Biomineralization of Bi2S3-Gd2O3 nanocomposites: a novel approach for enhanced photothermal and MRI applications

In this study, Bi2S3-Gd2O3 nanocomposites (Bi2S3-Gd2O3@BSA) were prepared via biomineralization using albumin as a template, and the nanomaterials were directed to the tumor site through surface folic acid modification. Among these materials, Bi2S3 serves as an effective photothermal conversion agent (PTA) for photothermal therapy at tumor sites, attributed to its impressive photothermal conversion efficiency. In contrast, Gd2O3, being a paramagnetic substance, can serve effectively as a contrast agent in the magnetic resonance imaging (MRI). According to in vitro and in vivo experiments, the nanomaterials exhibit low toxicity, favorable biocompatibility, and outstanding photothermal properties. Upon the exposure to 808 nm laser irradiation, the nanomaterials quickly reach the therapeutic temperature necessary for effective tumor treatment. With folic acid modification, these nanomaterials accumulate in the tumor region, enabling efficient treatment. This strategy provides a fresh outlook for the purposeful design of diagnostic agents aimed at tumor imaging and therapy.