Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana, USA.
Department of Orthopaedic Surgery, Washington University, St. Louis, Missouri, USA.
J Biomed Mater Res A. 2023 Dec;111(12):1875-1887. doi: 10.1002/jbm.a.37588. Epub 2023 Jul 25.
Tendon tears are common and healing often occurs incompletely and by fibrosis. Tissue engineering seeks to improve repair, and one approach under investigation uses cell-seeded scaffolds containing biomimetic factors. Retention of biomimetic factors on the scaffolds is likely critical to maximize their benefit, while minimizing the risk of adverse effects, and without losing the beneficial effects of the biomimetic factors. The aim of the current study was to evaluate cross-linking methods to enhance the retention of tendon-derived matrix (TDM) on electrospun poly(ε-caprolactone) (PCL) scaffolds. We tested the effects of ultraviolet (UV) or carbodiimide (EDC:NHS:COOH) crosslinking methods to better retain TDM to the scaffolds and stimulate tendon-like matrix synthesis. Initially, we tested various crosslinking configurations of carbodiimide (2.5:1:1, 5:2:1, and 10:4:1 EDC:NHS:COOH ratios) and UV (30 s 1 J/cm , 60 s 1 J/cm , and 60 s 4 J/cm ) on PCL films compared to un-crosslinked TDM. We found that no crosslinking tested retained more TDM than coating alone (Kruskal-Wallis: p > .05), but that human adipose stem cells (hASCs) spread most on the 60 s 1 J/cm UV- and 2.5:1:1 EDC-crosslinked films (Kruskal-Wallis: p < .05). Next, we compared the effects of 60 s 1 J/cm UV- and 2.5:1:1 EDC-crosslinked to TDM-coated and untreated PCL scaffolds on hASC-induced tendon-like differentiation. UV-crosslinked scaffolds had greater modulus and stiffness than PCL or TDM scaffolds, and hASCs spread more on UV-crosslinked scaffolds (ANOVA: p < .05). Fourier transform infrared spectra revealed that UV- or EDC-crosslinking TDM did not affect the peaks at wavenumbers characteristic of tendon. Crosslinking TDM to electrospun scaffolds improves tendon-like matrix synthesis, providing a viable strategy for improving retention of TDM on electrospun PCL scaffolds.
肌腱撕裂很常见,而且愈合通常不完全,会形成纤维化。组织工程旨在改善修复效果,一种正在研究的方法是使用含有仿生因子的细胞接种支架。保留支架上的仿生因子对于最大限度地发挥其益处、最大限度地降低不良反应风险以及保持仿生因子的有益效果可能至关重要。本研究旨在评估交联方法,以增强肌腱衍生基质(TDM)在静电纺聚己内酯(PCL)支架上的保留。我们测试了紫外线(UV)或碳二亚胺(EDC:NHS:COOH)交联方法的效果,以更好地将 TDM 保留在支架上并刺激肌腱样基质合成。最初,我们测试了不同的碳二亚胺交联(2.5:1:1、5:2:1 和 10:4:1 EDC:NHS:COOH 比)和 UV(30 秒 1J/cm 、60 秒 1J/cm 和 60 秒 4J/cm )交联配置对 PCL 薄膜的影响,与未经交联的 TDM 进行比较。我们发现,没有任何交联方法比单独涂层保留更多的 TDM(Kruskal-Wallis:p>.05),但人脂肪干细胞(hASC)在 60 秒 1J/cm UV 和 2.5:1:1 EDC 交联膜上的铺展效果最好(Kruskal-Wallis:p<.05)。接下来,我们比较了 60 秒 1J/cm UV 和 2.5:1:1 EDC 交联的 TDM 涂层和未处理的 PCL 支架对 hASC 诱导的肌腱样分化的影响。UV 交联支架的模量和刚度大于 PCL 或 TDM 支架,hASC 在 UV 交联支架上的铺展效果更好(ANOVA:p<.05)。傅里叶变换红外光谱表明,UV 或 EDC 交联 TDM 不会影响特征峰的峰数肌腱。将 TDM 交联到静电纺丝支架上可改善肌腱样基质的合成,为提高静电纺丝 PCL 支架上 TDM 的保留提供了可行的策略。