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Filan C, Charles S, Casteleiro Costa P, Niu W, Cheng BF, Wen Z, Lu H, Robles FE. Non-Invasive Label-free Analysis Pipeline for In Situ Characterization of Differentiation in 3D Brain Organoid Models. RESEARCH SQUARE 2024:rs.3.rs-4049577. [PMID: 38645145 PMCID: PMC11030508 DOI: 10.21203/rs.3.rs-4049577/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
Brain organoids provide a unique opportunity to model organ development in a system similar to human organogenesis in vivo. Brain organoids thus hold great promise for drug screening and disease modeling. Conventional approaches to organoid characterization predominantly rely on molecular analysis methods, which are expensive, time-consuming, labor-intensive, and involve the destruction of the valuable 3D architecture of the organoids. This reliance on end-point assays makes it challenging to assess cellular and subcellular events occurring during organoid development in their 3D context. As a result, the long developmental processes are not monitored nor assessed. The ability to perform non-invasive assays is critical for longitudinally assessing features of organoid development during culture. In this paper, we demonstrate a label-free high-content imaging approach for observing changes in organoid morphology and structural changes occurring at the cellular and subcellular level. Enabled by microfluidic-based culture of 3D cell systems and a novel 3D quantitative phase imaging method, we demonstrate the ability to perform non-destructive high-resolution imaging of the organoid. The highlighted results demonstrated in this paper provide a new approach to performing live, non-destructive monitoring of organoid systems during culture.
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Affiliation(s)
- Caroline Filan
- Georgia Institute of Technology, George W. Woodruff School of Mechanical Engineering, Atlanta, GA, 30318, USA
| | - Seleipiri Charles
- Georgia Institute of Technology, Interdisciplinary Program in Bioengineering, Atlanta, GA, 30332, USA
| | - Paloma Casteleiro Costa
- Georgia Institute of Technology, School of Electrical & Computer Engineering, Atlanta, GA, 30332, USA
| | - Weibo Niu
- Emory University School of Medicine, Department of Psychiatry and Behavioral Sciences, Atlanta, Georgia 30322, USA
| | - Brian F. Cheng
- Georgia Institute of Technology and Emory University, Wallace H. Coulter Department of Biomedical Engineering, Atlanta, GA, 30318, USA
| | - Zhexing Wen
- Emory University School of Medicine, Department of Psychiatry and Behavioral Sciences, Atlanta, Georgia 30322, USA
- Emory University School of Medicine, Departments of Cell Biology and Neurology, Atlanta, Georgia, 30322, USA
| | - Hang Lu
- Georgia Institute of Technology, Interdisciplinary Program in Bioengineering, Atlanta, GA, 30332, USA
- Georgia Institute of Technology, School of Chemical & Biomolecular Engineering, Atlanta, Georgia 30332, USA
| | - Francisco E. Robles
- Georgia Institute of Technology, George W. Woodruff School of Mechanical Engineering, Atlanta, GA, 30318, USA
- Georgia Institute of Technology, Interdisciplinary Program in Bioengineering, Atlanta, GA, 30332, USA
- Georgia Institute of Technology, School of Electrical & Computer Engineering, Atlanta, GA, 30332, USA
- Georgia Institute of Technology and Emory University, Wallace H. Coulter Department of Biomedical Engineering, Atlanta, GA, 30318, USA
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2
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Wakamatsu K, Ito S. Recent Advances in Characterization of Melanin Pigments in Biological Samples. Int J Mol Sci 2023; 24:ijms24098305. [PMID: 37176019 PMCID: PMC10179066 DOI: 10.3390/ijms24098305] [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: 04/08/2023] [Revised: 04/23/2023] [Accepted: 04/28/2023] [Indexed: 05/15/2023] Open
Abstract
The melanin pigments eumelanin (EM) and pheomelanin (PM), which are dark brown to black and yellow to reddish-brown, respectively, are widely found among vertebrates. They are produced in melanocytes in the epidermis, hair follicles, the choroid, the iris, the inner ear, and other tissues. The diversity of colors in animals is mainly caused by the quantity and quality of their melanin, such as by the ratios of EM versus PM. We have developed micro-analytical methods to simultaneously measure EM and PM and used these to study the biochemical and genetic fundamentals of pigmentation. The photoreactivity of melanin has become a major focus of research because of the postulated relevance of EM and PM for the risk of UVA-induced melanoma. Our biochemical methods have found application in many clinical studies on genetic conditions associated with alterations in pigmentation. Recently, besides chemical degradative methods, other methods have been developed for the characterization of melanin, and these are also discussed here.
