Fibrous proteins found in the natural extracellular matrix (ECM) function as host substrates for migration and growth of endogenous cells during wound healing and tissue repair processes. Although various fibrous scaffolds have been developed to recapitulate the microstructures of the native ECM, facile synthesis of hydrogel microfibers that are mechanically robust and biologically active have been elusive. Described herein is the use of interfacial bioorthogonal polymerization to create hydrogel-based microfibrous scaffolds via tetrazine ligation. Combination of a trifunctional strained trans-cyclooctene monomer and a difunctional s-tetrazine monomer at the oil-water interface led to the formation of microfibers that were stable under cell culture conditions. The bioorthogonal nature of the synthesis allows for direct incorporation of tetrazine-conjugated peptides or proteins with site-selectively, genetically encoded tetrazines. The microfibers provide physical guidance and biochemical signals to promote the attachment, division and migration of fibroblasts. Mechanistic investigations revealed that fiber-guided cell migration was both F-actin and microtubule-dependent, confirming contact guidance by the microfibers. Prolonged culture of fibroblasts in the presence of an isolated microfiber resulted in the formation of a multilayered cell sheet wrapping around the fiber core. A fibrous mesh provided a 3D template to promote cell infiltration and tissue-like growth. Overall, the bioorthogonal approach led to the straightforward synthesis of crosslinked hydrogel microfibers that can potentially be used as instructive materials for tissue repair and regeneration.

中文翻译：

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细胞与通过界面四嗪连接合成的水凝胶微纤维的相互作用。

天然细胞外基质 (ECM) 中发现的纤维蛋白在伤口愈合和组织修复过程中充当内源细胞迁移和生长的宿主底物。尽管已经开发出各种纤维支架来概括天然 ECM 的微观结构，但机械坚固且具有生物活性的水凝胶微纤维的简便合成一直难以实现。本文描述的是使用界面生物正交聚合通过四嗪连接创建基于水凝胶的微纤维支架。三官能应变反式环辛烯单体和双官能s-四嗪单体在油-水界面处的组合导致形成在细胞培养条件下稳定的微纤维。合成的生物正交性质允许将四嗪缀合的肽或蛋白质与位点选择性的、基因编码的四嗪直接结合。微纤维提供物理引导和生化信号，促进成纤维细胞的附着、分裂和迁移。机制研究表明，纤维引导的细胞迁移既依赖于 F-肌动蛋白，又依赖于微管，证实了微纤维的接触引导。在分离的微纤维存在下长期培养成纤维细胞导致形成包裹纤维芯的多层细胞片。纤维网提供了 3D 模板来促进细胞浸润和组织样生长。总体而言，生物正交方法导致了交联水凝胶微纤维的直接合成，该纤维有可能用作组织修复和再生的指导材料。