Preparation, Characterization, and Self-assembly Behavior of a Novel MPEG/PCL-g-Chitosan Copolymer

Abstract

In this article, MPEG/PCL-g-Chitosan (MPEG/PCL-g-CS) was successfully prepared via free‐radical polymerization method. MPEG/PCL copolymer was first synthesized from MPEG and ϵ‐caprolactone. Then, the double bond ended MPEG/PCL (MPEG/PCL macromonomer) was obtained by reaction with acryloyl chloride at 40^oC in pre-dried dichloromethane. MPEG/PCL-g-CS copolymer was characterized by ¹H-nuclear magnetic resonance (¹H-NMR), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and differential scanning calorimeter (DSC), respectively. The obtained amphiphilic MPEG/PCL-g-CS copolymer could self-assemble into nanoparticles in aqueous solution. The critical micellar concentration (CMC) of MPEG/PCL-g-CS copolymer is about 1.78 mg/L determined by the fluorescence robe technique. In vitro cytotoxicity test revealed that MPEG/PCL-g-CS nanoparticles were low cytotoxicity against HEK293 cells after incubated for 24 h. The coupling of CS with MPEG/PCL endowed the pH sensitivity and cationic characteristics to MPEG/PCL nanoparticles. Size distribution and zeta potential of nanoparticles were greatly influenced by pH values.

Keywords:

• MPEG/PCL-g-Chitosan
• Nanoparticles
• Self-assembly

ACKNOWLEDGMENTS

This work was financially supported by National 863 project (2007AA021902), National Natural Science Foundation of China (NSFC30700996), Specialized Research Fund for the Doctoral Program of Higher Education (SRFDP 200806100065), New Century Excellent Talents in University (NCET-08-0371), and Chinese Key Basic Research Program (2010CB529906).