Continuous gradients present at tissue interfaces such as osteochondral systems, reflect complex tissue functions and involve changes in extracellular matrix compositions, cell types and mechanical properties. New and versatile biomaterial strategies are needed to create suitable biomimetic engineered grafts for interfacial tissue engineering. Silk protein-based composites, coupled with selective peptides with mineralization domains, were utilized to mimic the soft-to-hard transition in osteochondral interfaces. The gradient composites supported tunable mineralization and mechanical properties corresponding to the spatial concentration gradient of the mineralization domains (R5 peptide). The composite system exhibited continuous transitions in terms of composition, structure and mechanical properties, as well as cytocompatibility and biodegradability. The gradient silicified silk/R5 composites promoted and regulated osteogenic differentiation of human mesenchymal stem cells in an osteoinductive environment in vitro. The cells differentiated along the composites in a manner consistent with the R5-gradient profile. This novel biomimetic gradient biomaterial design offers a useful approach to meet a broad range of needs in regenerative medicine.

中文翻译：

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界面组织工程仿生梯度蛋白/生物二氧化硅复合材料的多尺度设计与合成

存在于诸如骨软骨系统的组织界面处的连续梯度反映了复杂的组织功能，并且涉及细胞外基质组成，细胞类型和机械性质的变化。需要新的和通用的生物材料策略来创建适用于界面组织工程的仿生生物工程移植物。基于丝绸蛋白的复合材料，加上具有矿化域的选择性肽，被用来模拟骨软骨界面中的软硬过渡。梯度复合物支持可调节的矿化和力学性能，对应于矿化域（R5肽）的空间浓度梯度。复合系统在成分，结构和机械性能方面表现出连续的转变，以及细胞相容性和生物降解性。梯度硅化丝绸/ R5复合材料在骨诱导环境中促进和调节人间充质干细胞的成骨分化。体外。细胞以与R5梯度​​曲线一致的方式沿着复合物分化。这种新颖的仿生梯度生物材料设计提供了一种有用的方法，可以满足再生医学的广泛需求。