Microfluidic fabrication of monodisperse polylactide microcapsules with tunable structures through rapid precipitation.
Microfluidic fabrication of monodisperse polylactide microcapsules with tunable structures through rapid precipitation.
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DOI：
10.1021/la403883a
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发表时间：
2013-11
期刊：
影响因子：
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通讯作者：
Takaichi Watanabe;Y. Kimura;T. Ono
中科院分区：
文献类型：
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作者：
Takaichi Watanabe;Y. Kimura;T. Ono
我们描述了一个通用的和简便的路线，连续生产单分散聚乳酸（PLA）微胶囊的可控结构。采用微流控乳化、溶剂扩散和内相分离相结合的方法，通过简单的纯水稀释单分散乙酸乙酯（EA）水包乳液，成功地制备了以全氟辛基溴（PFOB）为核的均匀聚乳酸微胶囊。EA从液滴到水相中的快速提取使得在浓缩的PLA/EA相和PFOB相之间的内部相分离期间聚合物液滴在非平衡状态下固化。较高分子量的聚乳酸产生的微胶囊的结构复杂性，产生核壳微胶囊覆盖着小的PFOB液滴。通过冷冻干燥除去PFOB得到具有凹陷表面的中空微胶囊。微胶囊的粒径和核壳比可以通过调节PFOB的浓度和乳化液的流速来调节。这些尺寸和结构可控的生物相容性微胶囊在生物医学领域具有潜在的应用前景，如许多功能分子的药物递送载体。
We describe a versatile and facile route to the continuous production of monodisperse polylactide (PLA) microcapsules with controllable structures. With the combination of microfluidic emulsification, solvent diffusion, and internal phase separation, uniform PLA microcapsules with a perfluorooctyl bromide (PFOB) core were successfully obtained by simply diluting monodisperse ethyl acetate (EA)-in-water emulsion with pure water. Rapid extraction of EA from the droplets into the aqueous phase enabled the solidification of the polymer droplets in a nonequilibrium state during internal phase separation between a concentrated PLA/EA phase and a PFOB phase. Higher-molecular-weight PLA generated structural complexity of the microcapsules, yielding core-shell microcapsules with covered with small PFOB droplets. Removal of the PFOB via freeze drying gave hollow microcapsules with dimpled surfaces. The core-shell ratios and the diameter of these microcapsules could be finely tuned by just adjusting the concentration of PFOB and flow rates on emulsification, respectively. These biocompatible microcapsules with controllable size and structures are potentially applicable in biomedical fields such as drug delivery carriers of many functional molecules.