聚乳酸微胶囊的层层自组装及表征

Preparation and Characterization of Poly(lactic acid)Microcapsules by Layer-by-Layer Self-Assembly Method

以碳酸钠和氯化钙为原料制备的碳酸钙微球为模板,采用层层自组装的方法,将左旋聚乳酸(PLLA)和右旋聚乳酸(PDLA)逐层组装在碳酸钙微球上,然后用乙二胺四乙酸二钠(EDTA)去除模板碳酸钙后成功制备了聚乳酸中空微胶囊,并采用扫描电镜、原子力显微镜、透射电子显微镜、激光共聚焦显微镜、差示扫描量热仪和广角X射线衍射仪对微胶囊进行初步表征。结果表明,微胶囊层形成的层间驱动力为聚乳酸异构体之间的立构复合作用,微胶囊呈现经典的褶皱状,囊壁厚度约为90~100nm,内部为空腔结构,囊壁允许小分子物质透过,在载药缓释领域具有很好的应用前景。

Poly（lacticacid）（PLA） microcapsules were fabricated by layer-by-layer self-assembly of poly （L-lactic acid） （PLLA） and poly（D-lactic acid）（PDLA） onto the CaCO3 templates which were synthesized from Na2CO3 and CaCl2, followed by removing CaCO3 templates using ethylene diamine tetraacetic acid （EDTA）. The microcapsules were characterized by SEM, AFM, TEM, CLSM, DSC, and XRD. The results show that the interlayer driving force of microcapsules is the stereocomplex affection between PLA isomers. The morphology of microcapsule displays classical drape. The thickness of microcapsule wall is between 90nm and 100 nm, and the small molecules can pass through the wall. Therefore, the prepared capsules have potential application in the field of drug sustained releasing.