Pyroelectric-Inspired SnSe/rGO Nanoparticles for Heat Shock Protein Inhibition in ROS-Assisted Photothermal Tumor Therapy

Although photothermal therapy is widely employed for tumor treatment because of its high tumor cell selectivity and low apoptosis resistance, heat-shock proteins (HSPs) impart resistance to heat-induced apoptosis in tumor cells, thus diminishing the therapeutic effectiveness. To this end, tin selenide (SnSe) was grown in situ on reduced graphene oxide (rGO) nanosheets to construct a photothermal-thermoelectric SnSe/rGO nanosystem. The rGO component converted near-infrared light energy into localized thermal energy, resulting in the thermal ablation of tumor cells. Meanwhile, SnSe converted temperature fluctuations into pyroelectric charges, which interacted with surrounding O-2 molecules to generate reactive oxygen species that oxidized the amino acids on the HSPs, which changed the protein conformation and functionally damaged the tumor cells. In addition, rGO functioned as an efficient electron acceptor to increase electron mobility, thus enhancing the thermoelectric conversion efficiency of SnSe. Then, the SnSe/rGO nanosystem was incorporated into a poly-l-lactic acid bone scaffold to prevent tumor recurrence. Results showed that the composite scaffold not only exhibited good photothermal and thermoelectric effects. In vitro cell tests demonstrated that the scaffold generated O-1(2) based on temperature fluctuations and the antitumor rate reached 86.6% against osteosarcoma MG-63 cells.