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Alvarez‐Lopez C, Cavazos‐Elizondo D, Heyne B, Kochevar IE, Aguirre‐Soto A. Nanocaging Rose Bengal to Inhibit Aggregation and Enhance Photo‐induced Oxygen Consumption. Photochem Photobiol 2022; 99:580-592. [PMID: 36529885 DOI: 10.1111/php.13746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 11/20/2022] [Indexed: 11/23/2022]
Abstract
Photosensitized crosslinking of proteins in tissues has many medical applications including sealing wounds, strengthening tissues, and beneficially altering tissue properties. Rose Bengal (RB) is used most frequently as the photosensitizer but is not as efficient as would be desired for broad utilization in medicine. Aggregation of RB, at the high concentrations used for medical treatments, decreases the yield of singlet oxygen, which mediates protein crosslinking. We hypothesized that nanocages that sequester RB would inhibit self-association, increasing photosensitization efficiency. We tested cucurbituril and cyclodextrin nanocages, demonstrating that hydroxypropyl-functionalized cyclodextrins are most effective in inhibiting RB aggregation. For these RB/cyclodextrin solutions, we investigated the effect of nanocaging on the photobleaching and oxygen consumption kinetics under 530 nm LED light in aqueous phosphate-buffered solutions. At 100 μm RB, the initial oxygen consumption rates increased by 58% and 80% compared with uncaged RB for the β and γ (2-hydroxypropyl) cyclodextrins, respectively. For 1 mm RB, the enhancement in these rates was much greater, about 200% and 300%, respectively. In addition, at 1 mm RB these two cyclodextrins increased the RB photobleaching rate by ~20% and ~75%. These results suggest that nanocages can minimize RB aggregation and may lead to higher-efficiency photo-medical therapies.
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Affiliation(s)
| | | | - Belinda Heyne
- Department of Chemistry. University of Calgary Calgary AB Canada
| | - Irene E. Kochevar
- Wellman Center for Photomedicine, Massachusetts General Hospital Harvard Medical School Boston MA United States
| | - Alan Aguirre‐Soto
- School of Engineering and Sciences Tecnologico de Monterrey Monterey Nuevo Leon Mexico
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Mendes B, Kassumeh S, Aguirre-Soto A, Pei Q, Heyne B, Kochevar IE. Influence of Rose Bengal Dimerization on Photosensitization. Photochem Photobiol 2021; 97:718-726. [PMID: 33426677 DOI: 10.1111/php.13379] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 01/07/2021] [Indexed: 12/30/2022]
Abstract
Protein crosslinking photosensitized by rose Bengal (RB2- ) has multiple medical applications and understanding the photosensitization mechanism can improve treatment effectiveness. To this end, we investigated the photochemical efficiencies of monomeric RB2- (RBM 2- ) and dimeric RB2- (RBD 2- ) and the optimal pH for anaerobic RB2- photosensitization in cornea. Absorption spectra and dynamic light scattering (DLS) measurements were used to estimate the fractions of RBM 2- and RBD 2- . RB2- self-photosensitized bleaching was used to evaluate the photoactivity of RBM 2- and RBD 2- . The pH dependence of anaerobic RB2- photosensitization was evaluated in ex vivo rabbit corneas. The 549 nm/515 nm absorption ratio indicated that concentrations > 0.10 mm RB contained RBD 2- . Results from DLS gave estimated mean diameters for RBM 2- and RBD 2- of 0.70 ± 0.02 nm and 1.75 ± 0.13 nm, respectively, and indicated that 1 mm RB2- contained equal fractions of RBM 2- and RBD 2- . Quantum yields for RB2- bleaching were not influenced by RBD 2- in RB2- solutions although accounting for RB2- concentration effects on the reaction kinetics demonstrated that RBD 2- is not a photosensitizer. Optimal anaerobic photosensitization occurred at pH 8.5 for solutions containing 200 mm Arg. These results suggest potential approaches to optimizing RBM 2- -photosensitized protein crosslinking in tissues.
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Affiliation(s)
- Bryan Mendes
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Stefan Kassumeh
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Alan Aguirre-Soto
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.,School of Engineering and Sciences, Tecnologico de Monterrey, Monterey, Nuevo León, México
| | - Qing Pei
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Belinda Heyne
- Department of Chemistry, University of Calgary, Calgary, AB, Canada
| | - Irene E Kochevar
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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Wertheimer CM, Mendes B, Pei Q, Brandt K, Kochevar IE. Arginine as an Enhancer in Rose Bengal Photosensitized Corneal Crosslinking. Transl Vis Sci Technol 2020; 9:24. [PMID: 32855871 PMCID: PMC7422776 DOI: 10.1167/tvst.9.8.24] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Accepted: 05/25/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose Oxygen-independent cornea crosslinking (CXL) using rose bengal (RB) and green light may have unique clinical applications. These studies were designed to gain insight into the arginine (arg)-enhanced anaerobic crosslinking process, to maximize crosslinking efficiency, and to test a clinically feasible method for oxygen-free CXL. Methods Rabbit corneas were treated ex vivo using 1 mM RB and 532 nm light. RB photodecomposition, monitored by absorption spectrophotometry, was used to optimize arg concentration and to develop an irradiation and re-dying protocol. The minimal effective green light fluence was identified by linear tensile strength measurements. RB penetration into the stroma was determined by fluorescence microscopy. To favor the anaerobic pathway, a contact lens was used to minimize stromal oxygen level during irradiation. Stromal cell toxicity was evaluated by a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay. Results RB photodecomposition reached 75% of its maximal effect at 200 mM arg and the optimal fluence increment was 32.7 J/cm2. The minimal effective fluence for cornea stiffening was 65.4 J/cm2. Placement of a contact lens promoted oxygen-independent cornea stiffening, similar to that obtained on isolated, oxygen-deprived cornea. RB penetration into the stroma with arg present was limited to ∼120 µm, about 25% deeper than without arg. Stromal cell toxicity was limited to the depth of RB and arg penetration. Conclusions An oxygen-independent pathway in cornea for RB-CXL was characterized and optimized, including a possible clinical protocol for its use. Translational Relevance Oxygen-independent RB-CXL is an efficient and effective process that can be developed further for unique clinical applications.
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Affiliation(s)
- Christian M Wertheimer
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA.,Ludwig-Maximilians-Universität Munich, Ophthalmology, Munich, Bayern, Germany
| | - Bryan Mendes
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Qing Pei
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Katharina Brandt
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA
| | - Irene E Kochevar
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
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Germann JA, Martínez-Enríquez E, Martínez-García MC, Kochevar IE, Marcos S. Corneal Collagen Ordering After In Vivo Rose Bengal and Riboflavin Cross-Linking. Invest Ophthalmol Vis Sci 2020; 61:28. [PMID: 32186674 PMCID: PMC7401826 DOI: 10.1167/iovs.61.3.28] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Purpose Photoactivated cornea collagen cross-linking (CXL) increases corneal stiffness by initiating formation of covalent bonds between stromal proteins. Because CXL depends on diffusion to distribute the photoinitiator, a gradient of CXL efficiency with depth is expected that may affect the degree of stromal collagen organization. We used second harmonic generation (SHG) microscopy to investigate the differences in stromal collagen organization in rabbit eyes after corneal CXL in vivo as a function of depth and time after surgery. Methods Rabbit corneas were treated in vivo with either riboflavin/UV radiation (UVX) or Rose Bengal/green light (RGX) and evaluated 1 and 2 months after CXL. Collagen fibers were imaged with a custom-built SHG scanning microscope through the central cornea (350 µm depth, 225 × 225 µm en face images). The order coefficient (OC), a metric for collagen organization, and total SHG signal were computed for each depth and compared between treatments. Results OC values of CXL-treated corneas were larger than untreated corneas by 27% and 20% after 1 month and 38% and 33% after 2 months for the RGX and UVX, respectively. RGX OC values were larger than UVX OC values by 3% and 5% at 1 and 2 months. The SHG signal was higher in CXL corneas than untreated corneas, both at 1 and 2 months after surgery, by 18% and 26% and 1% and 10% for RGX and UVX, respectively. Conclusions Increased OC corresponded with increased collagen fiber organization in CXL corneas. Changes in collagen organization parallel reported temporal changes in cornea stiffness after CXL and also, surprisingly, are detected deeper in the stroma than the regions stiffened by collagen cross-links.
