Surface-Initiated Polymerization of 2-Hydroxyethyl Methacrylate from Heterotelechelic Oligoperoxide-Coated γ-Fe2O3 Nanoparticles and their Engulfment by Mammalian Cells

摘要

Novel heterotelechelic poly(N-vinylpyrrolidone) (CPA-PVP-IBMB) oligoperoxide containing anchoring carboxyl group from 4-cyanopentanoic acid (CPA) and peroxide end-group from l-isopropyl-3(4)-l-(tert-butyl peroxy)-l-methylethyl benzene (IBMB) chain transfer agent was synthesized and investigated as a surface-active macroinitiator for tailored functionalization of maghemite (γ-Fe2O3) nanoparticles. CPA-PVP-IBMB initiated polymerization of 2-hydroxyethyl methacrylate (HEMA) in ethanol yielding CPA-PVP-block-poly (2-hydroxyethyl methacrylate) (CPA-PVP-block-PHEMA) copolymer. γ-Fe2O3 nanoparticles obtained by precipitation technique were modified by the CPA-PVP-IBMB macroinitiator and CPA-PVP-block-PHEMA copolymer by "grafting-to" approach to the surface using carboxyl end groups of both polymers. Second method, "grafting-from" approach, consisted in polymerization of HEMA initiated from the surface of CPA-PVP-IBMB-coated y-Fe2O3 nanoparticles yielding CPA-PVP-IBMB-coated y-Fe2O3/PHEMA nanoparticles. Tests with mice leukemia L1210 cells confirmed nontoxicity of CPA-PVP-IBMB-coated y-Fe2O3/PHEMA nanoparticles. CPA-PVP-IBMB-coated y-Fe2O3/PHEMA nanoparticles were easily engulfed by murine macrophages J774.2 and magnetically separated from cells without phagocytic activity.