| Based on the non-toxic,biodegradable and biocompatible of chitosan,in this paper, we synthesized a series of amphiphilic chitosan derivatives,and their self-assembled micelles and drug-loaded micelles were prepared.The characterization of polymeric micelles were studied by TEM,DLS and fluorescence spectroscopy;by adjusting the ratios of hydrophilic/hydrophobic segment length,the effcts of molecular weight of hydrophobic segment on the micelle size,CMC,drug loading capacity,drug loading efficiency and drug delivery behavior were studied;in addition,by introducing the groups which have temperature and pH-sensitive onto the chitosan chain,make the micelle have active targeting effects.The main contents are summarized as follows:1.The amphiphilic graft copolymer PHCS-g-PVP was synthesized.The copolymer can self-assembled to micelles in water,the micelle size is 89.8nm and its CMC value is 8.3×10-4mg/mL.After loading the hydrophobic drug,the result showed that the micelle have high drug-loading capacities(44.6wt%),high drug-loading efficiencies(80.6%) and exhibited a sustained drug release behavior.2.Amphiphilic graft copolymer composed of chitosan and carboxyl terminated poly (methyl methacrylate) having three various molecular weights was respectively synthesized.The micelles and PA-loaded micelles were prepared.The mean diameters of the micelles were from 23.20 to 132.03 nm and CMC of these micelles were in the range of 1×10-5 to1×10-4mg/mL.After incorporating PA into the micelles,the results indicated that all the three micelles have high drug-loading capacities(33.49-38.88wt%),high drug-loading efficiencies(52.88-60.78%) and exhibited sustained drug release.In all,the molecular weight of PMMA in the graft copolymers has a big influence on these properties.3.PHCS-g-PNIPAAm＆PAA copolymer was synthesized with dual grafts segment of PNIPAAm and PtBA.Their self-assembled micelle was prepared.The micelle not only have nano-size(94.1nm) and low CMC value(7.5×10-4mg/mL),but also has temperature-sensitive(the LCST is 30℃).After incorporating PA into the micelles,the results indicated that the micelle have high drug-loading capacity(24.70wt%),high drug-loading efficiency(27.71%).The drug releasebehavior showed that the micelle not only have sustained effect,but also have temperature and pH-sensitive.
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