Functionalization of 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY)-based photosensitizers with Triphenylphosphonium (TPP) for mitochondria-targeted fluorescence bioimaging and photodynamic therapy

Abstract

Functionalization of BODIPY dyes with TPP substituents endowed them with mitochondria-targeting capabilities. The uniodinated BODIPY control displayed good biocompatibility, low cytotoxicity in the dark, and exceptional cellular imaging capabilities; however, it did not exhibit photodynamic therapeutic properties upon excitation at 530 nm. Dual functional photosensitizers were obtained in the case of mono- and di-iodinated BODIPY derivatives, which exhibited mitochondria-targeting capabilities and provided clear fluorescence confocal bioimages, while efficiently generating high levels of singlet oxygen species and displaying photodynamic therapeutic activity toward two cancer cell lines following LED irradiation. Overall, the results presented herein demonstrate the considerable potential for the use of TPP-functionalized BODIPY dyes as viable agents for fluorescence-imaging-guided photodynamic therapy (PDT) for cancer treatment.