Sulfhydryl-Modified Fe₃O₄@SiO₂ Core/Shell Nanocomposite: Synthesis and Toxicity Assessment in Vitro

The objectives of this study are to prepare sulfhydryl-modified Fe3O4@SiO2 core/shell magnetic nanocomposites, assess their toxicity in vitro, and explore their potential application in the biomedical fields. Fe3O4 nanoparticles synthesized by facile solvothermal method were coated with SiO2 via the Stöber method and further modified by the meso-2,3-dimercaptosuccinic acid (DMSA) to prepare Fe3O4@SiO2@DMSA nanoparticles. The morphology, structure, functional groups, surface charge, and magnetic susceptibility of the nanoparticles were characterized by transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectrometry, X-ray photoelectron spectroscopy, zeta potential analysis, dynamic laser scattering, and vibrating sample magnetometer. Cytotoxicity tests and hemolysis assay were also carried out. Experimental results show that the toxicity of sulfhydryl-modified Fe3O4@SiO2 core/shell nanoparticles in mouse fibroblast (L-929) cell lines is between grade 0 and grade 1, and the material lacks hemolytic activity, indicating good biocompatibility of this Fe3O4@SiO2@DMSA nanocomposite, which is suitable for further application in biochemical fields.