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Redmond RW, Kochevar IE. Medical Applications of Rose Bengal‐ and Riboflavin‐Photosensitized Protein Crosslinking. Photochem Photobiol 2019; 95:1097-1115. [DOI: 10.1111/php.13126] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 03/27/2019] [Indexed: 01/20/2023]
Affiliation(s)
- Robert W. Redmond
- Wellman Center for Photomedicine Massachusetts General Hospital Harvard Medical School Boston MA
| | - Irene E. Kochevar
- Wellman Center for Photomedicine Massachusetts General Hospital Harvard Medical School Boston MA
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Kwok SJJ, Forward S, Wertheimer CM, Liapis AC, Lin HH, Kim M, Seiler TG, Birngruber R, Kochevar IE, Seiler T, Yun SH. Selective Equatorial Sclera Crosslinking in the Orbit Using a Metal-Coated Polymer Waveguide. Invest Ophthalmol Vis Sci 2019; 60:2563-2570. [PMID: 31212308 PMCID: PMC6586079 DOI: 10.1167/iovs.19-26709] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 05/15/2019] [Indexed: 12/03/2022] Open
Abstract
Purpose Photochemical crosslinking of the sclera is an emerging technique that may prevent excessive eye elongation in pathologic myopia by stiffening the scleral tissue. To overcome the challenge of uniform light delivery in an anatomically restricted space, we previously introduced the use of flexible polymer waveguides. We presently demonstrate advanced waveguides that are optimized to deliver light selectively to equatorial sclera in the intact orbit. Methods Our waveguides consist of a polydimethylsiloxane cladding and a polyurethane core, coupled to an optical fiber. A reflective silver coating deposited on the top and side surfaces of the waveguide prevents light leakage to nontarget, periorbital tissue. Postmortem rabbits were used to test the feasibility of in situ equatorial sclera crosslinking. Tensometry measurements were performed on ex vivo rabbit eyes to confirm a biomechanical stiffening effect. Results Metal-coated waveguides enabled efficient light delivery to the entire circumference of the equatorial sclera with minimal light leakage to the periorbital tissues. Blue light was delivered to the intact orbit with a coefficient of variation in intensity of 22%, resulting in a 45 ± 11% bleaching of riboflavin fluorescence. A 2-fold increase in the Young's modulus at 5% strain (increase of 92% P < 0.05, at 25 J/cm2) was achieved for ex vivo crosslinked eyes. Conclusions Flexible polymer waveguides with reflective, biocompatible surfaces are useful for sclera crosslinking to achieve targeted light delivery. We anticipate that our demonstrated procedure will be applicable to sclera crosslinking in live animal models and, potentially, humans in vivo.
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Affiliation(s)
- Sheldon J. J. Kwok
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, United States
- Harvard-MIT Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
| | - Sarah Forward
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, United States
| | - Christian M. Wertheimer
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, United States
| | - Andreas C. Liapis
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, United States
| | - Harvey H. Lin
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, United States
| | - Moonseok Kim
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, United States
| | - Theo G. Seiler
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, United States
- Institute for Refractive and Ophthalmic Surgery (IROC), Zurich, Switzerland
- Universitätsklinik für Augenheilkunde, Inselspital, Universität Bern, Bern, Switzerland
| | - Reginald Birngruber
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, United States
- Institut für Biomedizinische Optik, Universität zu Lübeck, Lübeck, Germany
| | - Irene E. Kochevar
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, United States
| | - Theo Seiler
- Institute for Refractive and Ophthalmic Surgery (IROC), Zurich, Switzerland
| | - Seok-Hyun Yun
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, United States
- Harvard-MIT Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
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Wertheimer CM, Elhardt C, Kaminsky SM, Pham L, Pei Q, Mendes B, Afshar S, Kochevar IE. Enhancing Rose Bengal-Photosensitized Protein Crosslinking in the Cornea. ACTA ACUST UNITED AC 2019; 60:1845-1852. [DOI: 10.1167/iovs.19-26604] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Christian M. Wertheimer
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Carolin Elhardt
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Steffen M. Kaminsky
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Linh Pham
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Qing Pei
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Bryan Mendes
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Sepideh Afshar
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Irene E. Kochevar
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
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Lorenzo-Martín E, Gallego-Muñoz P, Ibares-Frías L, Marcos S, Pérez-Merino P, Fernández I, Kochevar IE, Martínez-García MC. Rose Bengal and Green Light Versus Riboflavin–UVA Cross-Linking: Corneal Wound Repair Response. ACTA ACUST UNITED AC 2018; 59:4821-4830. [DOI: 10.1167/iovs.18-24881] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Elvira Lorenzo-Martín
- Departamento de Biología Celular, Histología y Farmacología, GIR de Técnicas Ópticas para el Diagnóstico, Universidad de Valladolid, Valladolid, Spain
| | - Patricia Gallego-Muñoz
- Departamento de Biología Celular, Histología y Farmacología, GIR de Técnicas Ópticas para el Diagnóstico, Universidad de Valladolid, Valladolid, Spain
| | - Lucía Ibares-Frías
- Departamento de Biología Celular, Histología y Farmacología, GIR de Técnicas Ópticas para el Diagnóstico, Universidad de Valladolid, Valladolid, Spain
- Departamento de Oftalmología, Hospital General Universitario Gregorio Marañón, Madrid, Spain
| | - Susana Marcos
- Instituto de Óptica, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Pablo Pérez-Merino
- Instituto de Óptica, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Itziar Fernández
- Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Instituto de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid, Valladolid, Spain
| | - Irene E. Kochevar
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - M. Carmen Martínez-García
- Departamento de Biología Celular, Histología y Farmacología, GIR de Técnicas Ópticas para el Diagnóstico, Universidad de Valladolid, Valladolid, Spain
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Seiler TG, Engler M, Beck E, Birngruber R, Kochevar IE. Interface Bonding With Corneal Crosslinking (CXL) After LASIK Ex Vivo. ACTA ACUST UNITED AC 2017; 58:6292-6298. [DOI: 10.1167/iovs.17-22426] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Theo G. Seiler
- Wellman Center for Photomedicine-Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
- Universitätsklinik für Augenheilkunde, Inselspital, Bern, Switzerland
- The Institut für Refraktive und Ophthalmo-Chirurgie (IROC), Zürich, Switzerland
| | - Marleen Engler
- Wellman Center for Photomedicine-Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Eric Beck
- Wellman Center for Photomedicine-Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Reginald Birngruber
- Wellman Center for Photomedicine-Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
- The Institut für Biomedizinische Optik, Universität zu Lübeck, Lübeck, Germany
| | - Irene E. Kochevar
- Wellman Center for Photomedicine-Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
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Alarcon EI, Poblete H, Roh H, Couture JF, Comer J, Kochevar IE. Rose Bengal Binding to Collagen and Tissue Photobonding. ACS Omega 2017; 2:6646-6657. [PMID: 31457260 PMCID: PMC6644953 DOI: 10.1021/acsomega.7b00675] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 09/11/2017] [Indexed: 05/19/2023]
Abstract
We investigated two critical aspects of rose Bengal (RB) photosensitized protein cross-linking that may underlie recently developed medical applications. Our studies focused on the binding of RB to collagen by physical interaction and the effect of this binding and certain amino acids on RB photochemistry. Molecular dynamics simulations and free-energy calculation techniques, complemented with isothermal titration calorimetry, provided insight into the binding between RB and a collagen-like peptide (CLP) at the atomic level. Electrostatic interactions dominated, which is consistent with the finding that RB bound equally well to triple helical and single chain collagen. The binding free energy ranged from -5.7 to -3 kcal/mol and was strongest near the positively charged amino groups at the N-terminus and on lysine side chains. At high RB concentration, a maximum of 16 ± 3 bound dye molecules per peptide was found, which is consistent with spectroscopic evidence for aggregated RB bound to collagen or the CLP. Within a tissue-mimetic collagen matrix, RB photobleached rapidly, probably due to electron transfer to certain protein amino acids, as was demonstrated in solutions of free RB and arginine. In the presence of arginine and low oxygen concentrations, a product absorbing at 510 nm formed, presumably due to dehalogenation after electron transfer to RB. In the collagen matrix without arginine, the dye generated singlet oxygen as well as the 510 nm product. These results provide the first evidence of the effects of a tissue-like environment on the photochemical mechanisms of rose Bengal.
