Current commercially available human skin equivalents (HSEs) are used for relatively short term studies (∼1 week) due in part to the time-dependent contraction of the collagen gel-based matrix and the limited cell types and skin tissue components utilized. In contrast, here we describe a new matrix consisting of a silk-collagen composite system that provides long term, stable cultivation with reduced contraction and degradation over time. This matrix supports full thickness skin equivalents which include nerves. The unique silk-collagen composite system preserves cell-binding domains of collagen while maintaining the stability and mechanics of the skin system for long-term culture with silk. The utility of this new composite protein-based biomaterial was demonstrated by bioengineering full thickness human skin systems using primary cells, including nerves and immune cells to establish an HSE with a neuro-immuno-cutaneous system. The HSEs with neurons and hypodermis, compared to in vitro skin-only HSEs controls, demonstrated higher secretion of pro-inflammatory cytokines. Proteomics analysis confirmed the presence of several proteins associated with inflammation across all sample groups, but HSEs with neurons had the highest amount of detected protein due to the complexity of the model. This improved, in vitro full thickness HSE model system utilizes cross-linked silk-collagen as the biomaterial and allows reduced reliance on animal models and provides a new in vitro tissue system for the assessment of chronic responses related to skin diseases and drug discovery.

中文翻译：

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3D 生物材料基质可支持具有神经系统组件的长期、全厚度、具有免疫功能的人体皮肤等效物。


目前市售的人类皮肤等效物 (HSE) 用于相对短期的研究（~1 周），部分原因是基于胶原凝胶的基质的时间依赖性收缩以及所使用的细胞类型和皮肤组织成分有限。相比之下，我们在这里描述了一种由丝胶原复合系统组成的新基质，可提供长期、稳定的培养，并随着时间的推移减少收缩和降解。该矩阵支持包括神经在内的全层皮肤等效物。独特的丝胶原复合系统保留了胶原蛋白的细胞结合域，同时保持皮肤系统的稳定性和力学性能，以便用丝进行长期培养。这种新型复合蛋白质生物材料的实用性通过使用原代细胞（包括神经和免疫细胞）对全层人体皮肤系统进行生物工程来证明，以建立具有神经免疫皮肤系统的 HSE。与体外仅皮肤 HSE 对照相比，具有神经元和皮下组织的 HSE 表现出更高的促炎细胞因子分泌。蛋白质组学分析证实所有样本组中都存在几种与炎症相关的蛋白质，但由于模型的复杂性，具有神经元的 HSE 检测到的蛋白质数量最多。这种改进的体外全厚度 HSE 模型系统利用交联丝胶原作为生物材料，可以减少对动物模型的依赖，并为评估与皮肤病和药物发现相关的慢性反应提供新的体外组织系统。