In vitro and in vivo evaluation of a pyropheophorbide-a derivative as a potential photosensitizer for age-related macular degeneration

Abstract

Abstract Photodynamic therapy (PDT) has been demonstrated to be an effective and safe treatment for subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD). The photosensitizer is crucial factor in the efficacy of PDT. In this study, the physicochemical properties and the biological activity of a pyropheophorbide-a derivative, 2-(1-methoxyethyl)-2-devinylpyropheophorbide-a (MEP) had been evaluated in vivo and in vitro . MEP had a characteristic long wavelength absorption peak at 664 nm and the singlet oxygen quantum yield was determined as 0.38. In vitro , MEP showed low dark cytotoxicity and high photocytotoxicity, reducing the cell viability in a drug dose – dependent and light dose – dependent manner. In vivo , MEP could selectively localize to experimental CNV in BN rats, resulting in occlusion of CNV with minimal damage to retina tissues. The results indicate that MEP has the perspective to be developed as a safe and effective photosensitizer in PDT for AMD.