Xu Xuejiao, Appel Eric A, Liu Xin, Parker Richard M, Scherman Oren A, Abell Chris
Department of Chemistry and ‡Melville Laboratory for Polymer Synthesis, Department of Chemistry, University of Cambridge , Lensfield Road, Cambridge CB2 1EW, United Kingdom.
Biomacromolecules. 2015 Sep 14;16(9):2743-9. doi: 10.1021/acs.biomac.5b01048. Epub 2015 Aug 28.
Herein we describe the use of microdroplets as templates for the fabrication of uniform-sized supramolecular hydrogel beads, assembled by supramolecular cross-linking of functional biopolymers with the macrocyclic host molecule, cucurbit[8]uril (CB[8]). The microdroplets were formed containing diluted hydrogel precursors in solution, including the functional polymers and CB[8], in a microfluidic device. Subsequent evaporation of water from collected microdroplets concentrated the contents, driving the formation of the CB[8]-mediated host-guest ternary complex interactions and leading to the assembly of condensed three-dimensional polymeric scaffolds. Rehydration of the dried particles gave monodisperse hydrogel beads. Their equilibrium size was shown to be dependent on both the quantity of material loaded and the dimensions of the microfluidic flow focus. Fluorescein-labeled dextran was used to evaluate the efficacy of the hydrogel beads as a vector for controlled cargo release. Both passive, sustained release (hours) and triggered, fast release (minutes) of the FITC-dextran was observed, with the rate of sustained release dependent on the formulation. The kinetics of release was fitted to the Ritger-Peppas controlled release equation and shown to follow an anomalous (non-Fickian) transport mechanism.
在此，我们描述了使用微滴作为模板来制备尺寸均匀的超分子水凝胶珠，该水凝胶珠由功能性生物聚合物与大环主体分子葫芦[8]脲（CB[8]）通过超分子交联组装而成。微滴在微流控装置中形成，其中含有溶液中的稀释水凝胶前体，包括功能性聚合物和CB[8]。随后，收集到的微滴中的水分蒸发，使内容物浓缩，促使形成CB[8]介导的主客体三元复合相互作用，并导致凝聚的三维聚合物支架的组装。干燥颗粒再水化后得到单分散的水凝胶珠。结果表明，它们的平衡尺寸取决于加载的材料量和微流控流动聚焦的尺寸。用荧光素标记的葡聚糖来评估水凝胶珠作为可控载药释放载体的功效。观察到FITC-葡聚糖的被动、持续释放（数小时）和触发、快速释放（数分钟），持续释放速率取决于配方。释放动力学符合Ritger-Peppas控释方程，并表明遵循反常（非菲克）传输机制。
