Magnetic-targeted capacitive heterostructure of polypyrrole for hypoxia-tolerant synergistic photodynamic/photothermal therapy under near infrared excitation.

Dual/Multi-modal photonanomedicines with the maximized antitumor efficacy has attracted extensive concerning. In this contribution, through photovoltaic engineering of photothermal conjugated polymer, a facile magnetic-targeted capacitive heterostructure of polypyrrole (upconversion nanoparticles (UCNPs)@SiO-FeO @polypyrrole (USFP)), capable of photodynamic therapy (PDT) and photothermal therapy (PTT) upon near infrared (NIR) excitation is purposefully developed. Owing to the optimized regulation of photoreaction pathway via photoinduced capacitance effect, the yield of reactive oxygen species (ROS) including O in polypyrrole can be significantly promoted. Notably, the external layers (porous silica and polypyrrole) of USFP allow the encounter and subsequent Fenton reaction between FeO and HO in tumor site, thereby further enhancing the photodynamic effect via an effective O supply. Upon intravenous injection into tumor-bearing mice, USFP can accumulate in tumors through a magnetic guidance, ablation experiments in vitro and in vivo confirmed the enhanced synergistic therapeutic effect and desirable biocompatibility of USFP.