Department of Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan.
Biomed Microdevices. 2010 Feb;12(1):125-33. doi: 10.1007/s10544-009-9367-8.
We have successfully demonstrated the formation of biodegradable microcapsules utilizing PDMS double-emulsification devices. Specially designed 3D PDMS microchannels with surfaces selectively modified by a self-aligned photografting process are employed to generate monodisperse water-in-organic-solvent-in-water (W/O/W) emulsions in a controlled manner. Mainly by varying the outer and inner fluid flow-rates, the dimensions of resulting double emulsions can be adjusted as desired. Meanwhile, biodegradable materials are dissolved in the middle organic solvent (in this work ethyl acetate is used), and solidified into microcapsules once the solvent is extracted. In the prototype demonstration, microcapsules made up of poly(L-lactic acid), trilaurin, and phosphocholine were successfully fabricated. In addition, it was also demonstrated that gamma-Fe(2)O(3) nanoparticles can be simultaneously embedded into the microcapsules, which consequently become responsive to electromagnetic stimulation. As such, the presented PDMS microfluidic devices could potentially serve as versatile encapsulation apparatus, and the fabricated biodegradable microcapsules could function as controlled delivery systems, which are desired for a variety of biological and pharmaceutical applications.
我们成功地利用 PDMS 双乳液装置制备了可生物降解的微胶囊。特别设计的具有 3D PDMS 微通道的表面通过自对准光接枝过程进行选择性修饰，以可控的方式生成单分散的水包有机相包水（W/O/W）乳液。主要通过改变外相和内相的流速，可以按需调整所得的双乳液的尺寸。同时，可生物降解的材料溶解在中间有机溶剂（在本工作中使用乙酸乙酯）中，一旦溶剂被提取，就会固化成微胶囊。在原型演示中，成功制备了由聚（L-乳酸）、三硬脂酸甘油酯和磷酰胆碱组成的微胶囊。此外，还证明了γ-Fe(2)O(3)纳米粒子可以同时嵌入微胶囊中，从而使微胶囊对电磁刺激产生响应。因此，所提出的 PDMS 微流控装置可以作为通用的封装设备，所制备的可生物降解微胶囊可以作为控释系统，这是各种生物和制药应用所需要的。
