Biocompatible superparamagnetic iron oxide nanoparticle dispersions stabilized with poly(ethylene glycol)-oligo(aspartic acid) hybrids

摘要

Methoxypoly(ethylene glycol)-oligo(aspartic acid) (MPEG-Asp_n-NH_2, n = 2-5) hybrid block copolymers were synthesized and used as stabilizers to prepare superparamagnetic Fe_3O_4 nanoparticles with magnetite as the inner core and and poly(ethylene glycol) as the hydrophilic outer shell. The aqueous dispersions of the nanoparticles were stable at pH 2-11 and in 1M NaCl solution, when repeat number, n, was 3 or more. Transmission electron microscopy showed that the nanoparticles, stabilized with MPEG-Asp_3-NH_2, were about 14 nm in diameter. Magnetic measurements indicated that MPEG-Asp_3-NH_2-coated iron oxide nanoparticles showed superparamagnetic behavior. Cell adhesion assay and in vitro cell viability/cytotoxicity studies showed that MPEG-Asp_3-NH_2-coated iron oxide nanoparticles had less effect on cell adhesion/viability and morphology, and less cytotoxicity compared with uncoated, poly (acrylic acid)-coated, and MPEG-poly(acrylic acid)-coated iron oxide nanoparticles.