Synthesis and photophysical properties of amphiphilic halogenated bacteriochlorins: new opportunities for photodynamic therapy of cancer

Photodynamic therapy (PDT) is a promising treatment for several types of cancers. It involves the synergetic effect of light, oxygen and an appropriate photosensitizer. Extensive studies on the synthetic modulation of the structure of tetrapyrrolic macrocycles allowed for the optimization of chemical and physical properties of such photosensitizers. The progress from porphyrins to chlorins and more recently to bacteriochlorins clearly shows the improvements achieved in PDT photosensitizers. This paper summarizes our recent contribution to the synthesis of stable amphiphilic halogenated meso-tetraarylbacteriochlorins. Their photophysics, in vitro cytotoxicity and phototoxicity are presented and their potential use as photosensitizer for PDT application is assessed.