交联壳聚糖水凝胶填充层状微胶囊的制备与性能

在甲基丙烯酸和乳酸接枝修饰的水溶性壳聚糖(CML)存在下, 合成了尺寸均匀的球形CML杂化碳酸钙微粒. 通过层层组装(LBL)技术在该微粒表面形成了聚苯乙烯磺酸钠(PSS)/聚烯丙基胺盐酸盐(PAH)多层膜, 去除碳酸钙微粒后得到内部含有CML的聚电解质微胶囊. 进一步采用紫外光引发CML聚合, 将CML转化为CML微凝胶, 得到内部填充凝胶的微胶囊. 通过扫描电镜、光学显微镜和透射电镜等技术表征了微胶囊的结构. 与传统的LBL微胶囊不同, 凝胶填充的微胶囊干燥时尺寸收缩, 但仍可保持球形; 再次水化后, 能够膨胀恢复其原有尺寸和形态. 各种具有不同电荷性质、分子量和亲疏水性的染料分子及蛋白质均可有效地装载到微胶囊内.

Fabrication and Properties of Chitosan Hydrogel Filled Multilayer Microcapsules

In a solution containing water soluble chitosan(CML) derivative which was obtained by grafting lactic acid and methacrylic acid, CaCO3 microparticles doped with the CMLCaCO3(CML)] were fabricated. Layer-by-layer assembly of polystyrene sulfonate sodium salt(PSS) and poly(allylamine hydrochloride)(PAH) was then conducted on the CaCO3(CML) microparticles to form core-shell particles. Core removed by disodium ethylenediaminetetraacetate dihydrate yielded the PSS/PAH multilayer microcapsules having the CML in their interiors. The CML hydrogel was formed in situ by a photoinduced crosslinking. The as-prepared microcapsules preserved the microscopic morphology of their template particles. Unlike the traditional multilayer microcapsules, these CML hydrogel filled microcapsules remained their spherical shape after drying, but their size was decreased from 6.8 μm to 4.6 μm. The capsule size and shape were recovered after hydration. These microcapsules showed a high loading efficiency of fluorescent dyes including negatively charged fluorescein and bovine serum albumin, positively charged rhodamine, and neutral Nile red in both water and organic solutions.