壳聚糖涂层聚乳酸细胞微载体的制备和性能

Chitosan-modified polylactide microspheres:potentially injectable cell carriers for tissue engineering

采用氨解技术在聚乳酸微球表面引入自由氨基,再利用戊二醛将氨基转化为醛基,最后采用接枝 涂层技术将壳聚糖固定到聚乳酸微球表面,制备了壳聚糖表面改性的聚乳酸细胞微载体．分别采用茚三酮 法和乙酰丙酮-对二甲氨基苯甲醛法测定了聚乳酸微球表面的氨基和壳聚糖含量．发现氨基的量初始随氨 解时间的延长而增大,达到最大(2．94×10-7mol／mg)后保持不变．与空白聚乳酸微球相比,软骨细胞在 壳聚糖改性聚乳酸微球表面能够更有效地粘附和生长,分布更为均匀．

Chitosan-modified polylactide （PLA） microspheres were fabricated by combination of surface aminolysis and subsequent grafting-coating methods. The PLA microspheres were treated firstly by 1,6-hexanediamine to introduce free amino groups on their surfaces. Ninhydrin analysis found that the introduced amount of the amino groups increased along with the prolongation of aminolysis time in the first few minutes, then reached to a maximum value that was up to 0.29 micromol per milligram spheres. After transferred the amino groups into aldehyde groups by glutaraldehyde treatment, chitosan was covalently grafted and physically coated onto the surfaces of the PLA microspheres. Acetylactone-dimethylaminobenzaldehyde analysis found that the introduced amount of the chitosan was 3.34 microgram per milligram spheres. In vitro chondrocyte culture revealed that the cells could attach and grow better on the PLA microspheres having chitosan molecules. These results demonstrate that the PLA microspheres coated with chitosan are promising microcarriers for cell culture and potential injectable cell carriers.