Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA.
Proc Natl Acad Sci U S A. 2012 May 15;109(20):7699-704. doi: 10.1073/pnas.1119474109. Epub 2012 May 2.
Biomaterials for bone tissue regeneration represent a major focus of orthopedic research. However, only a handful of polymeric biomaterials are utilized today because of their failure to address critical issues like compressive strength for load-bearing bone grafts. In this study development of a high compressive strength (~13 MPa hydrated state) polymeric bone composite materials is reported, based on silk protein-protein interfacial bonding. Micron-sized silk fibers (10-600 µm) obtained utilizing alkali hydrolysis were used as reinforcement in a compact fiber composite with tunable compressive strength, surface roughness, and porosity based on the fiber length included. A combination of surface roughness, porosity, and scaffold stiffness favored human bone marrow-derived mesenchymal stem cell differentiation toward bone-like tissue in vitro based on biochemical and gene expression for bone markers. Further, minimal in vivo immunomodulatory responses suggested compatibility of the fabricated silk-fiber-reinforced composite matrices for bone engineering applications.
用于骨组织再生的生物材料是矫形外科研究的主要重点。然而，由于它们未能解决关键问题，例如用于承重骨移植物的抗压强度，目前仅使用少数几种聚合生物材料。在这项研究中，基于丝蛋白-蛋白界面键合，开发了一种具有高抗压强度（~13 MPa 水合状态）的聚合骨复合材料。利用碱水解获得的微米级丝纤维（10-600 µm）被用作增强材料，用于具有可调抗压强度、表面粗糙度和孔隙率的致密纤维复合材料中，基于包含的纤维长度。表面粗糙度、孔隙率和支架刚度的组合有利于人骨髓间充质干细胞在体外向骨样组织分化，基于骨标志物的生化和基因表达。此外，体内免疫调节反应最小化表明所制造的丝纤维增强复合材料基质适用于骨工程应用。