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Affiliation(s)
- Kazumasa Wakamatsu
- Institute for Melanin Chemistry, Fujita Health University, Toyoake 470-192, Aichi, Japan
| | - Shosuke Ito
- Institute for Melanin Chemistry, Fujita Health University, Toyoake 470-192, Aichi, Japan
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3
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Optical characteristics of the skin with dark circles using pump-probe imaging. Sci Rep 2022; 12:18553. [PMID: 36329126 PMCID: PMC9633781 DOI: 10.1038/s41598-022-21131-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 09/22/2022] [Indexed: 11/06/2022] Open
Abstract
Pump-probe imaging was first used for quantitative analysis of melanin in dark circles' skin to improve the ability to diagnose and treat dark circles on human skin. This study aimed to compare the distribution characteristics in melanin of lower eyelid skin tissues and to determine whether pump-probe imaging has potential for the classification of dark circles in vivo. Specimens obtained from 15 patients undergoing blepharoplasty were examined using pump-probe imaging. Furthermore, adjacent slices were respectively treated with hematoxylin-eosin (HE) and ferrous sulfate (FeSO4) staining for cross-references. Subsequently, the melanin content index (MCI) and mean fluorescence intensity (MFI) were quantitatively analyzed by the pump-probe imaging. The distribution of melanin granules in the pump-probe image and FeSO4 staining was consistent. Meanwhile, the tissues of the skin with dark circles and normal skin demonstrated significant differences in MCI and MFI. These differences can be used to distinguish the skin with dark circles from the normal skin. Pump-probe imaging could be used for the analysis of the microstructure and spectral characteristics of melanin granules in skin with dark circles. Significant differences were noted between the pigmented type of dark circles and the other two groups (normal skin and the vascular type of dark circles), while no significant differences were found between normal skin and the vascular type of dark circles.
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Grass D, Beasley GM, Fischer MC, Selim MA, Zhou Y, Warren WS. Contrast mechanisms in pump-probe microscopy of melanin. OPTICS EXPRESS 2022; 30:31852-31862. [PMID: 36242259 PMCID: PMC9576283 DOI: 10.1364/oe.469506] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/04/2022] [Accepted: 08/05/2022] [Indexed: 05/27/2023]
Abstract
Pump-probe microscopy of melanin in tumors has been proposed to improve diagnosis of malignant melanoma, based on the hypothesis that aggressive cancers disaggregate melanin structure. However, measured signals of melanin are complex superpositions of multiple nonlinear processes, which makes interpretation challenging. Polarization control during measurement and data fitting are used to decompose signals of melanin into their underlying molecular mechanisms. We then identify the molecular mechanisms that are most susceptible to melanin disaggregation and derive false-coloring schemes to highlight these processes in biological tissue. We demonstrate that false-colored images of a small set of melanoma tumors correlate with clinical concern. More generally, our systematic approach of decomposing pump-probe signals can be applied to a multitude of different samples.
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Affiliation(s)
- David Grass
- Department of Chemistry,
Duke University, Durham, North Carolina, USA
| | - Georgia M. Beasley
- Department of Surgery, Duke University, Durham, North Carolina, USA
- Duke Cancer Institute, Duke University, Durham, North Carolina, USA
- Department of Medicine, Duke University, Durham, North Carolina, USA
| | - Martin C. Fischer
- Department of Chemistry,
Duke University, Durham, North Carolina, USA
- Department of Physics, Duke University, Durham, North Carolina, USA
| | - M. Angelica Selim
- Department of Pathology, Duke University, Durham, North Carolina, USA
| | - Yue Zhou
- Department of Chemistry,
Duke University, Durham, North Carolina, USA
| | - Warren S. Warren
- Department of Chemistry,
Duke University, Durham, North Carolina, USA
- Duke Cancer Institute, Duke University, Durham, North Carolina, USA
- Department of Physics, Duke University, Durham, North Carolina, USA
- Department of Biomedical Engineering, Duke University, Durham, North Carolina, USA
- Department of Radiology, Duke University, Durham, North Carolina, USA
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5
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Prostate cancer histopathology using label-free multispectral deep-UV microscopy quantifies phenotypes of tumor aggressiveness and enables multiple diagnostic virtual stains. Sci Rep 2022; 12:9329. [PMID: 35665770 PMCID: PMC9167293 DOI: 10.1038/s41598-022-13332-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 05/23/2022] [Indexed: 12/20/2022] Open
Abstract
Identifying prostate cancer patients that are harboring aggressive forms of prostate cancer remains a significant clinical challenge. Here we develop an approach based on multispectral deep-ultraviolet (UV) microscopy that provides novel quantitative insight into the aggressiveness and grade of this disease, thus providing a new tool to help address this important challenge. We find that UV spectral signatures from endogenous molecules give rise to a phenotypical continuum that provides unique structural insight (i.e., molecular maps or “optical stains") of thin tissue sections with subcellular (nanoscale) resolution. We show that this phenotypical continuum can also be applied as a surrogate biomarker of prostate cancer malignancy, where patients with the most aggressive tumors show a ubiquitous glandular phenotypical shift. In addition to providing several novel “optical stains” with contrast for disease, we also adapt a two-part Cycle-consistent Generative Adversarial Network to translate the label-free deep-UV images into virtual hematoxylin and eosin (H&E) stained images, thus providing multiple stains (including the gold-standard H&E) from the same unlabeled specimen. Agreement between the virtual H&E images and the H&E-stained tissue sections is evaluated by a panel of pathologists who find that the two modalities are in excellent agreement. This work has significant implications towards improving our ability to objectively quantify prostate cancer grade and aggressiveness, thus improving the management and clinical outcomes of prostate cancer patients. This same approach can also be applied broadly in other tumor types to achieve low-cost, stain-free, quantitative histopathological analysis.
