Interaction of Bare and Gold-Coated Superparamagnetic Iron Oxide Nanoparticles with Fetal Bovine Serum

Superparamagnetic iron oxide nanoparticles (SPIONs) are being increasingly used in various biomedical processes such as hyperthermia, cell and protein separation, enhancing resolution of magnetic resonance imaging and drug delivery. Here, SPIONs were prepared by optimized co-precipitation of iron chlorides in basic medium and then coated with gold. Bare SPIONs and Au-coated SPIONs were characterized by TEM before incubation with fetal bovine serum for 0.5, 1, 2, 4, 8 and 24 h. After these interaction times, the mixture was deposed on a small column in a strong magnetic field (MACS�®system). The SPIONs were retained; different washing fractions were collected and studied by UV-Vis spectroscopy and by 1D gel electrophoresis. The study revealed the presence of proteins in the washing solutions and confirmed the strong interaction of the protein with the SPIONs.