Journal of Polymer Science Part A: Polymer Chemistry, Vol.50, No.23, 4936-4946, 2012
Synthesis of Well-Defined Chitosan-Based Tricomponent Copolymers for Constructing Multifunctional Delivery Systems
Chitosan-based tricomponent copolymers, chitosan-g-poly(e-caprolactone)-(g-poly(oligo(ethylene glycol) methacrylate)) (CS-PCL-POEGMA, CPP), are synthesized as multifunctional nanocarriers for antitumor therapy. 2-Bromoisobutyric acid and PCL are first site-specifically conjugated onto the hydroxy groups of chitosan backbone through conventional coupling chemistry to give CS-PCL-Br using sodium dodecyl sulfatechitosan complex as an organosoluble intermediate. CPP-PCL-Br is further used for initiating the single electron transfer-living radical polymerization of OEGMA in the mixed solvent of dimethyl sulfoxide and lactic acid, yielding CPP. One-pot reaction of CPP with a small amount of NaN3 under the catalysis of Cu(I)Br/tris-(2-dimethylaminoethyl)amine converts the bromo ends of POEGMA grafts to azide functionality, which is used for conjugation of folic acid targeting moiety via azide-alkyne click reactions. The resultant tricomponent copolymers can assemble into spherical micelles with the capacity of coincorporating indocyanine green and Doxorubicin through electrostatic and hydrophobic interactions, respectively. The dual-agent-loaded micelles display a combined effect for combating HepG2 cells when irradiated with near-infrared laser. (C) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 50: 4936-4946, 2012
Keywords:chitosan;click chemistry;combination therapy;micelles;single electron transfer-living radical polymerization (SET-LRP)