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Affiliation(s)
- Emilio I. Alarcon
- Division
of Cardiac Surgery, University of Ottawa
Heart Institute, 40 Ruskin
Street, K1Y 4W7 Ottawa, ON, Canada
- Department
of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, 451 Smyth Road, K1H 8M5 Ottawa, ON, Canada
| | - Horacio Poblete
- Center
for Bioinformatics and Molecular Simulation, Universidad de Talca, 2 Norte 685, Casilla 721, Talca 3460000, Chile
- Institute
of Computational Comparative Medicine, Nanotechnology Innovation Center
of Kansas State, and Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas 66503, United States
| | - HeeGwang Roh
- Wellman
Center for Photomedicine, Massachusetts
General Hospital and Harvard Medical School, 40 Blossom Street, Boston, Massachusetts 02114, United States
| | - Jean-François Couture
- Department
of Biochemistry, Microbiology, and Immunology, Faculty of Medicine, University of Ottawa, 451 Smyth Road, K1H 8M5 Ottawa, ON, Canada
| | - Jeffrey Comer
- Institute
of Computational Comparative Medicine, Nanotechnology Innovation Center
of Kansas State, and Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas 66503, United States
| | - Irene E. Kochevar
- Wellman
Center for Photomedicine, Massachusetts
General Hospital and Harvard Medical School, 40 Blossom Street, Boston, Massachusetts 02114, United States
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Ortega-Martinez A, Touchette G, Zhu H, Kochevar IE, Franco W. Variations in the endogenous fluorescence of rabbit corneas after mechanical property alterations. J Biomed Opt 2017; 22:1-7. [PMID: 28933070 DOI: 10.1117/1.jbo.22.9.095005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 08/29/2017] [Indexed: 06/07/2023]
Abstract
Keratoconus is an eye disease in which the cornea progressively deforms due to loss of cornea mechanical rigidity, and thus causes deterioration of visual acuity. Techniques to characterize the mechanical characteristics of the cornea are important to better monitor changes and response to treatments. To investigate the feasibility of using the endogenous fluorescence of cornea for monitoring alterations of its mechanical rigidity, linear tensiometry was used to quantitate stiffness and Young's modulus (YM) after treatments that increase cornea stiffness (collagen photocross-linking) or decrease stiffness (enzymatic digestion). The endogenous ultraviolet fluorescence of cornea was also measured before and after these treatments. The fluorescence excitation/emission spectral ranges were 280 to 430/390 to 520 nm, respectively. A correlation analysis was carried out to identify fluorescence excitation/emission pairs whose intensity changes correlated with the stiffness. A positive correlation was found between variations in fluorescence intensity of the 415-/485-nm excitation/emission pair and YM of photocross-linked corneas. After treatment of corneas with pepsin, the YM decreased as the fluorescence intensity at 290-/390-nm wavelengths decreased. For weakening of corneas with collagenase, only qualitative changes in the fluorescence spectrum were observed. Changes in the concentration of native or newly created fluorescent molecular species contain information that may be directly or indirectly related to the mechanical structure of the cornea.
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Affiliation(s)
- Antonio Ortega-Martinez
- Massachusetts General Hospital, Wellman Center for Photomedicine, Boston, Massachusetts, United States
| | - Genna Touchette
- Eastern Michigan University, Department of Physics, Ypsilanti, Michigan, United States
| | - Hong Zhu
- Massachusetts General Hospital, Wellman Center for Photomedicine, Boston, Massachusetts, United States
- Harvard Medical School, Department of Dermatology, Boston, Massachusetts, United States
| | - Irene E Kochevar
- Massachusetts General Hospital, Wellman Center for Photomedicine, Boston, Massachusetts, United States
- Harvard Medical School, Department of Dermatology, Boston, Massachusetts, United States
| | - Walfre Franco
- Massachusetts General Hospital, Wellman Center for Photomedicine, Boston, Massachusetts, United States
- Harvard Medical School, Department of Dermatology, Boston, Massachusetts, United States
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12
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Kwok SJJ, Kim M, Lin HH, Seiler TG, Beck E, Shao P, Kochevar IE, Seiler T, Yun SH. Flexible Optical Waveguides for Uniform Periscleral Cross-Linking. Invest Ophthalmol Vis Sci 2017; 58:2596-2602. [PMID: 28494493 PMCID: PMC5433838 DOI: 10.1167/iovs.17-21559] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Purpose Scleral cross-linking (SXL) with a photosensitizer and light is a potential strategy to mechanically reinforce the sclera and prevent progressive axial elongation responsible for severe myopia. Current approaches for light delivery to the sclera are cumbersome, do not provide uniform illumination, and only treat a limited area of sclera. To overcome these challenges, we developed flexible optical waveguides optimized for efficient, homogeneous light delivery. Methods Waveguides were fabricated from polydimethylsiloxane elastomer. Blue light (445 nm) is coupled into the waveguide with an input fiber. Light delivery efficiency from the waveguide to scleral tissue was measured and fit to a theoretical model. SXL was performed on fresh porcine eyes stained with 0.5% riboflavin, using irradiances of 0, 25, and 50 mW/cm2 around the entire equator of the eye. Stiffness of scleral strips was characterized with tensiometry. Results Light delivery with a waveguide of tapered thickness (1.4–0.5 mm) enhanced the uniformity of light delivery, compared to a flat waveguide, achieving a coefficient of variation of less than 10%. At 8% strain, sclera cross-linked with the waveguides at 50 mW/cm2 for 30 minutes had a Young's modulus of 10.7 ± 1.0 MPa, compared to 5.9 ± 0.5 MPa for no irradiation, with no difference in stiffness between proximally and distally treated halves. The stiffness of waveguide-irradiated samples did not differ from direct irradiation at the same irradiance. Conclusions We developed flexible waveguides for periscleral cross-linking. We demonstrated efficient and uniform stiffening of a 5-mm-wide equatorial band of scleral tissue.
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Affiliation(s)
- Sheldon J J Kwok
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, United States 2Harvard-MIT Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
| | - Moonseok Kim
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, United States
| | - Harvey H Lin
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, United States
| | - Theo G Seiler
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, United States 3Institute for Refractive and Ophthalmic Surgery (IROC), Zurich, Switzerland
| | - Eric Beck
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, United States
| | - Peng Shao
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, United States
| | - Irene E Kochevar
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, United States
| | - Theo Seiler
- Institute for Refractive and Ophthalmic Surgery (IROC), Zurich, Switzerland
| | - Seok-Hyun Yun
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, United States 2Harvard-MIT Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States
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Gallego-Muñoz P, Ibares-Frías L, Lorenzo E, Marcos S, Peréz-Merino P, Bekesi N, Kochevar IE, Martínez-García MC. Corneal Wound Repair After Rose Bengal and Green Light Crosslinking: Clinical and Histologic Study. ACTA ACUST UNITED AC 2017; 58:3471-3480. [DOI: 10.1167/iovs.16-21365] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Patricia Gallego-Muñoz
- Departamento de Biología Celular, Histología y Farmacología, GIR de Técnicas Ópticas para el Diagnóstico, Universidad de Valladolid, Valladolid, Spain
| | - Lucía Ibares-Frías
- Departamento de Biología Celular, Histología y Farmacología, GIR de Técnicas Ópticas para el Diagnóstico, Universidad de Valladolid, Valladolid, Spain
| | - Elvira Lorenzo
- Departamento de Biología Celular, Histología y Farmacología, GIR de Técnicas Ópticas para el Diagnóstico, Universidad de Valladolid, Valladolid, Spain
| | - Susana Marcos
- Instituto de Óptica, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Pablo Peréz-Merino
- Instituto de Óptica, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Nandor Bekesi
- Instituto de Óptica, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Irene E. Kochevar
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - M. Carmen Martínez-García
- Departamento de Biología Celular, Histología y Farmacología, GIR de Técnicas Ópticas para el Diagnóstico, Universidad de Valladolid, Valladolid, Spain
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Bekesi N, Gallego-Muñoz P, Ibarés-Frías L, Perez-Merino P, Martinez-Garcia MC, Kochevar IE, Marcos S. Biomechanical Changes After In Vivo Collagen Cross-Linking With Rose Bengal-Green Light and Riboflavin-UVA. Invest Ophthalmol Vis Sci 2017; 58:1612-1620. [PMID: 28297026 DOI: 10.1167/iovs.17-21475] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To compare corneal biomechanical properties after in vivo and ex vivo cross-linking (CXL) using rose bengal-green light (RGX) or riboflavin-UVA (UVX). Methods Corneas of 30 rabbits were treated in vivo by the two CXL modalities monolaterally (Group 1) or bilaterally (Group 2). Rabbits in Group 1 were euthanized 1 month after treatments and in Group 2 two months after treatment. Ex vivo CXL was also performed. Eyes were measured by Scheimpflug air puff corneal deformation imaging (Corvis ST) under constant IOP. Corneal deformation parameters were assessed. Inherent corneal biomechanical properties were estimated using inverse finite element modeling. Results Peak to peak distance decreased 16% 2 months after RGX, and 4% and 20% 1 and 2 months after UVX, respectively. The equivalent Young's modulus (Eeq) increased relative to the control during the post treatment period for both RGX and UVX. The Eeq increased by factors of 3.4 (RGX) and 1.7 (UVX) 1 month and by factors of 10.7 (RGX) and 7.3 (UVX) 2 months after treatment. However, the Eeq values for ex vivo CXL were much greater than produced in vivo. The ex vivo Eeq was greater than the 1-month in vivo values by factors of 8.1 (RGX) and 9.1 (UVX) and compared with 2 month by factors of 2.5 (RGX) and 2.1 (UVX). Conclusions These results indicate that corneal stiffness increases after CXL, and further increases as a function of time after both RGX and UVX. Also, while biomechanical properties determined after ex vivo CXL are indicative of corneal stiffening, they may not provide entirely accurate information about the responses to CXL in vivo.
