Intelligent protein-coated bismuth sulfide and manganese oxide nanocomposites obtained by biomineralization for multimodal imaging-guided enhanced tumor therapy

Abstract

Radiotherapy (RT) has been used clinically to overcome cancer in recent decades. However, the abnormal tumor microenvironment (TME), involving hypoxia, acidosis and a dense extracellular matrix, is found to be related to the resistance of tumors to RT. Herein, intelligent bovine serum albumin (BSA)-coated Bi₂S₃ and MnO₂ (Bi₂S₃–MnO₂) nanocomposites synthesized via biomineralization are capable of modulating the hypoxic TME effectively to enhance the efficacy of RT. After intravenous injection, the BSA-Bi₂S₃–MnO₂ nanocomposites show efficient accumulation in tumors, where endogenous H₂O₂ can react with MnO₂ to generate oxygen in situ, leading to increased tumor oxygenation to overcome the hypoxia-associated resistance to RT. Moreover, the photothermal effect induced by the BSA-Bi₂S₃–MnO₂ nanocomposites further relieves hypoxia in the TME and, finally, synergistically improves the effects of RT. In this work, we present a simple strategy to fabricate intelligent therapeutic nanoparticles to improve therapeutic efficiency towards cervical cancer.