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Lee HJ, Chen Z, Collard M, Chen F, Chen JG, Wu M, Alani RM, Cheng JX. Multimodal Metabolic Imaging Reveals Pigment Reduction and Lipid Accumulation in Metastatic Melanoma. BME FRONTIERS 2021; 2021:9860123. [PMID: 37849907 PMCID: PMC10521760 DOI: 10.34133/2021/9860123] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Accepted: 08/30/2021] [Indexed: 10/19/2023] Open
Abstract
Objective and Impact Statement. Molecular signatures are needed for early diagnosis and improved treatment of metastatic melanoma. By high-resolution multimodal chemical imaging of human melanoma samples, we identify a metabolic reprogramming from pigmentation to lipid droplet (LD) accumulation in metastatic melanoma. Introduction. Metabolic plasticity promotes cancer survival and metastasis, which promises to serve as a prognostic marker and/or therapeutic target. However, identifying metabolic alterations has been challenged by difficulties in mapping localized metabolites with high spatial resolution. Methods. We developed a multimodal stimulated Raman scattering and pump-probe imaging platform. By time-domain measurement and phasor analysis, our platform allows simultaneous mapping of lipids and pigments at a subcellular level. Furthermore, we identify the sources of these metabolic signatures by tracking deuterium metabolites at a subcellular level. By validation with mass spectrometry, a specific fatty acid desaturase pathway was identified. Results. We identified metabolic reprogramming from a pigment-containing phenotype in low-grade melanoma to an LD-rich phenotype in metastatic melanoma. The LDs contain high levels of cholesteryl ester and unsaturated fatty acids. Elevated fatty acid uptake, but not de novo lipogenesis, contributes to the LD-rich phenotype. Monounsaturated sapienate, mediated by FADS2, is identified as an essential fatty acid that promotes cancer migration. Blocking such metabolic signatures effectively suppresses the migration capacity both in vitro and in vivo. Conclusion. By multimodal spectroscopic imaging and lipidomic analysis, the current study reveals lipid accumulation, mediated by fatty acid uptake, as a metabolic signature that can be harnessed for early diagnosis and improved treatment of metastatic melanoma.
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Affiliation(s)
- Hyeon Jeong Lee
- Photonics Center, Department of Electrical and Computer Engineering, Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Zhicong Chen
- Photonics Center, Department of Electrical and Computer Engineering, Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Marianne Collard
- Department of Dermatology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Fukai Chen
- Photonics Center, Department of Electrical and Computer Engineering, Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Jiaji G. Chen
- Department of Dermatology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Muzhou Wu
- Department of Dermatology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Rhoda M. Alani
- Department of Dermatology, Boston University School of Medicine, Boston, MA 02118, USA
| | - Ji-Xin Cheng
- Photonics Center, Department of Electrical and Computer Engineering, Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
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7
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Costa PC, Guang Z, Ledwig P, Zhang Z, Neill S, Olson JJ, Robles FE. Towards in-vivo label-free detection of brain tumor margins with epi-illumination tomographic quantitative phase imaging. BIOMEDICAL OPTICS EXPRESS 2021; 12:1621-1634. [PMID: 33796377 PMCID: PMC7984798 DOI: 10.1364/boe.416731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 02/11/2021] [Accepted: 02/20/2021] [Indexed: 05/03/2023]
Abstract
Brain tumor surgery involves a delicate balance between maximizing the extent of tumor resection while minimizing damage to healthy brain tissue that is vital for neurological function. However, differentiating between tumor, particularly infiltrative disease, and healthy brain in-vivo remains a significant clinical challenge. Here we demonstrate that quantitative oblique back illumination microscopy (qOBM)-a novel label-free optical imaging technique that achieves tomographic quantitative phase imaging in thick scattering samples-clearly differentiates between healthy brain tissue and tumor, including infiltrative disease. Data from a bulk and infiltrative brain tumor animal model show that qOBM enables quantitative phase imaging of thick fresh brain tissues with remarkable cellular and subcellular detail that closely resembles histopathology using hematoxylin and eosin (H&E) stained fixed tissue sections, the gold standard for cancer detection. Quantitative biophysical features are also extracted from qOBM which yield robust surrogate biomarkers of disease that enable (1) automated tumor and margin detection with high sensitivity and specificity and (2) facile visualization of tumor regions. Finally, we develop a low-cost, flexible, fiber-based handheld qOBM device which brings this technology one step closer to in-vivo clinical use. This work has significant implications for guiding neurosurgery by paving the way for a tool that delivers real-time, label-free, in-vivo brain tumor margin detection.
