Synthesis and characterization of a novel MPEG-chitosan diblock copolymer and self-assembly of nanoparticles

In this paper, a simple and novel method based on free-radical polymerization initiated by potassium persulfate (KPS) was developed to synthesize the MPEG-chitosan diblock copolymer (MPEG-CS). The obtained MPEG-CS diblock copolymer was characterized by Fourier transform infrared (FTIR),H-1 nuclear magnetic resonance (H-1 NMR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC), respectively. The MPEG-CS copolymer could self-assemble into nanoparticles in aqueous solution. A typical TEM photography indicated that the well-spherical nanoparticles with diameter at about 200 nm were obtained. In vitro cell culture assay indicated that MPEG-CS nanoparticles are non-toxic and cell-compatible as the polymer concentration was smaller than 0.6 mg/ml. In conclusion, the obtained MPEG-CS nanoparticles might have great potential application in drug-delivery system. (C) 2009 Elsevier Ltd. All rights reserved.