained corneas in a unique way compared to these gold standard techniques in ophthalmology. It provided background-free images of the three-dimensional interwoven distribution of the collagen deposits, with improved contrast compared to confocal microscopy. It also provided structural capability in intact corneas because of its high specificity to fibrillar collagen, with substantially larger field of view than transmission electron microscopy. Moreover, in vivo SHG imaging was demonstrated in Goto-Kakizaki rats. Conclusions/Significance Our study shows unambiguously the high potential of SHG microscopy for three-dimensional characterization of structural abnormalities in unstained corneas. Furthermore, our demonstration of in vivo SHG imaging opens the way to long-term dynamical studies. This method should be easily generalized to other structural remodeling of the cornea and SHG microscopy should prove to be invaluable for in vivo corneal pathological studies.
Collapse
Affiliation(s)
- Gaël Latour
- Laboratory for Optics and Biosciences, École Polytechnique, CNRS, INSERM U696, Palaiseau, France
| | - Laura Kowalczuk
- Laboratory of Applied Optics, ENSTA ParisTech, École Polytechnique, CNRS, Palaiseau, France
- Team17: Physiopathology of Ocular Diseases, Therapeutic Innovations, INSERM UMRS 872, Paris, France
- Centre de Recherche des Cordeliers, Pierre et Marie Curie University, Paris, France
- Department of Ophthalmology, AP-HP Hôtel-Dieu, Paris Descartes University, Faculty of Medicine, Sorbonne Paris Cité, Paris, France
| | - Michèle Savoldelli
- Department of Ophthalmology, AP-HP Hôtel-Dieu, Paris Descartes University, Faculty of Medicine, Sorbonne Paris Cité, Paris, France
| | - Jean-Louis Bourges
- Department of Ophthalmology, AP-HP Hôtel-Dieu, Paris Descartes University, Faculty of Medicine, Sorbonne Paris Cité, Paris, France
| | - Karsten Plamann
- Laboratory of Applied Optics, ENSTA ParisTech, École Polytechnique, CNRS, Palaiseau, France
| | - Francine Behar-Cohen
- Team17: Physiopathology of Ocular Diseases, Therapeutic Innovations, INSERM UMRS 872, Paris, France
- Centre de Recherche des Cordeliers, Pierre et Marie Curie University, Paris, France
- Department of Ophthalmology, AP-HP Hôtel-Dieu, Paris Descartes University, Faculty of Medicine, Sorbonne Paris Cité, Paris, France
| | - Marie-Claire Schanne-Klein
- Laboratory for Optics and Biosciences, École Polytechnique, CNRS, INSERM U696, Palaiseau, France
- * E-mail:
| |
Collapse
|