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Affiliation(s)
- Nandor Bekesi
- Instituto de Optica, Consejo Superior de Investigaciones Cientificas, Madrid, Spain
| | - Patricia Gallego-Muñoz
- Departamento de Biología Celular, Histología y Farmacología, GIR de Técnicas Ópticas para el Diagnóstico, Universidad de Valladolid, Valladolid, Spain
| | - Lucía Ibarés-Frías
- Departamento de Biología Celular, Histología y Farmacología, GIR de Técnicas Ópticas para el Diagnóstico, Universidad de Valladolid, Valladolid, Spain
| | - Pablo Perez-Merino
- Instituto de Optica, Consejo Superior de Investigaciones Cientificas, Madrid, Spain
| | - M Carmen Martinez-Garcia
- Departamento de Biología Celular, Histología y Farmacología, GIR de Técnicas Ópticas para el Diagnóstico, Universidad de Valladolid, Valladolid, Spain
| | - Irene E Kochevar
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Susana Marcos
- Instituto de Optica, Consejo Superior de Investigaciones Cientificas, Madrid, Spain
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Zhu H, Kochevar IE, Behlau I, Zhao J, Wang F, Wang Y, Sun X, Hamblin MR, Dai T. Antimicrobial Blue Light Therapy for Infectious Keratitis: Ex Vivo and In Vivo Studies. Invest Ophthalmol Vis Sci 2017; 58:586-593. [PMID: 28129422 PMCID: PMC5283079 DOI: 10.1167/iovs.16-20272] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Purpose To investigate the effectiveness of antimicrobial blue light (aBL) as an alternative or adjunctive therapeutic for infectious keratitis. Methods We developed an ex vivo rabbit model and an in vivo mouse model of infectious keratitis. A bioluminescent strain of Pseudomonas aeruginosa was used as the causative pathogen, allowing noninvasive monitoring of the extent of infection in real time via bioluminescence imaging. Quantitation of bacterial luminescence was correlated to colony-forming units (CFU). Using the ex vivo and in vivo models, the effectiveness of aBL (415 nm) for the treatment of keratitis was evaluated as a function of radiant exposure when aBL was delivered at 6 or 24 hours after bacterial inoculation. The aBL exposures calculated to reach the retina were compared to the American National Standards Institute standards to estimate aBL retinal safety. Results Pseudomonas aeruginosa keratitis fully developed in both the ex vivo and in vivo models at 24 hours post inoculation. Bacterial luminescence in the infected corneas correlated linearly to CFU (R2 = 0.921). Bacterial burden in the infected corneas was rapidly and significantly reduced (>2-log10) both ex vivo and in vivo after a single exposure of aBL. Recurrence of infection was observed in the aBL-treated mice at 24 hours after aBL exposure. The aBL toxicity to the retina is largely dependent on the aBL transmission of the cornea. Conclusions Antimicrobial blue light is a potential alternative or adjunctive therapeutic for infectious keratitis. Further studies of corneal and retinal safety using large animal models, in which the ocular anatomies are similar to that of humans, are warranted.
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Affiliation(s)
- Hong Zhu
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States 2Department of Ophthalmology, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Irene E Kochevar
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Irmgard Behlau
- Department of Medicine, Mount Auburn Hospital, Harvard Medical School, Cambridge, Massachusetts, United States 4School of Medicine, Tufts University, Boston, Massachusetts, United States
| | - Jie Zhao
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Fenghua Wang
- Department of Ophthalmology, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Yucheng Wang
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States 5Department of Laser Medicine, Chinese PLA General Hospital, Beijing, China
| | - Xiaodong Sun
- Department of Ophthalmology, Shanghai First People's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Michael R Hamblin
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Tianhong Dai
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
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Fairbairn NG, Ng-Glazier J, Meppelink AM, Randolph MA, Valerio IL, Fleming ME, Kochevar IE, Winograd JM, Redmond RW. Erratum: Light-Activated Sealing of Acellular Nerve Allografts following Nerve Gap Injury. J Reconstr Microsurg 2016; 32:e1. [PMID: 27341523 DOI: 10.1055/s-0036-1584882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Neil G Fairbairn
- Division of Plastic and Reconstructive Surgery, Massachusetts General Hospital, Boston, Massachusetts
| | - Joanna Ng-Glazier
- Division of Plastic and Reconstructive Surgery, Massachusetts General Hospital, Boston, Massachusetts
| | - Amanda M Meppelink
- Division of Plastic and Reconstructive Surgery, Massachusetts General Hospital, Boston, Massachusetts
| | - Mark A Randolph
- Division of Plastic and Reconstructive Surgery, Massachusetts General Hospital, Boston, Massachusetts
| | - Ian L Valerio
- Plastic Surgery Service, Walter Reed National Military Medical Center, Bethesda, Maryland
| | - Mark E Fleming
- Department of Orthopaedics, Walter Reed National Military Medical Center, Bethesda, Maryland
| | - Irene E Kochevar
- Wellman Centre for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Jonathan M Winograd
- Division of Plastic and Reconstructive Surgery, Massachusetts General Hospital, Boston, Massachusetts
| | - Robert W Redmond
- Wellman Centre for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts
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17
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Liu C, Vojnovic D, Kochevar IE, Jurkunas UV. UV-A Irradiation Activates Nrf2-Regulated Antioxidant Defense and Induces p53/Caspase3-Dependent Apoptosis in Corneal Endothelial Cells. Invest Ophthalmol Vis Sci 2016; 57:2319-27. [PMID: 27127932 PMCID: PMC4855825 DOI: 10.1167/iovs.16-19097] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Purpose To examine whether Nrf2-regulated antioxidant defense and p53 are activated in human corneal endothelial cells (CEnCs) by environmental levels of ultraviolet A (UV-A), a known stimulator of oxidative stress. Methods Immortalized human CEnCs (HCEnCi) were exposed to UV-A fluences of 2.5, 5, 10, or 25 J/cm2, then allowed to recover for 3 to 24 hours. Control HCEnCi did not receive UV-A. Reactive oxygen species (ROS) were measured using H2DCFDA. Cell cytotoxicity was evaluated by lactate dehydrogenase (LDH) release. Levels of Nrf2, HO-1, NQO-1, p53, and caspase3 were detected by immunnoblotting or real-time PCR. Activated caspase3 was measured by immunoblotting and a fluorescence assay. Results Exposure of HCEnCi to 5, 10, and 25 J/cm2 UV-A increased ROS levels compared with controls. Nrf2, HO-1, and NQO-1 mRNA increased 1.7- to 3.2-fold at 3 and 6 hours after irradiation with 2.5 and 5 J/cm2 UV-A. At 6 hours post irradiation, UV-A (5 J/cm2) enhanced nuclear Nrf2 translocation. At 24 hours post treatment, UV-A (5, 10, and 25 J/cm2) produced a 1.8- to 2.8-fold increase in phospho-p53 and a 2.6- to 6.0-fold increase in activated caspase3 compared with controls, resulting in 20% to 42% cell death. Conclusions Lower fluences of UV-A induce Nrf2-regulated antioxidant defense and higher fluences activate p53 and caspase3, indicating that even near-environmental levels of UV-A may affect normal CEnCs. This data suggest that UV-A may especially damage cells deficient in antioxidant defense, and thus may be involved in the etiology of Fuchs' endothelial corneal dystrophy (FECD).
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Affiliation(s)
- Cailing Liu
- Schepens Eye Research Institute Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
| | - Dijana Vojnovic
- Schepens Eye Research Institute Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
| | - Irene E Kochevar
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Ula V Jurkunas
- Schepens Eye Research Institute Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
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Bekesi N, Kochevar IE, Marcos S. Corneal Biomechanical Response Following Collagen Cross-Linking With Rose Bengal-Green Light and Riboflavin-UVA. Invest Ophthalmol Vis Sci 2016; 57:992-1001. [PMID: 26968733 DOI: 10.1167/iovs.15-18689] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To compare the biomechanical corneal response of two different corneal cross-linking (CXL) treatments, rose bengal-green light (RGX) and riboflavin-UVA (UVX), using noninvasive imaging. METHODS A total of 12 enucleated rabbit eyes were treated with RGX and 12 with UVX. Corneal dynamic deformation to an air puff was measured by high speed Scheimpflug imaging (Corvis ST) before and after treatment. The spatial and temporal deformation profiles were evaluated at constant intraocular pressure of 15 mm Hg, and several deformation parameters were estimated. The deformation profiles were modeled numerically using finite element analysis, and the hyperelastic corneal material parameters were obtained by inverse modeling technique. RESULTS The corneal deformation amplitude decreased significantly after both CXL methods. The material parameters obtained from inverse modeling were consistent with corneal stiffening after both RGX and UVX. Within the treated corneal volume, we found that the elasticity decreased by a factor of 11 after RGX and by a factor of 6.25 after UVX. CONCLUSIONS The deformation of UVX-treated corneas was smaller than the RGX-treated corneas. However, the reconstructed corneal mechanical parameters reveal that RGX produced in fact larger stiffening of the treated region (100-μm depth) than UVX (137-μm depth). Rose bengal-green light stiffens the cornea effectively, with shorter treatment times and shallower treated areas. Dynamic air puff deformation imaging coupled with mechanical simulations is a useful tool to characterize corneal biomechanical properties, assess different treatments, and possibly help optimize the treatment protocols.