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Affiliation(s)
- Paloma Casteleiro Costa
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Zhe Guang
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332, USA
| | - Patrick Ledwig
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332, USA
| | - Zhaobin Zhang
- Winship Cancer Institute, Emory University, Atlanta, GA 30322, USA
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Stewart Neill
- Winship Cancer Institute, Emory University, Atlanta, GA 30322, USA
- Department of Pathology & Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Jeffrey J. Olson
- Winship Cancer Institute, Emory University, Atlanta, GA 30322, USA
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Francisco E. Robles
- School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332, USA
- Winship Cancer Institute, Emory University, Atlanta, GA 30322, USA
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8
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Yakimov BP, Shirshin EA, Schleusener J, Allenova AS, Fadeev VV, Darvin ME. Melanin distribution from the dermal-epidermal junction to the stratum corneum: non-invasive in vivo assessment by fluorescence and Raman microspectroscopy. Sci Rep 2020; 10:14374. [PMID: 32873804 PMCID: PMC7463016 DOI: 10.1038/s41598-020-71220-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 08/11/2020] [Indexed: 12/11/2022] Open
Abstract
The fate of melanin in the epidermis is of great interest due to its involvement in numerous physiological and pathological processes in the skin. Melanin localization can be assessed ex vivo and in vivo using its distinctive optical properties. Melanin exhibits a characteristic Raman spectrum band shape and discernible near-infrared excited (NIR) fluorescence. However, a detailed analysis of the capabilities of depth-resolved confocal Raman and fluorescence microspectroscopy in the evaluation of melanin distribution in the human skin is lacking. Here we demonstrate how the fraction of melanin at different depths in the human skin in vivo can be estimated from its Raman spectra (bands at 1,380 and 1,570 cm-1) using several procedures including a simple ratiometric approach, spectral decomposition and non-negative matrix factorization. The depth profiles of matrix factorization components specific to melanin, collagen and natural moisturizing factor provide information about their localization in the skin. The depth profile of the collagen-related matrix factorization component allows for precise determination of the dermal-epidermal junction, i.e. the epidermal thickness. Spectral features of fluorescence background originating from melanin were found to correlate with relative intensities of the melanin Raman bands. We also hypothesized that NIR fluorescence in the skin is not originated solely from melanin, and the possible impact of oxidized species should be taken into account. The ratio of melanin-related Raman bands at 1,380 and 1,570 cm-1 could be related to melanin molecular organization. The proposed combined analysis of the Raman scattering signal and NIR fluorescence could be a useful tool for rapid non-invasive in vivo diagnostics of melanin-related processes in the human skin.
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Affiliation(s)
- B P Yakimov
- Faculty of Physics, M.V. Lomonosov Moscow State University, 1-2 Leninskie Gory, Moscow, Russia, 119991
- Medical Research and Education Center, M.V. Lomonosov Moscow State University, Lomonosovsky Prospect 27/10, Moscow, Russia, 119991
- Institute for Regenerative Medicine, Sechenov First Moscow State Medical University, Trubetskaya 8-2, Moscow, Russia, 119991
| | - E A Shirshin
- Faculty of Physics, M.V. Lomonosov Moscow State University, 1-2 Leninskie Gory, Moscow, Russia, 119991.
- Institute for Regenerative Medicine, Sechenov First Moscow State Medical University, Trubetskaya 8-2, Moscow, Russia, 119991.
- Institute of Spectroscopy of the Russian Academy of Sciences, Fizicheskaya Str., 5, 108840, Troitsk, Moscow, Russia.
| | - J Schleusener
- Department of Dermatology, Venerology and Allergology, Center of Experimental and Applied Cutaneous Physiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany
| | - A S Allenova
- Medical Research and Education Center, M.V. Lomonosov Moscow State University, Lomonosovsky Prospect 27/10, Moscow, Russia, 119991
- Division of Immune-Mediated Skin Diseases, Sechenov First Moscow State Medical University, Trubetskaya 8-2, Moscow, Russia, 119991
| | - V V Fadeev
- Faculty of Physics, M.V. Lomonosov Moscow State University, 1-2 Leninskie Gory, Moscow, Russia, 119991
| | - M E Darvin
- Department of Dermatology, Venerology and Allergology, Center of Experimental and Applied Cutaneous Physiology, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany.
