A biomimetic one-pot synthesis of versatile Bi2S3/FeS2 theranostic nanohybrids for tumor-targeted photothermal therapy guided by CT/MR dual-modal imaging

Constructing versatile theranostic nanoplatforms that combine diagnostic and therapeutic moieties has shown great promise in the area of precision nanomedicine. However, the limitations on biosecurity, efficiency, and accessibility still need to be addressed. Herein, Bi2S3/FeS2 nanohybrids (NHs) were fabricated by a facile and biomimetic one-pot strategy using bovine serum albumin (BSA) as both the sulfur provider to achieve the nucleation and reaction nanocages to regulate the growth of NHs. Upon modification with folic acid (FA), the final obtained Bi2S3/FeS2@BSA-FA NHs could successfully target folate receptor α overexpressed 4T1 tumor cells. Moreover, CCK-8 assay and histopathologic evaluation confirmed the favorable biocompatibility of Bi2S3/FeS2@BSA-FA NHs, which is the premise of subsequent research. In addition, both in vitro and in vivo tests demonstrated that the Bi2S3/FeS2@BSA-FA NHs can serve as computed tomography (CT)/magnetic resonance (MR) dual mode imaging contrast agents, which possess a high X-ray absorption coefficient of 8.02 HU mM−1 and transverse relaxivity (53.9 mM−1s−1). And these two clinical imaging modes could complement each other. After intravenous injection, Bi2S3/FeS2@BSA-FA NHs exhibited efficient tumor homing, as shown by imaging and biodistribution measurement. Notably, when irradiated with 808 nm NIR laser (1.5 W.cm−2), the tumor growth of Bi2S3/FeS2@BSA-FA-treated group could be suppressed effectively, proving the high efficacy of photothermal therapy with these NHs. Thus, our research represents a facile and “green” approach for the construction of multifunctional theranostic reagents.