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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] [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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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] [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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