摘要
制备了一系列pH敏感的壳聚糖衍生物,N-辛基-N′（-2-羧基环己甲酰基）-壳聚糖（OCCC）。并用FTIR,1HNMR、元素分析、DSC和XRD对载体理化性质进行了表征,MTT法测定了载体的细胞毒,OCCC包载了难溶性抗癌药物紫杉醇并对载体和载药胶束的pH敏感性进行了研究。芘荧光法测定载体的临界胶束浓度（CMC）为11-72μg/mL,紫杉醇胶束的载药量和包封产率分别为30.47%-48.10%,42.22%-59.24%。细胞毒研究表明载体几乎无毒。pH敏感性研究表明载体和胶束在正常生理环境下能保持稳定,而在微酸性环境（pH 5.5）中时敏感。
A series of pH-sensitive graft copolymers,N-octyl-N-（2-carboxyl-cyclohexamethenyl） chitosan derivatives have been synthesized and characterized by FTIR,1HNMR and elemental analysis,and their physical properties were measured with differential scanning calorimetry and X-ray diffraction spectrometry.The critical micelle concentrations（CMCs） of the modified chitosan determined by using pyrene as a hydrophobic probe in fluorescence spectroscopy were from 11 to 57 μg/mL.The graft polymers can form micelles solubilizing paclitaxel,with drug-loading rate ranging from 30.47% to 48.10% and entrapment effciency from 42.22% to 59.24%.Cytotoxicities of carrier against tumor cells estimated that carriers were nearly non-cytotoxic.Additionally,the results of pH-sensitivity and drug release experiments showed that the micelles were highly sensitive to mild acidic conditions（pH 5.5） while reasonably stable at physiological conditions（pH 7.4）.Therefore,chitosan-derived micelle may be a potential anti-tumor drug delivery system for chemotherapy of cancer.
基金
高等学校博士学科点专项科研基金资助项目(20070316004)