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9
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Zhu Y, Cheng JX. Transient absorption microscopy: Technological innovations and applications in materials science and life science. J Chem Phys 2020; 152:020901. [PMID: 31941290 PMCID: PMC7195865 DOI: 10.1063/1.5129123] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 12/15/2019] [Indexed: 01/08/2023] Open
Abstract
Transient absorption (TA) spectroscopy has been extensively used in the study of excited state dynamics of various materials and molecules. The transition from TA spectroscopy to TA microscopy, which enables the space-resolved measurement of TA, is opening new investigations toward a more complete picture of excited state dynamics in functional materials, as well as the mapping of crucial biopigments for precision diagnosis. Here, we review the recent instrumental advancement that is pushing the limit of spatial resolution, detection sensitivity, and imaging speed. We further highlight the emerging application in materials science and life science.
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Affiliation(s)
- Yifan Zhu
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, USA
| | - Ji-Xin Cheng
- Department of Chemistry, Boston University, Boston, Massachusetts 02215, USA
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10
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Robles FE, Deb S, Vajzovic L, Vora GK, Mruthyunjaya P, Warren WS. Analysis of Melanin Structure and Biochemical Composition in Conjunctival Melanocytic Lesions Using Pump-Probe Microscopy. Transl Vis Sci Technol 2019; 8:33. [PMID: 31183249 PMCID: PMC6549561 DOI: 10.1167/tvst.8.3.33] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 04/15/2019] [Indexed: 01/15/2023] Open
Abstract
Purpose We analyze melanin structure and biochemical composition in conjunctival melanocytic lesions using pump-probe microscopy to assess the potential for this method to assist in melanoma diagnosis. Methods Pump-probe microscopy interrogates transient excited-state photodynamic properties of absorbing molecules, which yields highly specific molecular information with subcellular spatial resolution. This method is applied to analyze melanin in 39 unstained, thin biopsy specimens of melanocytic conjunctival lesions. Quantitative features of the biochemical composition and structure of melanin in histopathologic specimens are assessed using a geometric representation of principal component analysis (PCA) and principles of mathematical morphology. Diagnostic power is determined using a feature selection algorithm combined with cross validation. Results Conjunctival melanomas show higher biochemical heterogeneity and different overall biochemical composition than primary acquired melanosis of the conjunctiva (PAM) without severe atypia. The molecular signatures of PAMs with severe atypia more closely resemble melanomas than other types of PAMs. Pigment organization in the tissue becomes more disorganized as diagnosis of the lesions worsen, but nevi are more inconsistent biochemically and structurally than other lesions. Relatively high sensitivity (SE) and specificity (SP) is achieved for differentiating between various melanocytic lesions, particularly PAMs without severe atypia and melanomas (SE = 89%; SP = 87%). Conclusions Pump-probe microscopy is a powerful tool that can identify quantitative, phenotypic differences between various types of conjunctival melanocytic lesions. Translational Relevance This study further validates the use of pump-probe microscopy as a potential diagnostic aid for histopathologic evaluation of conjunctival melanocytic lesions.
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Affiliation(s)
- Francisco E Robles
- Department of Chemistry, Duke University, Durham, NC, USA.,Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Sanghamitra Deb
- Department of Chemistry, Duke University, Durham, NC, USA.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Lejla Vajzovic
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA
| | - Gargi K Vora
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA
| | - Prithvi Mruthyunjaya
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA.,Department of Ophthalmology, Stanford University Medical Center, Palo Alto, CA, USA
| | - Warren S Warren
- Department of Chemistry, Duke University, Durham, NC, USA.,Department of Radiology, Duke University Medical Center, Durham, NC, USA.,Duke University, Departments of Physics, Durham, NC, USA
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11
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Ju KY, Degan S, Fischer MC, Zhou KC, Jia X, Yu J, Warren WS. Unraveling the molecular nature of melanin changes in metastatic cancer. JOURNAL OF BIOMEDICAL OPTICS 2019; 24:1-13. [PMID: 30977334 PMCID: PMC6460485 DOI: 10.1117/1.jbo.24.5.051414] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 03/11/2019] [Indexed: 05/27/2023]
Abstract
More people die from melanoma after a stage I diagnosis than after a stage IV diagnosis, because the tools available to clinicians do not readily identify which early-stage cancers will be aggressive. Near-infrared pump-probe microscopy detects fundamental differences in melanin structure between benign human moles and melanoma and also correlates with metastatic potential. However, the biological mechanisms of these changes have been difficult to quantify, as many different mechanisms can contribute to the pump-probe signal. We use model systems (sepia, squid, and synthetic eumelanin), cellular uptake studies, and a range of pump and probe wavelengths to demonstrate that the clinically observed effects come from alterations of the aggregated mode from "thick oligomer stacks" to "thin oligomer stacks" (due to changes in monomer composition) and (predominantly) deaggregation of the assembled melanin structure. This provides the opportunity to use pump-probe microscopy for the detection and study of melanin-associated diseases.
