Exploring BODIPY Derivatives as Singlet Oxygen Photosensitizers for PDT

Abstract

This Minireview is devoted to honoring the memory of Dr. Thomas Dougherty, a pioneer of modern photodynamic therapy (PDT). It compiles the most important inputs made by our research group since 2012 in the development of new photosensitizers based on BODIPY chromophore. The photophysical properties of BODIPYs can be finely tuned to serve as efficient photosensitizers for the generation of singlet oxygen also, thanks to the rich BODIPY chemistry. These two factors, photonic tuning and workable chemistry, have turned BODIPY as one of the most promising chromophore for the development of improved photosensitizers for photodynamic therapy (PDT). In this line, this minireview is mainly related to the establishment of chemical methods and structural designs for enabling singlet oxygen generation in BODIPYs. The approaches include the incorporation of heavy atoms such as halogenated atoms, iodine and bromide, in different number and positions of the in BODIPY scaffold, and also transition metal atoms by their complexation with Ir (III) center; and as low-toxic tactics (without involving heavy metals) several orthogonal BODIPY dimers with different substitution patterns. The advantages and drawbacks of the different molecular design based on BODIPY dyes are described.