Synthesis and characterization of poly(lactic acid)-modified superparamagnetic iron oxide nanoparticles

Poly(ethylene glycol) (PEG)- and poly(vinylpyrrolidone) (PVP)-coated superparamagnetic iron oxide nanoparticles (SPIONs) with the particle size of 8.0 +/- A 1.4 nm were synthesized by thermal decomposition of Fe(acac)(3) in 15 g PEG containing 0.3 g PVP (PEG/PVP-SPIONs) and then were coated further with poly(lactic acid) (PLA/PEG/PVP-SPIONs). The PEG/PVP-SPIONs and PLA/PEG/PVP-SPIONs were superparamagnetic with the saturation magnetization of 54.5 and 46.2 emu/g measured by the superconducting quantum interference device, respectively. The hydrodynamic diameter of PEG/PVP-SPIONs in deionized water was 18.8 nm, which increased to 52.4 nm after coated with PLA. The zeta potential of PEG/PVP-SPIONs was 0 mV, which changed to -11.3 mV after coated with PLA. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses indicated that PLA was attached to the PEG/PVP-SPIONs. Thermogravimetric analyses showed that the amount of PLA coated on PEG/PVP-SPIONs was about 9.6 wt%. With high magnetic properties and good dispersibility in aqueous media, the uniform-sized PLA/PEG/PVP-SPIONs nanoparticles have potential in biomedical application. [GRAPHICS] .