Thiophene-Based Organic D–π–A Dyes as Potent Sensitizers for Photodynamic Therapy

Abstract

In this study, synthetically readily accessible, thiophene-based organic D–π–A sensitizers exerted high phototoxicity and are valuable as sensitizer templates for use in photodynamic therapy (PDT). Evaluation of the antitumor activity of our previously synthesized D–π–A sensitizers under photoirradiation revealed their potent phototoxicity. The structural requirements of the D–π–A sensitizer for phototoxicity were elucidated with the rapid synthesis of structurally simplified analogues and evaluation of their antitumor activity under photoirradiation. Our developed sensitizers mainly accumulated in mitochondria and damaged cancer cells through both Type I and Type II mechanisms. The developed new template could be useful in the future development of sensitizers that could fulfil the requirements for PDT.