School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China.
J Colloid Interface Sci. 2013 Aug 15;404:85-90. doi: 10.1016/j.jcis.2013.04.044. Epub 2013 May 7.
Monodisperse hollow and core-shell calcium alginate microcapsules are successfully prepared via internal gelation in microfluidic-generated double emulsions. Microfluidic emulsification is introduced to generate monodisperse oil-in-water-in-oil (O/W/O) double emulsion templates, which contain Na-alginate, CaCO3 nanoparticles, and photoacid generator in the middle aqueous phase, for synthesizing Ca-alginate microcapsules. The internal gelation of the aqueous middle layer of O/W/O double emulsions is induced by crosslinking alginate polymers with Ca(2+) ions that are released from CaCO3 nanoparticles upon UV exposure of the photoacid generator. The as-prepared hollow and core-shell calcium alginate microcapsules are highly monodisperse and spherical in water. Model proteins Bovine serum albumin (BSA) molecules can be encapsulated into the Ca-alginate microcapsules after the capsule preparation, which demonstrates an alternative route for loading active drugs or chemicals into carriers to avoid the inactivation during the carrier preparation. The proposed technique in this study provides an efficient approach for synthesis of monodisperse hollow or core-shell calcium alginate microcapsules with large cavity or encapsulated lipophilic drugs, chemicals, and nutrients.
通过在微流控生成的双乳液中进行内凝胶化，成功制备了单分散的中空和核壳海藻酸钠微胶囊。微流控乳化被引入以生成单分散的油包水包油（O/W/O）双乳液模板，其中包含中间水相中的 Na-海藻酸盐、CaCO3 纳米粒子和光酸产生剂，用于合成海藻酸钠微胶囊。O/W/O 双乳液的水中间层的内凝胶化是通过交联海藻酸盐聚合物与 Ca（2+）离子诱导的，CaCO3 纳米粒子在光酸产生剂的 UV 暴露下释放出 Ca（2+）离子。所制备的中空和核壳海藻酸钙微胶囊在水中具有高度单分散性和球形。在胶囊制备后，可以将牛血清白蛋白（BSA）等模型蛋白质包裹到 Ca-海藻酸盐微胶囊中，这为将活性药物或化学物质装入载体提供了一种替代途径，以避免在载体制备过程中失活。本研究中提出的技术为合成具有大空腔或包封疏水性药物、化学品和营养物的单分散中空或核壳海藻酸钠微胶囊提供了一种有效的方法。
