【摘要】 研究了壳聚糖及其衍生物的修饰对pH敏感型聚乳酸-羟基乙酸(PLGA)微粒性质及其在巨噬细胞中分布的影响.通过微孔膜乳化技术与复乳溶剂挥发法相结合制备了壳聚糖及其衍生物修饰的pH敏感型PLGA微粒,用单因素法对pH敏感型PLGA微粒的制备工艺进行了优化,以Bradford protein assay法测定微粒的蛋白含量,用扫描电子显微镜观察了微粒的形态结构,用马尔文粒径仪测定了微粒的粒径和zeta电位,用台盼蓝染色法测定了微粒的细胞毒性,并利用荧光标记法确定了微粒在巨噬细胞内的分布.结果发现,4种微粒粒径为1 000～1 200 nm;壳聚糖及其衍生物修饰后的微粒包封率明显上升,zeta电位显著升高,壳聚糖修饰的微粒主要分布在细胞质,而未被修饰的微粒主要分布在溶酶体内.更多还原

【Abstract】 This study investigated the effect of surface modification with chitosan and its derivatives on the characteristics of pH-sensitive poly(lactic-co-glycolic acid)(PLGA) microparticles and their distribution in macrophages.By combination of microporous shirasu porous glass and double emulsion-solvent evaporation method,the pH-sensitive PLGA microparticles modified by chitosan and its derivatives were prepared.The single factor method was used to optimize the preparation of pH-sensitive PLGA microparticles.The protein content of the microparticles was determined by Bradford assay.The morphological structure of the microparticles was observed with a scanning electron microscope.The particle size and zeta potential of the microspheres were measured with a Malvern particle size analyzer and the cytotoxicity of the microparticles was determined by trypan blue staining.The distribution of the microparticles within macrophages was determined by a fluorescent labeling method.The results showed that the size of four kinds of particles was 1 000～1 200 nm.Compared with unmodified microparticles,entrapment efficiency and zeta potential of the microparticles modified with chitosan and its derivatives significantly increased.The microparticles modified with chitosan distributed primarily in cytoplasm,whereas the unmodified microparticles mainly distributed in lysosomes.更多还原