Photodynamic Therapy of Skin using Porphyrin Precursors: Optical Monitoring, Vascular Effects and Personalized Medicine

Abstract

Photodynamic therapy (PDT) is based on a photochemical reaction that involves three basic components: (1) a photosensitizer, which is a light-sensitive molecule that mediates transfer of light energy to molecular oxygen; (2) light of the appropriate wavelength that is absorbed by the photosensitizer, and (3) molecular oxygen. These components interact with each other and with the surrounding tissue, creating the photodynamic effect. The photodynamic processes are based on quantum mechanical principles that are described below and schematically illustrated in figure 1.