Department Chemical and Biomolecular Engineering, Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign , Urbana , IL , USA.
Connect Tissue Res. 2019 Nov;60(6):530-543. doi: 10.1080/03008207.2019.1601183. Epub 2019 Apr 22.
Orthopedic injuries often occur at the interface between soft tissues and bone. The tendon-bone junction (TBJ) is a classic example of such an interface. Current clinical strategies for TBJ injuries prioritize mechanical reattachment over regeneration of the native interface, resulting in poor outcomes. The need to promote regenerative healing of spatially-graded tissues inspires our effort to develop new tissue engineering technologies that replicate features of the spatially-graded extracellular matrix and strain profiles across the native TBJ. We recently described a biphasic collagen-glycosaminoglycan (CG) scaffold containing distinct compartment with divergent mineral content and structural alignment (isotropic vs. anisotropic) linked by a continuous interface zone to mimic structural and compositional features of the native TBJ. Here, we report application of cyclic tensile strain (CTS) to the scaffold via a bioreactor leads to non-uniform strain profiles across the spatially-graded scaffold. Further, combinations of CTS and matrix structural features promote rapid, spatially-distinct differentiation profiles of human bone marrow-derived mesenchymal stem cells (MSCs) down multiple osteotendinous lineages. CTS preferentially upregulates MSC activity and tenogenic differentiation in the anisotropic region of the scaffold. This work demonstrates a tissue engineering approach that couples instructive biomaterials with cyclic tensile stimuli to promote regenerative healing of orthopedic interfaces.
骨科损伤常发生在软组织和骨骼的交界处。肌腱-骨结合部(TBJ)就是这种界面的一个典型例子。目前,TBJ 损伤的临床治疗策略侧重于机械修复,而不是原生界面的再生,导致治疗效果不佳。为了促进空间分级组织的再生愈合,我们努力开发新的组织工程技术,以复制原生 TBJ 中空间分级细胞外基质和应变分布的特征。 我们最近描述了一种双相胶原-糖胺聚糖(CG)支架,其中包含具有不同矿物质含量和结构排列(各向同性与各向异性)的不同隔室,通过连续的界面区连接,以模拟原生 TBJ 的结构和组成特征。 在这里,我们报告了通过生物反应器对支架施加循环拉伸应变(CTS)会导致空间分级支架上的非均匀应变分布。此外,CTS 和基质结构特征的组合促进了人骨髓间充质干细胞(MSCs)沿着多个腱骨谱系的快速、空间上有区别的分化。CTS 优先上调支架各向异性区域 MSC 的活性和腱细胞分化。这项工作展示了一种组织工程方法,该方法将有指导意义的生物材料与循环拉伸刺激相结合,以促进骨科界面的再生愈合。