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Affiliation(s)
- Nandor Bekesi
- Instituto de Optica Consejo Superior de Investigaciones Cientificas, Madrid, Spain
| | - Irene E Kochevar
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Susana Marcos
- Instituto de Optica Consejo Superior de Investigaciones Cientificas, Madrid, Spain
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19
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Senthil-Kumar P, Ni T, Randolph MA, Velmahos GC, Kochevar IE, Redmond RW. A light-activated amnion wrap strengthens colonic anastomosis and reduces peri-anastomotic adhesions. Lasers Surg Med 2016; 48:530-7. [PMID: 26996284 DOI: 10.1002/lsm.22507] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/02/2016] [Indexed: 12/14/2022]
Abstract
BACKGROUND AND OBJECTIVE Colonic anastomotic failure is a dreaded complication, and multiple surgical techniques have failed to eliminate it. Photochemical tissue bonding (PTB) is a method of sealing tissue surfaces by light-activated crosslinking. We evaluated if a human amniotic membrane (HAM), sealed over the anastomotic line by PTB, increases the anastomotic strength. STUDY DESIGN Sprague-Dawley rats underwent midline laparotomy followed by surgical transection of the left colon. Animals were randomized to colonic anastomosis by one of the following methods (20 per group): single-layer continuous circumferential suture repair (SR); SR with a HAM wrap attached by suture (SR+ HAM-S); SR with HAM bonded photochemically over the anastomotic site using 532 nm light (SR+ HAM-PTB); approximation of the bowel ends with only three sutures and sealing with HAM-PTB (3+ HAM-PTB). A control group underwent laparotomy alone with no colon resection (NR). Sub-groups (n = 10) were sacrificed at days 3 and 7 post-operatively and adhesions were evaluated. A 6 cm section of colon was then removed and strength of anastomosis evaluated by burst pressure (BP) measurement. RESULTS A fourfold increase in BP was observed in the SR+ HAM-PTB group compared to suture repair alone (94 ± 3 vs. 25 ± 8 mm Hg, P < 0.0001) at day 3. At day 7 the burst pressures were 165 ± 40 and 145 ± 31 mm Hg (P = 1), respectively. A significant decrease in peri-anastomotic adhesions was observed in the SR+ HAM-PTB group compared to the SR group at both time points (P < 0.001). CONCLUSION Sealing sutured colonic anastomotic lines with HAM-PTB increases the early strength of the repair and reduces peri-anastomotic adhesions. Lasers Surg. Med. 48:530-537, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Prabhu Senthil-Kumar
- Wellman Center for Photomedicine, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts, 02114.,Plastic Surgery Research Laboratory, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts, 02114
| | - Tao Ni
- Wellman Center for Photomedicine, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts, 02114.,Department of Burns and Plastic Surgery, No. 3 People's Hospital, and Institute of Traumatic Medicine, School of Medicine, Shanghai Jiao Tong University, Shanghai, 201900, P.R. China
| | - Mark A Randolph
- Plastic Surgery Research Laboratory, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts, 02114
| | - George C Velmahos
- Division of Trauma, Emergency Surgery and Surgical Critical Care, Department of Surgery, Massachusetts General Hospital, Boston, Massachusetts, 02114
| | - Irene E Kochevar
- Wellman Center for Photomedicine, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts, 02114
| | - Robert W Redmond
- Wellman Center for Photomedicine, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts, 02114
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Marcos S, Alejandre N, Lamela J, Dorronsoro C, Kochevar IE. Toward New Engagement Paradigms For Intraocular Lenses: Light-Initiated Bonding of Capsular Bag to Lens Materials. ACTA ACUST UNITED AC 2015; 56:4249-56. [DOI: 10.1167/iovs.15-17070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Susana Marcos
- Instituto de Óptica Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Nicolás Alejandre
- Instituto de Óptica Consejo Superior de Investigaciones Científicas, Madrid, Spain 2Fundación Jiménez Díaz, Madrid, Spain
| | - Jorge Lamela
- Instituto de Óptica Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Carlos Dorronsoro
- Instituto de Óptica Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Irene E. Kochevar
- Wellman Center for Photomedicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States
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Abstract
BACKGROUND AND OBJECTIVES We have developed a light-activated technology for rapidly sealing skin surgical wounds called photochemical tissue bonding (PTB). The goals of this study were to evaluate parameters influencing PTB in order to optimize its clinical efficacy and to determine whether PTB can be used to seal wounds in moderately to highly pigmented skin. STUDY DESIGN/MATERIALS AND METHODS Application of Rose Bengal (RB) followed by exposure to 532 nm was used to seal linear incisions (1.5 mm deep, 2 cm long) in lightly pigmented (Yorkshire) and darkly pigmented (Yucatan) swine skin. The force required to open the seal (the bonding strength) was measured by in situ tensiometry. Reflectance spectra, epidermal transmission spectra, and histology were used to characterize the skin. The relationships of RB concentration and fluence to bonding strength were established in Yorkshire skin. Surface temperature was measured during irradiations and cooling was used while sealing incisions in Yucatan skin. Monte Carlo simulations were carried out to estimate the effect of epidermal melanin on the power absorbed in the dermis at the incision interface. RESULTS The lowest fluence, 25 J/cm(2), delivered at an irradiance of 0.5 W/cm(2) substantially increased the bonding strength (∼ 10-fold) compared to controls in Yorkshire swine skin. Increasing the fluence to 100 J/cm(2) enhanced bonding strength by a further 1.5-fold. Application of 0.1% RB for 2 minutes produced the greatest bonding strength using 100 J/cm(2) and limited the penetration of RB to an ∼ 50 μm band on the dermal incision wall. Reflectance spectra indicated that Yorkshire skin had minimal melanin and that Yucatan skin was a good model for highly pigmented human skin. In Yucatan skin, the bonding strength increased 1.7-fold using 0.1% RB and 200 J/cm(2) at 1.5 W/cm(2) with cooling and epinephrine. Monte Carlo simulation indicated that absorption of 532 nm light by epidermal melanin in dark skin decreased the power absorbed along the incision in the dermis by a factor of 2.7. CONCLUSIONS These results suggest that in lightly pigmented skin the PTB treatment time can be shortened without compromising the bonding strength. Sealing incisions using PTB in moderately and highly pigmented skin will require a careful balance of irradiance and cooling.
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Affiliation(s)
- Nan Xu
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; Dermatology Department, Shanghai East Hospital, Tongji University, Shanghai, China
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Liu C, Chen Y, Kochevar IE, Jurkunas UV. Decreased DJ-1 leads to impaired Nrf2-regulated antioxidant defense and increased UV-A-induced apoptosis in corneal endothelial cells. Invest Ophthalmol Vis Sci 2014; 55:5551-60. [PMID: 25082883 DOI: 10.1167/iovs.14-14580] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
PURPOSE To investigate the role of DJ-1 in Nrf2-regulated antioxidant defense in corneal endothelial cells (CECs) at baseline and in response to ultraviolet A (UV-A)-induced oxidative stress. METHODS DJ-1-deficient CECs were obtained by transfection of an immortalized normal human corneal endothelial cell line (HCECi) with DJ-1 small interfering RNA (siRNA) or by isolation of CECs from ex vivo corneas of DJ-1 knockout mice. Levels of reactive oxygen species (ROS), protein carbonyls, Nrf2 subcellular localization, Nrf2 target genes, and protein interaction between Keap1/Nrf2 and Cul3/Nrf2 were compared between normal and DJ-1-deficient CECs. Oxidative stress was induced by irradiating HCECi cells with UV-A, and cell death and levels of activated caspase3 and phospho-p53 were determined. RESULTS DJ-1 siRNA-treated cells exhibited increased levels of ROS production and protein carbonyls as well as a 2.2-fold decrease in nuclear Nrf2 protein when compared to controls. DJ-1 downregulation led to attenuated gene expression of Nrf2 and its target genes HO-1 and NQO1. Similar levels of Nrf2 inhibitor, Keap1, and Cul3/Nrf2 and Keap1/Nrf2 were observed in DJ-1 siRNA-treated cells as compared to controls. Ultraviolet A irradiation resulted in a 3.0-fold increase in cell death and elevated levels of activated caspase3 and phospho-p53 in DJ-1 siRNA-treated cells compared to controls. CONCLUSIONS Downregulation of DJ-1 impairs nuclear translocation of Nrf2, causing decreased antioxidant gene expression and increased oxidative damage. The decline in DJ-1 levels leads to heightened CEC susceptibility to UV-A light by activating p53-dependent apoptosis. Targeting the DJ-1-Nrf2 axis may provide a potential therapeutic approach for enhancing antioxidant defense in corneal endothelial disorders.
