Department of Chemical and Biological Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA; Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA.
Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA.
Biomaterials. 2017 Nov;145:44-55. doi: 10.1016/j.biomaterials.2017.08.025. Epub 2017 Aug 15.
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.
组织界面（如骨软骨系统）存在连续梯度，反映了复杂的组织功能，并涉及细胞外基质组成、细胞类型和机械性能的变化。需要新的多功能生物材料策略来创建适合界面组织工程的仿生工程移植物。基于丝蛋白的复合材料与具有矿化结构域的选择性肽结合，用于模拟骨软骨界面的软-硬过渡。梯度复合材料支持可调的矿化和机械性能，与矿化结构域（R5 肽）的空间浓度梯度相对应。该复合材料系统在组成、结构和机械性能以及细胞相容性和可生物降解性方面表现出连续的转变。梯度硅化丝/R5 复合材料在体外诱导成骨环境中促进和调节人骨髓间充质干细胞的成骨分化。细胞沿着复合材料以与 R5 梯度轮廓一致的方式分化。这种新型仿生梯度生物材料设计为满足再生医学的广泛需求提供了一种有用的方法。