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Affiliation(s)
- Kuk-Youn Ju
- Duke University, Department of Chemistry, Durham, North Carolina, United States
| | - Simone Degan
- Duke University, Department of Chemistry, Durham, North Carolina, United States
- Duke University, Department of Radiology, Durham, North Carolina, United States
| | - Martin C. Fischer
- Duke University, Department of Chemistry, Durham, North Carolina, United States
- Duke University, Department of Physics, Durham, North Carolina, United States
| | - Kevin C. Zhou
- Duke University, Department of Biomedical Engineering, Durham, North Carolina, United States
| | - Xiaomeng Jia
- Duke University, Department of Physics, Durham, North Carolina, United States
| | - Jin Yu
- Duke University, Department of Chemistry, Durham, North Carolina, United States
| | - Warren S. Warren
- Duke University, Department of Chemistry, Durham, North Carolina, United States
- Duke University, Department of Radiology, Durham, North Carolina, United States
- Duke University, Department of Physics, Durham, North Carolina, United States
- Duke University, Department of Biomedical Engineering, Durham, North Carolina, United States
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12
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Ju KY, Fischer MC, Warren WS. Understanding the Role of Aggregation in the Broad Absorption Bands of Eumelanin. ACS NANO 2018; 12:12050-12061. [PMID: 30500158 DOI: 10.1021/acsnano.8b04905] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In this work, we investigate the relationship between the complex hierarchical assembly structure of eumelanin, its characteristic broad absorption band, and the highly unusual nonlinear dynamics revealed by pump-probe or transient absorption microscopy. Melanin-like nanoparticles (MelNPs), generated by spontaneous oxidation of dopamine, were created with uniform but adjustable size distributions, and kinetically controlled oxidation was probed with a wide range of characterization methods. This lets us explore the broad absorption bands of eumelanin models at different assembly levels, such as small subunit fractions (single monomeric and oligomeric units and small oligomer stacks), stacked oligomer fractions (protomolecules), and large-scale aggregates of protomolecules (parental particles). Both the absorption and pump-probe dynamics are very sensitive to these structural differences or to the size of intact particles (a surprising result for an organic polymer). We show that the geometric packing order of protomolecules in long-range aggregation is key secondary interactions to extend the absorption band of eumelanin to the low energy spectrum and produce drastic changes in the transient absorption spectrum.
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Affiliation(s)
- Kuk-Youn Ju
- Department of Chemistry , Duke University , Durham , North Carolina 27708 , United States
| | - Martin C Fischer
- Department of Chemistry , Duke University , Durham , North Carolina 27708 , United States
- Department of Physics , Duke University , Durham , North Carolina 27708 , United States
| | - Warren S Warren
- Department of Chemistry , Duke University , Durham , North Carolina 27708 , United States
- Department of Physics , Duke University , Durham , North Carolina 27708 , United States
- Department of Radiology , Duke University , Durham , North Carolina 27710 , United States
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Evans CL. Nonlinear Optical Microscopy for Melanoma: Challenges, Tools and Opportunities. Photochem Photobiol 2018; 94:624-632. [PMID: 29485199 DOI: 10.1111/php.12916] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 02/17/2018] [Indexed: 02/02/2023]
Abstract
The natural pigments known as melanins are thought to play a role in the etiology and progression of melanoma, but many of their roles are currently not well understood. While quantification of melanins have, up until now, have been performed in bulk tissue ex vivo, new imaging technologies have unlocked the means to visualize and quantify melanins at the sub-cellular scale. The nonlinear imaging methods known as pump-probe, coherent Raman, and sum-frequency absorption microscopies provide subcellular resolution imaging of melanins, enabling label-free, longitudinal quantification of both eumelanin and pheomelanin in situ and in vivo. These nonlinear imaging toolkits have been well proven in both animal models and human samples, moving them tantalizingly close to clinical application. Future efforts integrating these tools into practical, mobile imaging systems will provide immense benefit both to clinical research and practice.