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Affiliation(s)
- Cailing Liu
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
| | - Yuming Chen
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
| | - Irene E Kochevar
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, United States
| | - Ula V Jurkunas
- Schepens Eye Research Institute, Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States
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Yao M, Gu C, Doyle FJ, Zhu H, Redmond RW, Kochevar IE. Why is Rose Bengal More Phototoxic to FibroblastsIn VitroThanIn Vivo? Photochem Photobiol 2013; 90:297-305. [DOI: 10.1111/php.12215] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 11/18/2013] [Indexed: 11/29/2022]
Affiliation(s)
- Min Yao
- Wellman Center for Photomedicine; Massachusetts General Hospital; Harvard Medical School; Boston MA
| | - Chuan Gu
- Wellman Center for Photomedicine; Massachusetts General Hospital; Harvard Medical School; Boston MA
| | - Francis J. Doyle
- Wellman Center for Photomedicine; Massachusetts General Hospital; Harvard Medical School; Boston MA
| | - Hong Zhu
- Wellman Center for Photomedicine; Massachusetts General Hospital; Harvard Medical School; Boston MA
| | - Robert W. Redmond
- Wellman Center for Photomedicine; Massachusetts General Hospital; Harvard Medical School; Boston MA
| | - Irene E. Kochevar
- Wellman Center for Photomedicine; Massachusetts General Hospital; Harvard Medical School; Boston MA
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Cherfan D, Verter EE, Melki S, Gisel TE, Doyle FJ, Scarcelli G, Yun SH, Redmond RW, Kochevar IE. Collagen cross-linking using rose bengal and green light to increase corneal stiffness. Invest Ophthalmol Vis Sci 2013; 54:3426-33. [PMID: 23599326 DOI: 10.1167/iovs.12-11509] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
PURPOSE Photochemical cross-linking of corneal collagen is an evolving treatment for keratoconus and other ectatic disorders. We evaluated collagen cross-linking by rose bengal plus green light (RGX) in rabbit eyes and investigated factors important for clinical application. METHODS Rose bengal (RB, 0.1%) was applied to deepithelialized corneas of enucleated rabbit eyes for 2 minutes. The diffusion distance of RB into the stroma was measured by fluorescence microscopy on frozen sections. RB-stained corneas were exposed to green (532-nm) light for 3.3 to 9.9 minutes (50-150 J/cm(2)). Changes in the absorption spectrum during the irradiation were recorded. Corneal stiffness was measured by uniaxial tensiometry. The spatial distribution of the stromal elastic modulus was assessed by Brillouin microscopy. Viable keratocytes were counted on H&E-stained sections 24 hours posttreatment. RESULTS RB penetrated approximately 100 μm into the corneal stroma and absorbed >90% of the incident green light. RGX (150 J/cm(2)) increased stromal stiffness by 3.8-fold. The elastic modulus increased in the anterior approximately 120 μm of stroma. RB was partially photobleached during the 2-minute irradiation, but reapplication of RB blocked light transmission by >70%. Spectral measurements suggested that RGX initiated cross-linking by an oxygen-dependent mechanism. RGX did not decrease keratocyte viability. CONCLUSIONS RGX significantly increases cornea stiffness in a rapid treatment (≅12 minutes total time), does not cause toxicity to keratocytes and may be used to stiffen corneas thinner than 400 μm. Thus, RGX may provide an attractive approach to inhibit progression of keratoconus and other ectatic disorders.
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Affiliation(s)
- Daniel Cherfan
- Boston University Medical Sciences Program, Boston, MA, USA
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Ni T, Senthil-Kumar P, Dubbin K, Aznar-Cervantes SD, Datta N, Randolph MA, Cenis JL, Rutledge GC, Kochevar IE, Redmond RW. A photoactivated nanofiber graft material for augmented Achilles tendon repair. Lasers Surg Med 2012; 44:645-52. [PMID: 22911554 DOI: 10.1002/lsm.22066] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/23/2012] [Indexed: 12/17/2022]
Abstract
BACKGROUND AND OBJECTIVE Suture repair of Achilles tendon rupture can cause infection, inflammation and scarring, while prolonged immobilization promotes adhesions to surrounding tissues and joint stiffness. Early mobilization can reduce complications provided the repair is strong enough to resist re-rupture. We have developed a biocompatible, photoactivated tendon wrap from electrospun silk (ES) to provide additional strength to the repair that could permit early mobilization, and act as a barrier to adhesion formation. STUDY DESIGN/MATERIAL AND METHODS ES nanofiber mats were prepared by electrospinning. New Zealand white rabbits underwent surgical transection of the Achilles tendon and repair by: (a) SR: standard Kessler suture + epitendinous suture (5-0 vicryl). (b) ES/PTB: a single stay suture and a section of ES mat, stained with 0.1% Rose Bengal (RB), wrapped around the tendon and bonded with 532 nm light (0.3 W/cm(2) , 125 J/cm(2) ). (c) SR + ES/PTB: a combination of (a) and (b). Gross appearance, extent of adhesion formation and biomechanical properties of the repaired tendon were evaluated at Days 7, 14, or 28 post-operatively (n = 8 per group at each time point). RESULTS Ultimate stress (US) and Young's modulus (E) in the SR group were not significantly different from the ES/PTB group at Days 7 (US, P = 0.85; E, P = 1), 14 (US, P = 0.054; E, P = 1), and 28 (US, P = 0.198; E, P = 0.12) post-operatively. Adhesions were considerably greater in the SR group compared to the ES/PTB group at Days 7 (P = 0.002), 14 (P < 0.0001), and 28 (P < 0.0001). The combination approach of SR + ES/PTB gave the best outcomes in terms of E at 7 (P < 0.016) and 14 days (P < 0.016) and reduced adhesions compared to SR at 7 (P < 0.0001) and 14 days (P < 0.0001), the latter suggesting a barrier function for the photobonded ES wrap. CONCLUSION Photochemical sealing of a ES mat around the tendon repair site provides considerable benefit in Achilles tendon repair. Lasers Surg. Med. 44: 645-652, 2012. © 2012 Wiley Periodicals, Inc.
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Affiliation(s)
- Tao Ni
- Department of Burns and Plastic Surgery, No. 3 People's Hospital, and Institute of Traumatic Medicine; School of Medicine, Shanghai Jiao Tong University, Shanghai 201900, P.R. China
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Yang P, Yao M, DeMartelaere SL, Redmond RW, Kochevar IE. Light-activated sutureless closure of wounds in thin skin. Lasers Surg Med 2011; 44:163-7. [DOI: 10.1002/lsm.21137] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2011] [Indexed: 11/08/2022]
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Verter EE, Gisel TE, Yang P, Johnson AJ, Redmond RW, Kochevar IE. Light-Initiated Bonding of Amniotic Membrane to Cornea. ACTA ACUST UNITED AC 2011; 52:9470-7. [DOI: 10.1167/iovs.11-7248] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- E. Eri Verter
- From the Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Thomas E. Gisel
- From the Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Penggao Yang
- From the Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts; the 2Department of Burns and Plastic Surgery, No. 3 People's Hospital, Shanghai, China; and
| | - Anthony J. Johnson
- the Department of Ophthalmology, Brooke Army Medical Center, San Antonio, Texas
| | - Robert W. Redmond
- From the Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
| | - Irene E. Kochevar
- From the Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
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Bélanger E, Henry FP, Vallée R, Randolph MA, Kochevar IE, Winograd JM, Lin CP, Côté D. In vivo evaluation of demyelination and remyelination in a nerve crush injury model. Biomed Opt Express 2011; 2:2698-708. [PMID: 22091449 PMCID: PMC3184878 DOI: 10.1364/boe.2.002698] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 07/29/2011] [Accepted: 08/01/2011] [Indexed: 05/18/2023]
Abstract
Nerves of the peripheral nervous system have, to some extent, the ability to regenerate after injury, particularly in instances of crush or contusion injuries. After a controlled crush injury of the rat sciatic nerve, demyelination and remyelination are followed with functional assessments and imaged both ex vivo and in vivo over the course of 4 weeks with video-rate coherent anti-Stokes Raman scattering (CARS) microscopy. A new procedure compatible with live animal imaging is developed for performing histomorphometry of myelinated axons. This allows quantification of demyelination proximal and remyelination distal to the crush site ex vivo and in vivo respectively.
