Renal Clearable Bi-Bi₂S₃ Heterostructure Nanoparticles for Targeting Cancer Theranostics

Recent development of precise nanomedicine has aroused an overwhelming interest in integration of diagnosis and treatment for cancers. Designing renal-clearable and targeting nanoparticles (NPs) has specific cancer theranostic implications and remains a challenging task. In this work, the ultrasmall folic acid (FA) and bovine serum albumin-modified Bi-Bi₂S₃ heterostructure nanoparticles NPs (Bi-Bi₂S₃/BSA&FA NPs) with excellent computed tomography (CT) and photoacoustic imaging abilities and outstanding photothermal performances were synthesized in an aqueous phase route via a simple method. Bi-Bi₂S₃/BSA&FA NPs have the following criteria: (i) Bi-Bi₂S₃/BSA&FA NPs with heterostructure possess better stability than Bi NPs and higher Bi content than Bi₂S₃ NPs, which are conducive to the enhancement of CT imaging effect; (ii) Bi-Bi₂S₃/BSA&FA NPs with FA molecules on the surface could target the tumor site effectively; (iii) Bi-Bi₂S₃/BSA&FA NPs could inhibit tumor growth effectively under 808 nm laser irradiation; (iv) ultrasmall Bi-Bi₂S₃/BSA&FA NPs could be cleared through kidney and liver within a reasonable time, avoiding a long-term retention/toxicity. Therefore, the renal clearable Bi-Bi₂S₃/BSA&FA NPs are a promising agent for targeting cancer theranostics.