Liposome(Ce6+ICG) For Combined Controlled Photodynamic And Photothermal Therapies

Photodynamic therapy (PDT) is a promising cancer treatment modality. In PDT, photosensitizers located in tumor produce singlet oxygen(1O2) upon exposure to appropriate wavelengths, which will effectively kill cancer cells, destroy the tumor vascular system and lead to an immune response to damage the structure and function of tumor. However, in the practices of many photosensitizers used in PDT have several deficiencies such as short tissue penetration depth, limited tumor specificity and phototoxicity under sunlight, especially when photosensitizers inevitably distribute in skin and produce 1O2 under sunshine, which may result in serious skin photosensitivity.To solve these problems, upconvertion nanoparticle, ligand linked nanometerials and various quenchers have been reported to optimizing PDT.Herein, we introduced a liposome(Ce6+ICG) in which both ICG and Ce6 were encapsulated. The fluorescence and 1O2 generation experiments under a series of laser strategies showed a strong Ce6 fluorescence quenching and inhibition of 1O2 generation in the presence of ICG. We also found the generation of 1O2 would recover till ICG was degraded upon Near infrared light(NIR) irradiation. In vitro anti-tumor efficacy study was conducted using MCF-7 cell lines. The results showed a significantly better anti-tumor efficacy with combined PDT with photothermal therapy(PTT) after the NIR irradiation.In conclusion, our liposome(Ce6+ICG) provides a new method for combined NIR activatable PDT with PTT in cancer cells.