Fabrication of Multitargeting and pH-Regulated Nanocomposites for Antitumor Photodynamic Therapy Based on Triphenylphosphine and Graphene Oxide.

Targeted delivery of photosensitizer for antitumor photodynamic therapy has received much attention recently. In this research, a multitargeting graphene oxide (GO) nanosystem (GFFP-TPPa) was fabricated based on the magnetically targeted nano-FeO, active targeted folic acid (FA), and mitochondria-targeted triphenylphosphine, aiming to provide an effective drug delivery system of photosensitizer for improved photodynamic therapy against human tumor. The effective photosensitizer release from GFFP-TPPa under mild acidic pH condition (such as tumor microenvironment) suggested our designed nanosystem could reduce cutaneous phototoxicity of nanoparticles (NPs) in normal cells environment, which was further verified by the observation that the fluorescence of GFFP-TPPa was significantly quenched compared with free PPa. Research of cellular morphological variation, uptaking test, and intracellular single oxygen detection has validated the effectiveness of GFFP-TPPa NPs against tumor cells and potential fluorescence imaging function. Moreover, GFFP-TPPa NPs have excellent superparamagnetic properties and FA-targeted property of NPs, which was verified by the tumor cellular uptake of GFFP-TPPa. Finally, the precise deliver of photosensitizer to mitochondria has been proved by Mito-Tracker Green organelle localization. Our research indicated that the fabricated nanosystem could be applied conveniently for PDT based on multitargetability.