Triphenylphosphonium-functionalized nanocomposites as carriers of a platinum diimine complex for photodynamic therapy.

The photodamage induced by PDT usually occurs at the site where the photosensitizers accumulate in the tumor cells, thus the modulation of intrinsic apoptosis by mitochondria-targeting PDT drugs might be a promising way to enhance the therapeutic efficacy of PDT drugs against tumor cells. Novel triphenylphosphonium-functionalized nanocomposites employed as carriers of a photoactive platinum diimine complex have been fabricated and characterized. Upon irradiation, the IC value of photosensitizer-loaded triphenylphosphonium-functionalized nanocomposites was found to be 17.4 or 14.4 times lower than that of the photosensitizer studied alone against HCT116 cells or A549 cells, respectively. The results suggested that the triphenylphosphonium- functionalized nanocomposites as drug delivery vehicles could significantly enhance the photodynamic efficacy of the photosensitizer.