A versatile Bi2S3/MnO2 based nano-theranostic agent for triple-modal imaging guided photothermal/photodynamic synergistic therapy

Versatile nano-theranostic agents are highly desirable for the precision nanomedicine of tumors in recent years. In this work, a multifunctional diagnostic and therapeutic agent Bi2S3-MnO2@BSA-Ce6 (BMBC) was successfully prepared by a combination strategy of facile chemical coupling and biomineralization under mild conditions. These BMBC nanoparticles with an average diameter of 17.6 ± 4.6 nm exhibited favorable physiological stability and negligible toxicity. This agent expressed outstanding performance of photothermal conversion (η = 45.8%) under 808 nm laser radiation and generation of 1O2 under 650 nm laser irradiation. Due to the strong X-ray attenuation performance of element Bi and the highly effective magnetic moment of Mn2+, this agent exhibited favorable performance of X-ray computed tomography (CT) imaging (35.60 HU•mL•mg−1) and magnetic resonance (MR) imaging (r1 = 5.22 mM−1•s−1) in vitro. Furthermore, most of the HeLa cells treated with BMBC NPs were dead in the MTT and Calcein-AM/PI staining experiments, demonstrating the excellent effect of intracellular synergistic therapy. Overall, this theranostic agent could serve as a promising nano-platform for photothermal/photodynamic synergistic therapy of tumors under the guidance of infrared thermal (IRT)/MR/CT imaging.