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Affiliation(s)
- Conor L Evans
- Wellman Center for Photomedicine, Harvard Medical School, Massachusetts General Hospital, Charlestown, MA
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Puza CJ, Warren WS, Mosca PJ. The changing landscape of dermatology practice: melanoma and pump-probe laser microscopy. Lasers Med Sci 2017; 32:1935-1939. [PMID: 28890988 DOI: 10.1007/s10103-017-2319-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 08/28/2017] [Indexed: 12/28/2022]
Abstract
To present current melanoma diagnosis, staging, prognosis, and treatment algorithms and how recent advances in laser pump-probe microscopy will fill in the gaps in our clinical understanding. Expert opinion and significantly cited articles identified in SCOPUS were used in conjunction with a pubmed database search on Melanoma practice guidelines from the last 10 years. Significant advances in melanoma treatment have been made over the last decade. However, proper treatment algorithm and prognostic information per melanoma stage remain controversial. The next step for providers will involve the identification of patient population(s) that can benefit from recent advances. One method of identifying potential patients is through new laser imaging techniques. Pump-probe laser microscopy has been shown to correctly identify nevi from melanoma and furthermore stratify melanoma by aggressiveness. The recent development of effective adjuvant therapies for melanoma is promising and should be utilized on appropriate patient populations that can potentially be identified using pump-probe laser microscopy.
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Affiliation(s)
| | | | - Paul J Mosca
- Duke University, Department of Surgery, Durham, NC, USA
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15
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Wilson JW, Robles FE, Deb S, Warren WS, Fischer MC. Comparison of pump-probe and hyperspectral imaging in unstained histology sections of pigmented lesions. BIOMEDICAL OPTICS EXPRESS 2017; 8:3882-3890. [PMID: 28856057 PMCID: PMC5560848 DOI: 10.1364/boe.8.003882] [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: 06/09/2017] [Revised: 07/25/2017] [Accepted: 07/25/2017] [Indexed: 05/06/2023]
Abstract
Microscopic variations in melanin composition can be mapped through linear and nonlinear optical responses. Though instrumentation to measure linear attenuation is simple and inexpensive, the nonlinear response provides more degrees of freedom with which to spectroscopically resolve pigments. The objective of this study is to assess differences in imaging melanin contrast by comparing hyperspectral (linear) versus pump-probe (nonlinear) microscopy of unstained histology sections of pigmented lesions. The images and analysis we have presented here show that pump-probe uncovers a greater variation in pigment composition, compared with hyperspectral microscopy, and that the two methods yield complimentary biochemical information.
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Affiliation(s)
- Jesse W. Wilson
- Duke University, Department of Chemistry, Durham, NC, 27708, USA
- Currently with Colorado State University, Department of Electrical Engineering and School of Biomedical Engineering, Fort Collins, CO, 80523, USA
| | - Francisco E. Robles
- Duke University, Department of Chemistry, Durham, NC, 27708, USA
- Currently with Georgia Institute of Technology and Emory University, Wallace H Coulter Department of Biomedical Engineering, Atlanta, GA, 30332, USA
| | - Sanghamitra Deb
- Duke University, Department of Chemistry, Durham, NC, 27708, USA
- Currently with University of Illinois at Urbana-Champaign, Beckman Institute for Advanced Science and Technology, Urbana, IL, 61801, USA
| | - Warren S. Warren
- Duke University, Department of Chemistry, Durham, NC, 27708, USA
- Duke University, Departments of Physics, Biomedical Engineering, and Radiology, Durham, NC, 27708, USA
| | - Martin C. Fischer
- Duke University, Department of Chemistry, Durham, NC, 27708, USA
- Duke University, Departments of Physics, Biomedical Engineering, and Radiology, Durham, NC, 27708, USA
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Label-Free Imaging of Female Genital Tract Melanocytic Lesions With Pump-Probe Microscopy: A Promising Diagnostic Tool. J Low Genit Tract Dis 2017; 21:137-144. [PMID: 28157824 PMCID: PMC5365357 DOI: 10.1097/lgt.0000000000000290] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We analyze vulvar melanomas using an emerging optical molecular imaging technique called pump-probe microscopy. The method may improve the diagnosis and staging of vulvar melanomas. Supplemental digital content is available in the text. Objectives Melanomas of the female genital tract present a unique clinical challenge. Not only are these lesions in an anatomically sensitive area, but also they tend to be multifocal and have high recurrence rates. Furthermore, several benign melanocytic proliferations resemble early-stage melanoma clinically and/or histopathologically. Thus, there is a significant need for additional tools that can help correctly diagnose and stage these lesions. Here, we quantitatively and nondestructively analyze the chemical composition of melanin in excised pigmented lesions of the female genital tract using pump-probe microscopy, a high-resolution optical imaging technique that is sensitive to many biochemical properties of melanin. Materials and Methods Thirty-one thin (~5 μm) tissue sections previously excised from female genital tract melanocytic lesions were imaged with pump-probe microscopy and analyzed. Results We find significant quantitative differences in melanin type and structure between melanoma and nonmalignant melanocytic proliferations. Our analysis also suggests a link between the molecular signatures of melanins and lesion-specific genetic mutations. Finally, significant differences are found between metastatic and nonmetastatic melanomas. The limitations of this work include the fact that molecular information is restricted to melanin pigment and the sample size is relatively small. Conclusions Pump-probe microscopy provides unique information regarding the biochemical composition of genital tract melanocytic lesions, which can be used to improve the diagnosis and staging of vulvar melanomas.
