Development of Iridium(III)-Based Sensitizers for Photodynamic Therapy

According to the World Health Organization (WHO), cancer is the second world leading cause of deaths with approximatively 9.6 million fatal cases in 2018. For centuries, the scientific world has been seeking for solutions to cure the disease. Huge advances have been made but the conventional treatments such as chemotherapy, radiotherapy, and surgery, still needs to be optimised due to the unwanted side effects of therapy. Researchers focus now on the development of treatments where the goals are to achieve high selectivity and efficacy. Photodynamic therapy consists of an innovative and minimal invasive treatment which requires three elements: molecular oxygen, light, and a photosensitizer. The selectivity of this therapy is ascribed to the focalisation of the light source which activates only the illuminated photosensitizer. Photodynamic therapy has applications in various medical fields such as oncology, ophthalmology, skin diseases etc. As this therapy remains in its infancy, only a few drugs have been approved to date. In this project, we report on the synthesis of different bis-cyclometalated iridium(III) complexes as photosensitizer for photodynamic therapy. The characterization to obtain their electrochemical and photophysical properties was carried out. Finally, preliminary studies in presence of biological relevant models revealed that some complexes have a potential for cleaving biological material upon light excitation.