Dept. Chemical and Biomolecular Engineering, University of Illinois Urbana-Champaign, 110 Roger Adams Laboratory, 600 S. Mathews Ave., Urbana, IL 61801, USA.
Department of Orthopaedic Surgery, University of Michigan Ann Arbor, Ann Arbor, Michigan 48109, USA.
Biomater Sci. 2024 Sep 10;12(18):4806-4822. doi: 10.1039/d4bm00543k.
Rotator cuff injuries present a clinical challenge for repair due to current limitations in functional regeneration of the native tendon-to-bone enthesis. A biomaterial that can regionally instruct unique tissue-specific phenotypes offers potential to promote enthesis repair. We have recently demonstrated the mechanical benefits of a stratified triphasic biomaterial made up of tendon- and bone-mimetic collagen scaffold compartments connected a continuous hydrogel, and we now explore the potential of a biologically favorable enthesis hydrogel for this application. Here we report behavior of human mesenchymal stem cells (hMSCs) within thiolated gelatin (Gel-SH) hydrogels in response to chondrogenic stimuli as well as paracrine signals derived from MSC-seeded bone and tendon scaffold compartments. Chondrogenic differentiation media promoted upregulation of cartilage and entheseal fibrocartilage matrix markers , , and as well as the enthesis-associated transcription factors , , and in hMSCs within Gel-SH. Similar effects were observed in response to TGF-β3 and BMP-4, enthesis-associated growth factors known to play a role in entheseal development and maintenance. Conditioned media generated by hMSCs seeded in tendon- and bone-mimetic collagen scaffolds influenced patterns of gene expression regarding enthesis-relevant growth factors, matrix markers, and tendon-to-bone transcription factors for hMSCs within the material. Together, these findings demonstrate that a Gel-SH hydrogel provides a permissive environment for enthesis tissue engineering and highlights the significance of cellular crosstalk between adjacent compartments within a spatially graded biomaterial.
肩袖损伤的修复具有临床挑战性，这是由于目前在天然肌腱-骨结合处的功能再生方面存在局限性。一种能够在局部指导独特组织特异性表型的生物材料为促进结合处修复提供了潜力。我们最近证明了由肌腱和骨模拟胶原支架隔室组成的分层三相生物材料的机械优势，这些隔室通过连续水凝胶连接，现在我们探索了这种具有生物优势的结合处水凝胶在这一应用中的潜力。在这里，我们报告了硫醇化明胶（Gel-SH）水凝胶中人类间充质干细胞（hMSCs）对软骨形成刺激以及源自 MSC 接种的骨和肌腱支架隔室的旁分泌信号的反应行为。软骨形成分化培养基促进了软骨和结合处纤维软骨基质标志物、和在 Gel-SH 中的 hMSCs 中的上调，以及结合处相关转录因子、和。在响应 TGF-β3 和 BMP-4 时也观察到了类似的效果，这些生长因子是已知在结合处发育和维持中起作用的结合处相关生长因子。在肌腱和骨模拟胶原支架中接种的 hMSCs 产生的条件培养基影响了 hMSCs 中与结合处相关的生长因子、基质标志物和肌腱-骨转录因子的基因表达模式。总之，这些发现表明 Gel-SH 水凝胶为结合处组织工程提供了一个许可的环境，并强调了在空间分级生物材料中相邻隔室之间细胞串扰的重要性。
