Photodynamic therapy of lung cancer with photosensitizers based on polycationic derivatives of synthetic bacteriochlorin (experimental study)

Abstract

Background: One of the tasks of anticancer photodynamic therapy is increasing the efficacy of treatment of cancer nodes with large (clinically relevant) sizes using near-infrared photosensitizers (PS).

Methods: The anticancer efficacy and mechanisms of the photodynamic action of PS based on polycationic derivatives of synthetic bacteriochlorin against Lewis lung carcinoma were studied in vitro and in vivo.

Results: It was found that studied PS have high phototoxicity against Lewis lung carcinoma cells: the IC₅₀ values were about 0.8 μM for tetracationic PS and 0.5 μM for octacationic PS. In vivo studies have shown that these PS provide effective inhibition of the tumor growth with an increase in the lifespan of mice in the group by more than 130%, and more than 50% survival of mice in the group.

Conclusions: Photosensitizers based on polycationic derivatives of synthetic bacteriochlorin have high photodynamic efficacy caused by the induction of necrosis and apoptosis of cancer cells, including cancer stem cells, and a sharp decrease of mitotic and proliferative activity. Studied polycationic photosensitizers are much more effective at destroying cancer stem cells and newly formed cancer vessels in comparison with anionic photosensitizers, and ensure the cessation of tumor blood flow without hemorrhages and thrombosis.

Keywords: Cancer stem cells; Lewis lung carcinoma; Photodynamic therapy; Photosensitizer; Polycationic bacteriochlorin.