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.
Photochem Photobiol. 2021 Jul;97(4):718-726. doi: 10.1111/php.13379. Epub 2021 Feb 5.
Protein crosslinking photosensitized by rose Bengal (RB ) has multiple medical applications and understanding the photosensitization mechanism can improve treatment effectiveness. To this end, we investigated the photochemical efficiencies of monomeric RB (RB ) and dimeric RB (RB ) and the optimal pH for anaerobic RB photosensitization in cornea. Absorption spectra and dynamic light scattering (DLS) measurements were used to estimate the fractions of RB and RB . RB self-photosensitized bleaching was used to evaluate the photoactivity of RB and RB . The pH dependence of anaerobic RB photosensitization was evaluated in ex vivo rabbit corneas. The 549 nm/515 nm absorption ratio indicated that concentrations > 0.10 mm RB contained RB . Results from DLS gave estimated mean diameters for RB and RB of 0.70 ± 0.02 nm and 1.75 ± 0.13 nm, respectively, and indicated that 1 mm RB contained equal fractions of RB and RB . Quantum yields for RB bleaching were not influenced by RB in RB solutions although accounting for RB concentration effects on the reaction kinetics demonstrated that RB 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 RB -photosensitized protein crosslinking in tissues.
Rose Bengal (RB ) 介导的蛋白质交联具有多种医学应用，了解其光敏化机制可以提高治疗效果。为此，我们研究了单体 RB (RB ) 和二聚体 RB (RB ) 的光化学效率，以及角膜中厌氧 RB 光敏化的最佳 pH 值。采用吸收光谱和动态光散射 (DLS) 测量来估计 RB 和 RB 的分数。RB 自敏化漂白用于评估 RB 和 RB 的光活性。在离体兔角膜中评估了厌氧 RB 光敏化的 pH 值依赖性。549nm/515nm 吸收比表明浓度>0.10mm RB 含有 RB 。DLS 的结果给出了 RB 和 RB 的平均直径，分别为 0.70±0.02nm 和 1.75±0.13nm，表明 1mm RB 含有等量的 RB 和 RB 。尽管考虑到 RB 浓度对反应动力学的影响表明 RB 不是光敏剂，但 RB 溶液中 RB 的存在并不影响 RB 漂白的量子产率。含 200mm Arg 的溶液中最佳厌氧光敏化发生在 pH 8.5。这些结果为优化组织中 RB 介导的蛋白质交联提供了潜在的方法。