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Gu C, Ni T, Verter EE, Redmond RW, Kochevar IE, Yao M. Photochemical tissue bonding: A potential strategy for treating limbal stem cell deficiency. Lasers Surg Med 2011; 43:433-42. [DOI: 10.1002/lsm.21066] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Franco RA, Dowdall JR, Bujold K, Amann C, Faquin W, Redmond RW, Kochevar IE. Photochemical repair of vocal fold microflap defects. Laryngoscope 2011; 121:1244-51. [DOI: 10.1002/lary.21797] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Accepted: 02/23/2011] [Indexed: 01/27/2023]
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Kossodo S, Wong WR, Simon G, Kochevar IE. Effects of UVR and UVR-induced Cytokines on Production of Extracellular Matrix Proteins and Proteases by Dermal Fibroblasts Cultured in Collagen Gels¶. Photochem Photobiol 2011. [DOI: 10.1111/j.1751-1097.2004.tb09861.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Yao M, Yaroslavsky A, Henry FP, Redmond RW, Kochevar IE. Phototoxicity is not associated with photochemical tissue bonding of skin. Lasers Surg Med 2010; 42:123-31. [DOI: 10.1002/lsm.20869] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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35
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Choi WS, Mitsumoto A, Kochevar IE. Involvement of reactive oxygen species in TGF-beta1-induced tropoelastin expression by human dermal fibroblasts. Photochem Photobiol 2010; 85:1425-33. [PMID: 19709383 DOI: 10.1111/j.1751-1097.2009.00611.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Chronic exposure to solar UV radiation causes marked changes in the dermal extracellular matrix that underlie the loss of resiliency and increased laxity observed in photoaged skin. In particular, the dermal elastin content increases substantially and the normal, well-organized elastic fibers are replaced by amorphous elastotic material. Transforming growth factor-beta1 (TGF-beta1) stimulates synthesis of elastin by dermal fibroblasts and may mediate the increase in elastin in chronically photodamaged skin. We investigated pathways involved in the TGF-beta1-induced increase in tropoelastin (TE), the soluble elastin monomer and assessed the role of reactive oxygen species (ROS) in the regulation of TE mRNA. Antioxidants and an inhibitor of NADPH oxidase blocked TGF-beta1-induced TE mRNA increase even when added 1.5 h after TGF-beta1, although ROS were detected for only 30 min. The TE mRNA increase required activation of Smad4, shown using Smad4 siRNA, and also involved the ERK1/2, p38 and JNK MAP kinases but not PI3K. ROS did not enhance signaling through Smad2 but did enhance activation of p38 and ERK1/2 at 10 min after TGF-beta1. These results indicate that Smad and MAPK pathways mediate TGF-beta1-induced TE expression and that ROS are required for both early signal transduction and later steps that increase elastin.
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Affiliation(s)
- Won Seon Choi
- Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA
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Yamaura M, Yao M, Yaroslavsky I, Cohen R, Smotrich M, Kochevar IE. Low level light effects on inflammatory cytokine production by rheumatoid arthritis synoviocytes. Lasers Surg Med 2009. [PMID: 19347944 DOI: 10.1002/lsm.v41:4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/24/2023]
Abstract
BACKGROUND AND OBJECTIVE Low level light therapy (LLLT) is being evaluated for treating chronic and acute pain associated with rheumatoid arthritis (RA) and other inflammatory diseases. The mechanisms underlying the effectiveness of LLLT for pain relief in RA are not clear. The objectives of this study were to determine whether LLLT decreased production of pro-inflammatory cytokines by cells from RA joints, and, if so, to identify cellular mechanisms. STUDY DESIGN/MATERIALS AND METHODS Synoviocytes from RA patients were treated with 810 nm radiation before or after addition of tumor necrosis factor-alpha (TNF-alpha). mRNA for TNF-alpha, interleukin (IL)-1beta, IL-6, and IL-8 was measured after 30, 60, and 180 minutes using RT-PCR. Intracellular and extracellular protein levels for 12 cytokines/chemokines were measured at 4, 8, and 24 hours using multiplexed ELISA. NF-kappaB activation was detected using Western blotting to follow degradation of IkappaBalpha and nuclear localization of the p65 subunit of NF-kappaB. RESULTS Radiation at 810 nm (5 J/cm(2)) given before or after TNF-alpha decreases the mRNA level of TNF-alpha and IL-1beta in RA synoviocytes. This treatment using 25 J/cm(2) also decreases the intracellular levels of TNF-alpha, IL-1beta, and IL-8 protein but did not affect the levels of seven other cytokines/chemokines. TNF-alpha-induced activation of NF-kappaB is not altered by 810 nm radiation using 25 J/cm(2). CONCLUSIONS The mechanism for relieving joint pain in RA by LLLT may involve reducing the level of pro-inflammatory cytokines/chemokines produced by synoviocytes. This mechanism may be more general and underlie the beneficial effects of LLLT on other inflammatory conditions.
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Affiliation(s)
- Maki Yamaura
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
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Ibusuki S, Papadopoulos A, Ranka MP, Halbesma GJ, Randolph MA, Redmond RW, Kochevar IE, Gill TJ. Engineering cartilage in a photochemically crosslinked collagen gel. J Knee Surg 2009; 22:72-81. [PMID: 19216355 DOI: 10.1055/s-0030-1247729] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This study's purpose was to investigate whether photochemically crosslinking collagen gel to encapsulate chondrocytes (articular, auricular, costal) would permit new cartilage formation in vivo, and to determine whether this neocartilage had the ability to integrate with existing native cartilage. Chondrocytes from swine were embedded in collagen gel that was photochemically crosslinked using riboflavin and visible light. Controls were collagen gels containing cells that were not crosslinked. Cylindrical implants (0.1 cc) were placed in athymic mice for 4 and 8 weeks. To study integration, the constructs were crosslinked within articular cartilage rings and implanted in the mice. Samples were analyzed in terms of macroscopic, microscopic, and biochemical aspects. Photocrosslinking did not affect the amount of glycosaminoglycan and type II collagen produced by the cells. We found that photochemical crosslinking collagen gel enhances the physical parameters of the gel and permits new cartilage formation that can integrate with existing native cartilage.
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Affiliation(s)
- Shinichi Ibusuki
- Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
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Bargagna-Mohan* P, Mohan* R, Russo L, Kochevar IE, Fini ME. Cell Lines and Transgenic Mice Expressing a Matrix Metalloproteinase-9 Promoter-Driven Reporter Gene: Potential for Assay of Ultraviolet Light Effects and Light-Inhibiting Compounds. Cutan Ocul Toxicol 2008; 26:383-97. [DOI: 10.1080/15569520701662924] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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39
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Echague AV, Farinelli WA, Li VW, Redmond RW, Kochevar IE. 124
Photochemical Tissue Bonding of Apligraf to Skin. Wound Repair Regen 2008. [DOI: 10.1111/j.1067-1927.2005.130216ab.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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40
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O'Neill AC, Randolph MA, Bujold KE, Kochevar IE, Redmond RW, Winograd JM. Photochemical sealing improves outcome following peripheral neurorrhaphy. J Surg Res 2008; 151:33-9. [PMID: 18599081 DOI: 10.1016/j.jss.2008.01.025] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2007] [Revised: 01/10/2008] [Accepted: 01/18/2008] [Indexed: 01/14/2023]
Abstract
INTRODUCTION Peripheral nerve transection initiates a complex molecular response in the severed nerve endings, resulting in the release of neurotrophic and neurotropic factors that are central to axonal survival and regeneration. In this study we tested the hypothesis that sealing the neurorrhaphy site from the surrounding environment using a photochemically bonded nerve wrap would optimize the endoneural environment and enhance regeneration and nerve function recovery. MATERIALS AND METHODS Adult rats underwent unilateral sciatic nerve transection and standard epineural nerve repair. The repair site was wrapped with amniotic membrane or autologous vein and then was either sealed using photochemical tissue bonding (PTB) or secured with sutures. Photochemical sealing without a wrap was also carried out. Functional recovery was assessed at 2-wk intervals using walking track analysis and nerve histomorphometry was assessed at 12 wk. RESULTS Treating nerves with PTB-sealed amnion significantly improved functional recovery and increased distal axon and fiber diameters and myelin thickness compared to nerves treated with standard neurorrhaphy alone. Direct PTB sealing of the repair site also improved function. Neither amnion secured with sutures nor vein wraps exhibited improved functional or histological recovery compared to standard neurorrhaphy. CONCLUSIONS These results suggest that sealing the peripheral nerve repair site with amnion using a photochemical technique may lead to earlier restoration of neural homeostasis and consequent enhanced repair of nerve injury.
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Affiliation(s)
- Anne C O'Neill
- Plastic Surgery Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
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41
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O'Neill AC, Winograd JM, Zeballos JL, Johnson TS, Randolph MA, Bujold KE, Kochevar IE, Redmond RW. Microvascular anastomosis using a photochemical tissue bonding technique. Lasers Surg Med 2008; 39:716-22. [PMID: 17960755 DOI: 10.1002/lsm.20548] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND AND OBJECTIVES Photochemical tissue bonding (PTB) combines photoactive dyes with visible light to create fluid-tight seals between tissue surfaces without causing collateral thermal damage. The potential of PTB to improve outcomes over standard of care microsurgical reanastomoses of blood vessels in ex vivo and in vivo models was evaluated. STUDY DESIGN The mechanical strength and integrity of PTB and standard microsurgical suture repairs in ex vivo porcine brachial arteries (n = 10) were compared using hydrostatic testing of leak point pressure (LPP). Femoral artery repair in vivo was measured in Sprague-Dawley rats using either standard microvascular sutures (n = 20) or PTB (n = 20). Patency was evaluated at 6 hours (n = 10) and 8 weeks post-repair (n = 10) for each group. RESULTS PTB produced significantly higher LPPs (1,100+/- 150 mmHg) than suture repair (350+/-40 mmHg, P<0.001) in an ex vivo study. In an in vivo study all femoral arteries in both suture and PTB repair groups were patent at 6 hours post-repair. At 8 weeks post-repair the patency rate was 80% for both groups. No evidence of aneurysm formation was seen in either group and bleeding was absent from the repair site in the PTB-treated vessels, in contrast to the suture repair group. CONCLUSION PTB is a feasible microvascular repair technique that results in an immediate, mechanically robust bond with short- and long-term patency rates equal to those for standard suture repair.