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17
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Audier X, Balla N, Rigneault H. Pump-probe micro-spectroscopy by means of an ultra-fast acousto-optics delay line. OPTICS LETTERS 2017; 42:294-297. [PMID: 28081096 DOI: 10.1364/ol.42.000294] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We demonstrate femtosecond pump-probe transient absorption spectroscopy using a programmable dispersive filter as an ultra-fast delay line. Combined with fast synchronous detection, this delay line allows for recording of 6 ps decay traces at 34 kHz. With such acquisition speed, we perform single point pump-probe spectroscopy on bulk samples in 80 μs and hyperspectral pump-probe imaging over a field of view of 100 μm in less than a second. The usability of the method is illustrated in a showcase experiment to image and discriminate between two pigments in a mixture.
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Thompson A, Robles FE, Wilson JW, Deb S, Calderbank R, Warren WS. Dual-wavelength pump-probe microscopy analysis of melanin composition. Sci Rep 2016; 6:36871. [PMID: 27833147 PMCID: PMC5104978 DOI: 10.1038/srep36871] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 10/21/2016] [Indexed: 11/08/2022] Open
Abstract
Pump-probe microscopy is an emerging technique that provides detailed chemical information of absorbers with sub-micrometer spatial resolution. Recent work has shown that the pump-probe signals from melanin in human skin cancers correlate well with clinical concern, but it has been difficult to infer the molecular origins of these differences. Here we develop a mathematical framework to describe the pump-probe dynamics of melanin in human pigmented tissue samples, which treats the ensemble of individual chromophores that make up melanin as Gaussian absorbers with bandwidth related via Frenkel excitons. Thus, observed signals result from an interplay between the spectral bandwidths of the individual underlying chromophores and spectral proximity of the pump and probe wavelengths. The model is tested using a dual-wavelength pump-probe approach and a novel signal processing method based on gnomonic projections. Results show signals can be described by a single linear transition path with different rates of progress for different individual pump-probe wavelength pairs. Moreover, the combined dual-wavelength data shows a nonlinear transition that supports our mathematical framework and the excitonic model to describe the optical properties of melanin. The novel gnomonic projection analysis can also be an attractive generic tool for analyzing mixing paths in biomolecular and analytical chemistry.
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Affiliation(s)
- Andrew Thompson
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
| | | | - Jesse W. Wilson
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
| | - Sanghamitra Deb
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
| | - Robert Calderbank
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Warren S. Warren
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
- Department of Physics, Duke University, Durham, North Carolina 27708, USA
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Fischer MC, Wilson JW, Robles FE, Warren WS. Invited Review Article: Pump-probe microscopy. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:031101. [PMID: 27036751 PMCID: PMC4798998 DOI: 10.1063/1.4943211] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 02/07/2016] [Indexed: 05/17/2023]
Abstract
Multiphoton microscopy has rapidly gained popularity in biomedical imaging and materials science because of its ability to provide three-dimensional images at high spatial and temporal resolution even in optically scattering environments. Currently the majority of commercial and home-built devices are based on two-photon fluorescence and harmonic generation contrast. These two contrast mechanisms are relatively easy to measure but can access only a limited range of endogenous targets. Recent developments in fast laser pulse generation, pulse shaping, and detection technology have made accessible a wide range of optical contrasts that utilize multiple pulses of different colors. Molecular excitation with multiple pulses offers a large number of adjustable parameters. For example, in two-pulse pump-probe microscopy, one can vary the wavelength of each excitation pulse, the detection wavelength, the timing between the excitation pulses, and the detection gating window after excitation. Such a large parameter space can provide much greater molecular specificity than existing single-color techniques and allow for structural and functional imaging without the need for exogenous dyes and labels, which might interfere with the system under study. In this review, we provide a tutorial overview, covering principles of pump-probe microscopy and experimental setup, challenges associated with signal detection and data processing, and an overview of applications.
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Affiliation(s)
- Martin C Fischer
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
| | - Jesse W Wilson
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
| | - Francisco E Robles
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
| | - Warren S Warren
- Departments of Chemistry, Biomedical Engineering, Physics, and Radiology, Duke University, Durham, North Carolina 27708, USA
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