Molecular phthalocyanine-based photosensitizers for photodynamic therapy

Phthalocyanines represent a versatile class of functional dyes. Owing to their desirable spectroscopic and photophysical properties, high photostability, and ease of chemical and physical modification, these compounds have emerged as promising photosensitizers for photodynamic therapy. This chapter aims to summarize the recent development of molecular phthalocyanine-based photosensitizers being reported over the last five years, including hydrophilic analogues with non-ionic, cationic, or anionic moieties, and bioconjugated derivatives substituted with carbohydrates, peptides, nucleic acids, polyamines, or folic acid. Novel phthalocyanines that exhibit dual functions and can be activated by tumor-associated stimuli are also described. The review will focus on their molecular design, synthesis, photophysical characteristics, and in vitro and in vivo photodynamic activities.