Department of Chemical Engineering, McMaster University, 1280 Main St. W., Hamilton, Ontario, L8S 4L7, Canada.
Small. 2012 Apr 10;8(7):1092-8. doi: 10.1002/smll.201102113. Epub 2012 Feb 22.
The development of a robust method for the synthesis of highly monodisperse microgels cross-linked with degradable covalent bonds offers the potential for fabricating microgels with the highly controllable porosities, cell interactions, and degradation half-lives required for biomedical applications. A microfluidic chip is designed that enables the on-chip mixing and emulsification of two reactive polymer solutions (hydrazide and aldehyde-functionalized carbohydrates) to form monodisperse, hydrazone cross-linked microgels in the size range of ≈40-100 μm. The device can be run continuously for at least 30 h without a significant drift in particle size. The resulting microgels have a homogeneous bulk composition and can swell and deswell as the solvent conditions change in predictable ways based on the chemistry of the reactive polymers used, thereby enabling improved control over both the chemistry and morphology of the resulting microgels relative to other reported approaches. The in situ gelation chemistry used facilitates rapid microgel formation within the droplets without requiring the use of UV light or heating to initiate polymerization, thus making this approach of particular potential utility in cell encapsulation or drug delivery (as demonstrated).
开发一种用于合成高度单分散性微凝胶的稳健方法，交联键可降解的共价键，为制造具有高度可控孔隙率、细胞相互作用和降解半衰期的微凝胶提供了可能，这些性质是生物医学应用所必需的。设计了一种微流控芯片，可实现在芯片上混合和乳化两种反应性聚合物溶液（酰腙和醛基功能化碳水化合物），形成尺寸约为 ≈40-100 μm 的单分散性腙键交联微凝胶。该设备可以连续运行至少 30 h，而粒径没有明显漂移。所得微凝胶具有均匀的体相组成，并且可以根据所用反应性聚合物的化学性质以可预测的方式溶胀和收缩，从而相对于其他报道的方法，能够更好地控制所得微凝胶的化学性质和形态。所使用的原位凝胶化化学促进了在液滴内的快速微凝胶形成，而不需要使用紫外线或加热来引发聚合，因此，这种方法在细胞包封或药物传递（如所证明的）中具有特别的潜在用途。
