Towards Characteristics of Photodynamic Drugs Specifically Aimed at Microvascular Diseases

Photodynamic therapy (PDT) is a versatile methodology to treat various diseases but the drugs (photosensitizers) specifically aimed at individual character of diseases are urgently needed. Among those, the perilenoquinoid photosensitizers were thought of low PDT effectiveness to solid tumors due to low absorption on the “photodynamic window” but may be specially suitable for PDT to some microvascular diseases, such as age-related macular degeneration (AMD) and port wine stains (PWS), as well as other superficial diseases. Two strategies were discussed to convert the photosensitizers into clinically acceptable drugs in consideration of the drug-delivery and biological activity.