Effects of PEG length and iron oxide nanoparticles size on reduced protein adsorption and non-specific uptake by macrophage cells.

At present, the studies showed that applications of magnetic iron oxide nanoparticels in vivo are hampered by their non-specific uptake by the innate immune system. And surface PEGylation of the nanoparticles maybe a feasible approach to escape from the reticular-endothelial system for a long blood circulation half-life. In this paper, we synthesized two sizes of monodisperse nanoparticles and studied the effects of PEG length on reduced protein adsorption and non-specific uptake by macrophage cells for an ideal material with a relatively long blood half-life. The results show that small nanoparticles with high molecular weight PEGylation may be a more applicable candidate due to their size effect and high efficiency in reducing protein adsorption.