Electrostatic self-assembled Iridium(III) nano-photosensitizer for selectively disintegrated and mitochondria targeted photodynamic therapy

Abstract Photodynamic therapy (PDT) is one of effective cancer therapy methods. It is important to develop a PDT reagent with tumor-targeted ability, high phototoxicity and low dark toxicity. In this study, an iridium(III) complex (Irpy) can electrostatically self-assemble with hyaluronic acid (HA) to form nanostructured Irpy-HA, which exhibited stable spheroid structure and outstanding ability of singlet oxygen (1O2) generation. The photophysical property of Irpy has been well studied, which qualified green light absorption ability and could emit red phosphorescence. The nanostructure and stability of self-assembled Irpy-HA have been well investigated, which can keep its nanostructure at least 30 days. More important, Irpy-HA can target to a CD44 receptor in cancer cell membrane for enhancing internalization and selective disintegration. Then, Irpy can accumulate in mitochondria and generate 1O2 to realize PDT-induced cell apoptosis by green light irradiation. The Irpy-HA could be used as a nanophotosensitizer for effective photodynamic therapy.