“…Mechanisms of preventing opsonization by PEG include the shielding of the surface charges, increased surface hydrophilicity (Gabizon & Papahadjopoulos, 1992), and enhanced repulsive interaction between polymer-coated nanoparticles and blood components (Needham et al, 1992). Various methods have been utilized to attach PEG to the MNP surface, including silane grafting to the oxide surface (Butterworth et al, 2001), alkaline coprecipitation of ferric and ferrous ions in the presence of PEG-containing block copolymers (Wan et al, 2005), direct attachment of PEG-containing block copolymers (Guo et al, 2010), polymerization at the MNP surface (Flesch et al, 2005), and modification through sol-gel approaches (Y. Lu et al, 2002).…”