Cytotoxicity of Uncoated and Polyvinyl Alcohol Coated Superparamagnetic Iron Oxide Nanoparticles

Superparamagnetic iron oxide nanoparticles (SPION) are being increasingly used in various biomedical applications such as hyperthermia, cell and protein separation, enhancing resolution of magnetic resonance imaging, and drug delivery. However, the toxicity data for SPION are limited. In this study, uncoated and single polyvinyl alcohol coated SPION with high chemical reactivity (due to the bigger surface area) were synthesized using a coprecipitation method. Cytotoxicity of these magnetic nanoparticles and their ability to cause arrest in cell life-cycles was investigated. Interaction of these nanoparticles with adhesive mouse fibroblast cell line (L929) was probed using MTT assay. High concentrations of coated SPION (i.e., 100, 200, and 400 mM) demonstrated high cell viability following an exposure to the cells. Treated cells, via coated magnetic nanoparticles, did not showed evident necrosis, apoptosis (via propidium iodide staining), or cell cycle arrest in moderate concentration, i.e., 200 mM. However, the coated nanoparticles at the highest concentration (400 mM) caused both apoptosis and cell cycle arrest in G(1) phase, possibly due to the irreversible DNA damage and repair of oxidative DNA lesions. Uncoated nanoparticles showed significant apoptosis amount at the highest concentration. The mentioned damaged occurred because of proteins attachments to the surface of nanoparticles, leading to the formation of protein corona on the shell of magnetic particles. The associations of proteins on the surface of nanoparticles were confirmed by UV/Vis spectroscopy. Finally, the effect of particle surface (i.e., uncoated and coated) on the cell cycle was studied.