Preparation and characterization of antifouling thermosensitive magnetic nanoparticles for applications in biomedicine

Copolymer brushes grafting onto magnetic nanoparticles (MNPs) were prepared via surface free radical polymerization to improve antifouling properties of thermosensitive MNPs. A chain transfer agent was firstly attached to MNPs by silanization. Copolymerization of poly(ethylene glycol) monomethacrylate and N-isopropylacrylamide was then conducted to graft polymer brushes on the particles surface via surface free radical polymerization. The lower critical solution temperature of the obtained thermosensitive MNPs is 43 °C, which is higher than that of homopolymer poly(N-isopropylacrylamide). Nonspecific adsorption of protein was resisted at room temperature and 45 °C. The result suggested that poly(ethylene glycol) monomethacrylate segments decrease nonspecific adsorption of protein above LCST.