生物素化胆甾醇基普鲁兰糖合成及其自聚集性质

Synthesis of biotin modified cholesteryl pullulan and its self-aggregated behavior

通过酯化反应将生物素接枝于胆甾醇基普鲁兰糖链上,获得不同取代度的生物素化胆甾醇基普鲁兰糖(Bio-CHSP)衍生物.采用氢核磁(1 H NMR)和X线粉末衍射法(XRD)共同验证Bio-CHSP材料的成功合成,并用1 H NMR法确定Bio-CHSP的生物素取代度.Bio-CHSP改性材料具有两亲性,透射电镜(TEM)显示,可在水中自聚集成球型纳米粒.动态激光粒度分析仪(DLS)测定表明,Bio-CHSP纳米粒带负电荷且粒径随生物素取代度增大而减小.以芘为荧光探针,采用稳态荧光法测定Bio-CHSP纳米粒水溶液的临界聚集浓度(CAC),其CAC随生物素取代度的增大而减小.Bio-CHSP材料在水中表现出良好的自聚集特性,有望成为一种新型抗肿瘤药物的纳米载体.

The biotin modified cholesteryl pullulan （Bio-CHSP） was prepared by the esterification reaction of biotin and cholesteryl pullulan （CHSP） in DMSO. The structure of Bio-CHSP was confirmed by the X- ray diffraction （XRD） and proton nuclear magnetic resonance （1 H NMR）, and the degree of substitution （DS） of biotin moiety was determined by 1H NMR. Bio-CHSP self-aggregated nanoparticles （Bio-CHSP NPs） were prepared by the dialysis method, analyzed by dynamic light-scattering （DLS）, zeta potential, transmission electron microscopy（TEM） and their self-aggregated behavior in aqueous solution were evalu- ated by fluorescence probe technologies. The results of the experiment showed that Bio-CHSP with differ- ent DS of biotin moieties was successfully synthesized and the polymer could self-aggregate to form spheri- cal nanoparticles. The zeta potential was negative, their sizes and critical aggregation concentration （CAC） were decreased with the increasing of DS. Bio-CHSP polymer showed a good self-aggregation behavior in water, therefore, Bio-CHSP was a promising potential as a novel nanometer carrier for antitumor drugs.