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Affiliation(s)
- Anne C O'Neill
- Plastic Surgery Research Laboratory, Harvard Medical School, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
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42
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43
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Johnson TS, O'Neill AC, Motarjem PM, Amann C, Nguyen T, Randolph MA, Winograd JM, Kochevar IE, Redmond RW. Photochemical Tissue Bonding: A Promising Technique for Peripheral Nerve Repair. J Surg Res 2007; 143:224-9. [PMID: 17543988 DOI: 10.1016/j.jss.2007.01.028] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2006] [Indexed: 11/29/2022]
Abstract
BACKGROUND Photochemical tissue bonding (PTB) is a novel tissue repair technique that uses visible light and a photosensitizing dye to crosslink proteins on tissue surfaces. This technique has been successfully demonstrated in a number of tissue repair models. An ideal nerve repair technique would be atraumatic and avoid placement of foreign bodies at the repair site. The epineurium is suited to photochemical repair as it is thin, translucent and has a relatively high collagen content. This study was designed to determine if PTB could be successfully applied in a peripheral nerve repair model. MATERIAL AND METHODS Forty Sprague Dawley rats underwent transection of the sciatic nerve. Animals were then randomized to four treatment groups; epineurial suture repair, epineurial cuff with PTB, epineurial cuff alone, and no repair. Functional recovery was assessed at 10 day intervals using walking track analysis and sciatic function index calculations. At 90 days postoperatively animals were sacrificed and sciatic nerves harvested for histology and histomorphometry. RESULTS Functional recovery in the suture repair and epineural cuff with PTB groups were not significantly different (-70.6 +/- 17.8 versus -76.9 +/- 10.3, P = 0.64) at 90 days postrepair. Histology showed good axonal regeneration with all repair techniques. Histomorphometric analysis found no significant difference between the repair groups. CONCLUSIONS This study illustrates that peripheral nerves can be successfully repaired using a photochemical tissue bonding technique with results similar to those achieved with the current gold standard. With further development and refinement PTB may prove a useful tool in peripheral nerve repair.
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Affiliation(s)
- T Shane Johnson
- Plastic Surgery Research Laboratory, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
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44
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Ibusuki S, Halbesma GJ, Randolph MA, Redmond RW, Kochevar IE, Gill TJ. Photochemically Cross-Linked Collagen Gels as Three-Dimensional Scaffolds for Tissue Engineering. ACTA ACUST UNITED AC 2007; 13:1995-2001. [PMID: 17518705 DOI: 10.1089/ten.2006.0153] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Collagen gels have many favorable attributes for tissue engineering, but the gels undergo dramatic contraction when cells are added because of the weak noncovalent bonds that form during spontaneous gelation. We hypothesized that photochemically cross-linking collagen gels would make suitable scaffolds for tissue engineering with favorable cell viability and minimal gel contraction. Rose Bengal and riboflavin were chosen as candidate photo-initiators for gel cross-linking using 532- and 458-nm-light wavelengths, respectively. Chondrocyte viability was measured after initial gelation for several concentrations of initiators. Cell viability and gel contraction were then measured using chondrocytes and fibroblasts over 7 days of culture. Rose Bengal used at concentrations necessary for gelation resulted in little or no cell viability. Short-term viability results showed that 0.25- or 0.5-mM concentrations of riboflavin, and 40 s of illumination permitted more than 90% cell viability. Using riboflavin concentrations of 0.25 or 0.5 mM, long-term chondrocyte viability was 113.1 +/- 11.6% and 25.4 +/- 2.7%, respectively, at day 7. Although non-cross-linked chondrocyte constructs contracted to 59.9 +/- 11.8% of their original diameter and fibroblasts contracted to 24.9 +/- 5.0% of their original diameter by day 7, the cross-linked constructs retained 88.8 +/- 7.4% and 85.5 +/- 5.0% of the original diameter, respectively. In conclusion, by photochemically cross-linking collagen gels using riboflavin and visible light, stable gel scaffolds with favorable cell survival can be produced.
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Affiliation(s)
- Shinichi Ibusuki
- Department of Orthopedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
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Abstract
UVA radiation is a major environmental stress on skin, causing acute and chronic photodamage. These responses are mediated by reactive oxygen species (ROS), although the cellular source of these ROS is unknown. We tested the hypotheses that UVA-induced activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is required for ROS generation in human keratinocytes (HK) and that these ROS initiate rapid prostaglandin E2 (PGE2) synthesis. Treatment of HK with a non-toxic dose of UVA rapidly increased NADPH oxidase activity and intracellular ROS, which were partially blocked by an inhibitor of NADPH oxidase and by a mitochondria-selective antioxidant. Depleting the Nox1 isoform of the catalytic subunit of NADPH oxidase using small interfering RNA (siRNA) blocked the UVA-induced ROS increase, indicating that ROS produced by mitochondria or other sources are downstream from Nox1. Nox1 siRNA also blocked UVA-initiated PGE2 synthesis. The mechanism for activation of Nox1 is mediated by an increase in intracellular calcium. Ceramide, which has been proposed to mediate responses to UVA in HK, also activated NADPH oxidase. These results indicate that UVA activates Nox1-based NADPH oxidase to produce ROS that stimulate PGE2 synthesis, and that Nox1 may be an appropriate target for agents designed to block UVA-induced skin injury.
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Affiliation(s)
- Antonio Valencia
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
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48
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Zhuang S, Kochevar IE. Ultraviolet A Radiation Induces Rapid Apoptosis of Human Leukemia Cells by Fas Ligand-Independent Activation of the Fas Death Pathway¶. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2003)0780061uarira2.0.co2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Valencia A, Rajadurai A, Carle AB, Kochevar IE. 7-Dehydrocholesterol enhances ultraviolet A-induced oxidative stress in keratinocytes: roles of NADPH oxidase, mitochondria, and lipid rafts. Free Radic Biol Med 2006; 41:1704-18. [PMID: 17145559 PMCID: PMC1880892 DOI: 10.1016/j.freeradbiomed.2006.09.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2006] [Revised: 08/23/2006] [Accepted: 09/05/2006] [Indexed: 12/20/2022]
Abstract
Long wavelength solar UVA radiation stimulates formation of reactive oxygen species (ROS) and prostaglandin E(2) (PGE(2)), which are involved in skin photosensitivity and tumor promotion. High levels of 7-dehydrocholesterol (7-DHC), the precursor to cholesterol, cause exaggerated photosensitivity to UVA in patients with Smith-Lemli-Opitz syndrome (SLOS). Partially replacing cholesterol with 7-DHC in keratinocytes rapidly (<5 min) increased UVA-induced ROS, intracellular calcium, phospholipase A(2) activity, PGE(2), and NADPH oxidase activity. UVA-induced ROS and PGE(2) production were inhibited in these cells by depleting the Nox1 subunit of NADPH oxidase using siRNA or using a mitochondrial radical quencher, MitoQ. Partial replacement of cholesterol with 7-DHC also disrupted membrane lipid raft domains, although depletion of cholesterol, which also disrupts lipid rafts, did not affect UVA-induced increases in ROS and PGE(2). Phospholipid liposomes containing 7-DHC were more rapidly oxidized by a free radical mechanism than those containing cholesterol. These results indicate that 7-DHC enhances rapid UVA-induced ROS and PGE(2) formation by enhancing free radical-mediated membrane lipid oxidation and suggests that this mechanism might underlie the UVA photosensitivity in SLOS.
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Affiliation(s)
- Antonio Valencia
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Thier-224, 55 Fruit Street, Boston, MA 02114, USA
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50
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Thompson BD, Jin Y, Birnbaumer L, Kochevar IE, Wu MX. Antagonism between Gαi2 and Gαi3 in CXCR3‐mediated signaling. FASEB J 2006. [DOI: 10.1096/fasebj.20.5.lb77] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Brian D Thompson
- DermatologyMassachusetts General HospitalEdwards 205, 55 Fruit StreetBostonMA02114
| | - Yongzhu Jin
- DermatologyMassachusetts General HospitalEdwards 205, 55 Fruit StreetBostonMA02114
| | - Lutz Birnbaumer
- National Institute of Environmental Health SciencesSouth Campus 101/A214, PO Box 12233Research Triangle ParkNC27709
| | - Irene E Kochevar
- DermatologyMassachusetts General HospitalEdwards 205, 55 Fruit StreetBostonMA02114
| | - Mei X Wu
- DermatologyMassachusetts General HospitalEdwards 205, 55 Fruit StreetBostonMA02114
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