Photosensitizer doped colloidal mesoporous silica nanoparticles for three-photon photodynamic therapy

Multiphoton microscopy and nanoparticle-assisted photodynamic therapy are two important areas in biophotonics research. In this paper, we combined these two technologies together. Photosensitizer (HPPH) doped colloidal mesoporous silica nanoparticles were synthesized and systematically characterized. Based on a confocal microscope equipped with a 1560 nm femtosecond laser, we showed: (1) direct three-photon luminescence from HPPH doped nanoparticles, which were uptaken by tumor cells, and (2) cytotoxicity towards tumor cells by HPPH under three-photon excitation. Nanoparticle-assisted three-photon photodynamic therapy can be a promising technology for disease diagnosis and in vivo/clinical therapy.