Zhang Hong, Tumarkin Ethan, Peerani Raheem, Nie Zhihong, Sullan Ruby May A, Walker Gilbert C, Kumacheva Eugenia
Department of Chemistry, University of Toronto, 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada.
J Am Chem Soc. 2006 Sep 20;128(37):12205-10. doi: 10.1021/ja0635682.
We report a microfluidic approach to generating capsules of biopolymer hydrogels. Droplets of an aqueous solution of a biopolymer were emulsified in an organic phase comprising a cross-linking agent. Polymer gelation was achieved in situ (on a microfluidic chip) by diffusion-controlled ionic cross-linking of the biopolymer, following the transfer of the cross-linking agent from the continuous phase to the droplets. Gelation was quenched by collecting particles in a large pool of cross-linking agent-free liquid. The structure of microgels (from capsules to gradient microgels to particles with a uniform structure) was controlled by varying the time of residence of droplets on the microfluidic chip and the concentration of the cross-linking agent in the continuous phase. We demonstrated the encapsulation of a controlled number of polystyrene beads in the microgel capsules. The described approach was applied to the preparation of capsules of several polysaccharides such as alginate, kappa-carrageenan, and carboxymethylcellulose.
我们报道了一种用于生成生物聚合物水凝胶胶囊的微流控方法。生物聚合物水溶液的液滴在包含交联剂的有机相中乳化。通过交联剂从连续相转移到液滴后，生物聚合物的扩散控制离子交联在原位（在微流控芯片上）实现聚合物凝胶化。通过将颗粒收集在大量无交联剂的液体中来终止凝胶化。通过改变液滴在微流控芯片上的停留时间以及连续相中交联剂的浓度来控制微凝胶的结构（从胶囊到梯度微凝胶再到具有均匀结构的颗粒）。我们展示了在微凝胶胶囊中封装可控数量的聚苯乙烯珠粒。所描述的方法被应用于制备几种多糖（如藻酸盐、κ-卡拉胶和羧甲基纤维素）的胶囊。
