High-throughput double emulsion-based microfluidic production of hydrogel microspheres with tunable chemical functionalities toward biomolecular conjugation
High-throughput double emulsion-based microfluidic production of hydrogel microspheres with tunable chemical functionalities toward biomolecular conjugation
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DOI：
10.1039/c7lc01088e
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发表时间：
2018-01-21
期刊：
影响因子：
6.1
通讯作者：
Choi, Chang-Hyung
中科院分区：
文献类型：
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作者：
Liu, Eric Y.;Jung, Sukwon;Choi, Chang-Hyung
具有化学功能的水凝胶微球在生物传感、药物输送和组织工程等领域具有巨大的应用潜力，因为它们在赋予一系列功能方面具有高度的灵活性。在这项工作中，我们提出了一种简单、高效和高通量的毛细管微流控方法，通过形成以超薄油壳为牺牲模板的双乳滴来控制制备单分散和具有化学功能的水凝胶微球。这种方法利用聚合时油相的自发脱湿并转移到水溶液中，得到含有伯胺(壳聚糖，CS)或羧酸盐(丙烯酸，AA)的聚乙二醇基微球，以实现化学功能。对所制备的微球的简单荧光标记表明，微球中存在丰富、均匀分布且易于调节的官能团。此外，我们还通过与其他伯胺的直接比较，证明了壳聚糖伯胺在生理pH下作为一种有效的偶联手柄的作用，因为它的pKa很低。我们还报道了这些微球在模型荧光蛋白R-藻红蛋白(R-PE)和绿色荧光蛋白(GFPuv)的生物分子偶联中的应用，分别对CS-聚乙二醇微球通过四嗪-反式环辛烯(TCO)连接和对AA-聚乙二醇微球进行碳二亚胺化学连接。结果表明，R-PE与微球的官能团快速偶联，非特异性吸附最少。对我们的微球进行了深入的蛋白质结合动力学研究，突出了R-PE与CS-PEG微球和AA-PEG微球在反应和扩散方面的差异。最后，我们通过简单的基于大小的编码，展示了CS-PEG微球和AA-PEG微球与R-PE和GFPuv的正交一锅蛋白质偶联。总而言之，这些结果代表着快速、可靠地制备单分散、具有可调性能的化学功能水凝胶微球方面的重大进步。
Chemically functional hydrogel microspheres hold significant potential in a range of applications including biosensing, drug delivery, and tissue engineering due to their high degree of flexibility in imparting a range of functions. In this work, we present a simple, efficient, and high-throughput capillary microfluidic approach for controlled fabrication of monodisperse and chemically functional hydrogel microspheres via formation of double emulsion drops with an ultra-thin oil shell as a sacrificial template. This method utilizes spontaneous dewetting of the oil phase upon polymerization and transfer into aqueous solution, resulting in poly(ethylene glycol) (PEG)-based microspheres containing primary amines (chitosan, CS) or carboxylates (acrylic acid, AA) for chemical functionality. Simple fluorescent labelling of the as-prepared microspheres shows the presence of abundant, uniformly distributed and readily tunable functional groups throughout the microspheres. Furthermore, we show the utility of chitosan's primary amine as an efficient conjugation handle at physiological pH due to its low pKa by direct comparison with other primary amines. We also report the utility of these microspheres in biomolecular conjugation using model fluorescent proteins, R-phycoerythrin (R-PE) and green fluorescent protein (GFPuv), via tetrazine-trans-cyclooctene (Tz-TCO) ligation for CS-PEG microspheres and carbodiimide chemistry for AA-PEG microspheres, respectively. The results show rapid coupling of R-PE with the microspheres' functional groups with minimal non-specific adsorption. In-depth protein conjugation kinetics studies with our microspheres highlight the differences in reaction and diffusion of R-PE with CS-PEG and AA-PEG microspheres. Finally, we demonstrate orthogonal one-pot protein conjugation of R-PE and GFPuv with CS-PEG and AA-PEG microspheres via simple size-based encoding. Combined, these results represent a significant advancement in the rapid and reliable fabrication of monodisperse and chemically functional hydrogel microspheres with tunable properties.