Synthesis of superparamagnetic Fe3O4-PEG400 nanoparticles: Investigation of interaction with proteins and toxicity on cells

Investigation of nanoparticle (NP)-protein interactions is crucial, as it provides critical insights into the behavior of NPs within biological systems. In this study, magnetite nanoparticles (Fe3O4 NPs) were coated with polyethylene glycol 400 (PEG400) using a novel modified chemical co-precipitation method. The structural, morphological, and magnetic properties of Fe3O4-PEG400 NPs were characterized. The NPs show superparamagnetism, very small size, and high colloidal stability. After that, the effect of Fe3O4-PEG400 NPs was investigated on proteins (human serum albumin: HSA and lysozyme: Lyso) and cells (fibroblast) using fluorescence spectroscopy, circular dichroism (CD) spectropolarimetry, and MTT assay. Results showed minimal alteration in the secondary structure of proteins but the tertiary structure of proteins shows some flexibility. Moreover, the cytotoxicity test indicates Fe3O4-PEG400 NPs show better biocompatibility than Fe3O4 NPs and has an IC50 of 65 mu g/mL. In summary, the biocompatibility, stability, and superparamagnetism of Fe3O4-PEG400 NPs enhance their potential for biomedical applications.