In situ synthesis of multifunctional tellurium nanorods stabilized by polypeptide-engineered for photothermal-sonodynamic combination therapy of tumors

Nanoparticles containing elemental tellurium (Te) have been aroused extensive attention in biomedical applications. However, the ideal synthesis methods and effective anti-cancer strategies of Te nanoparticles remain great challenges. In this study, genetically engineered polypeptide (PC(10)ARGD)-capped Te nanorods (P-TeNRs) was in situ synthesized. The excellent dispersion of P-TeNRs with average lengths of 25.2 +/- 4.65 nm and diameters of 6.5 +/- 0.83 nm were confirmed by TEM. PC(10)ARGD was integrated onto the surface of Te nanorods to enhance the stability and biocompatibility of P-TeNRs. P-TeNRs exhibited the excellent photothermal conversion performance under irradiation of NIR laser and the reactive oxygen species (ROS) generating capacity under ultrasound (US) irradiation, which can achieve photothermal therapy and sonodynamic therapy of tumors. Compared with single photothermal therapy and sonodynamic therapy, the results of in vitro and in vivo experiments showed that the combination therapy has a synergistic effect on breast 4T1 tumors. In addition, the results of in vivo toxicity assay suggested that synthesized P-TeNRs presented negligible toxicity. These results demonstrate that this P-TeNRs can be engineered as a novel theranostic nanoplatform for synergistic photothermal-sonodynamic therapy of tumors.