Department of Chemical and Materials Engineering, School of Engineering & Digital Sciences, Nazarbayev University, 53 Kabanbay Batyr, Nur-Sultan 010000, Kazakhstan.
Department of Biological Sciences, Nazarbayev University, 53 Kabanbay Batyr, Nur-Sultan 010000, Kazakhstan.
Molecules. 2021 Feb 24;26(5):1204. doi: 10.3390/molecules26051204.
More than 200,000 people are suffering from Anterior Cruciate Ligament (ACL) related injuries each year in the US. There is an unmet clinical demand for improving biological attachment between grafts and the host tissue in addition to providing mechanical support. For biological graft integration, it is important to provide a physiologically feasible environment for the host cells to enable them to perform their duties. However, behavior of cells during ACL healing and the mechanism of ACL healing is not fully understood partly due to the absence of appropriate environment to test cell behavior both in vitro and in vivo. This study aims at (i) investigating the change in fibril diameter of bovine ACL tissue upon injury and (ii) fabricating nanofiber-based scaffolds to represent the morphology and structure of healthy and injured ACL tissues. We hypothesized that distribution and mean diameter of ACL fibrils will be altered upon injury. Findings revealed that the collagen fibril diameter distribution of bovine ACL changed from bimodal to unimodal upon injury with subsequent decrease in mean diameter. Polycaprolactone (PCL) scaffold fiber diameter distribution exhibited similar bimodal and unimodal distribution behavior to qualitatively represent the cases of healthy and injured ACL, respectively. The native ACL tissue demonstrated comparable modulus values only with the aligned bimodal PCL scaffolds. There was significant difference between mechanical properties of aligned bimodal and unaligned unimodal PCL scaffolds. We believe that the results obtained from measurements of diameter of collagen fibrils of native bovine ACL tissue can serve as a benchmark for scaffold design.
每年在美国，有超过 20 万人患有前交叉韧带（ACL）相关损伤。除了提供机械支撑外，还需要改善移植物和宿主组织之间的生物附着，以满足未满足的临床需求。对于生物移植物的整合，为宿主细胞提供一个生理可行的环境以使其能够发挥作用非常重要。然而，ACL 愈合过程中细胞的行为以及 ACL 愈合的机制尚未完全了解，部分原因是缺乏合适的环境来测试细胞在体外和体内的行为。本研究旨在：（i）研究牛 ACL 组织在受伤时纤维直径的变化；（ii）制备基于纳米纤维的支架，以代表健康和受伤 ACL 组织的形态和结构。我们假设 ACL 纤维的分布和平均直径会在受伤后发生变化。研究结果表明，牛 ACL 的胶原纤维直径分布在受伤后从双峰变为单峰，随后平均直径减小。聚己内酯（PCL）支架纤维直径分布表现出类似的双峰和单峰分布行为，分别定性地代表健康和受伤的 ACL 情况。天然 ACL 组织仅与定向排列的双峰 PCL 支架具有可比的模量值。定向排列的双峰和未定向排列的单峰 PCL 支架的机械性能存在显著差异。我们相信，从天然牛 ACL 组织胶原纤维直径的测量结果可以作为支架设计的基准。
