Zhao Qinghe, Mao Zhengwei, Gao Changyou, Shen Jiacong
Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China.
J Biomater Sci Polym Ed. 2006;17(9):997-1014. doi: 10.1163/156856206778366031.
Multilayer microcapsules were fabricated by layer-by-layer (LbL) assembly of natural polysaccharides onto CaCO3 particles, following with core removal. The micron-sized CaCO3 particles were synthesized by reaction between Ca(NO3)2 and Na2CO3 solutions in the existence of carboxylmethyl cellulose (CMC). The incorporated amount of CMC in the CaCO3 particles was found to be 5.3 wt% by thermogravimetric analysis. Two biocompatible polysaccharides, chitosan and sodium alginate were alternately deposited onto the CaCO3(CMC) templates to obtain hollow microcapsules. Regular oscillation of surface charge as detected by zeta potential demonstrated that the assembly proceeded surely in a LbL manner. The stability of the microcapsules was effectively improved by cross-linking of chitosan with glutaraldehyde. The chemical reaction was verified by infrared spectroscopy. The microcapsules thus fabricated could be spontaneously filled with positively charged low molecular weight substances such as rhodamine 6G and showed good biocompatibility, as detected by in vitro cell culture.
通过将天然多糖逐层（LbL）组装到碳酸钙颗粒上，随后去除核心，制备了多层微胶囊。微米级碳酸钙颗粒是在羧甲基纤维素（CMC）存在下，由硝酸钙和碳酸钠溶液反应合成的。通过热重分析发现，碳酸钙颗粒中CMC的掺入量为5.3 wt%。将两种生物相容性多糖壳聚糖和海藻酸钠交替沉积到碳酸钙（CMC）模板上，以获得中空微胶囊。通过zeta电位检测到的表面电荷的规则振荡表明，组装确实以LbL方式进行。壳聚糖与戊二醛交联有效地提高了微胶囊的稳定性。通过红外光谱验证了化学反应。如此制备的微胶囊可以自发地填充带正电荷的低分子量物质，如罗丹明6G，并且通过体外细胞培养检测显示出良好的生物相容性。
