The controlled biofabrication of stable, aligned collagen hydrogels within microfluidic devices is critically important to the design of more physiologically accurate, longer-cultured on-chip models of tissue and organs. To address this goal, collagen-alginate microgels were formed in a microfluidic channel by calcium crosslinking of a flowing collagen-alginate solution through a cross-channel chitosan membrane spanning a pore allowing ion diffusion but not convection. The gels formed within seconds as isolated islands in a single channel, and their growth was self-limiting. Total gel thickness was controlled by altering the concentration of calcium and collagen-alginate flow rate to reach an equilibrium of calcium diffusion and solution convection at the gel boundary, for a desired thickness of 30–200 μ m. Additionally, less calcium and higher flow produced greater compression of the gel, with regions farther from the pore compressing more. An aligned, stable collagen net...

中文翻译：

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使用流动驱动共沉积和离子凝胶化微流控制备具有对齐微结构的稳定胶原微凝胶

微流体装置内稳定、对齐的胶原水凝胶的受控生物制造对于设计更生理准确、培养时间更长的组织和器官芯片模型至关重要。为了实现这一目标，通过跨通道壳聚糖膜流动的胶原-海藻酸盐溶液的钙交联在微流体通道中形成胶原-海藻酸盐微凝胶，该跨通道壳聚糖膜跨越允许离子扩散但不对流的孔。凝胶在几秒钟内形成单一通道中的孤立岛，并且它们的生长是自我限制的。通过改变钙的浓度和胶原蛋白-藻酸盐的流速来控制总凝胶厚度，以在凝胶边界达到钙扩散和溶液对流的平衡，以获得 30-200 μ m 的所需厚度。此外，更少的钙和更高的流量产生更大的凝胶压缩，离孔隙越远的区域压缩更多。排列整齐、稳定的胶原蛋白网...