Institute of Medical and Biological Engineering (iMBE), Faculty of Biomedical Sciences, University of Leeds, Leeds, UK.
Institute of Medical and Biological Engineering (iMBE), Faculty of Biomedical Sciences, University of Leeds, Leeds, UK.
J Mech Behav Biomed Mater. 2019 Mar;91:18-23. doi: 10.1016/j.jmbbm.2018.11.023. Epub 2018 Nov 26.
Development of new replacement grafts for anterior cruciate ligament (ACL) repair requires mechanical testing to ensure they can provide joint stability following implantation. A decellularised porcine superflexor tendon (pSFT) has been developed previously as an alternative to current reconstruction methods and subjected to biomechanical analysis. The application of varied strain rates to biological tissues is known to alter their biomechanical properties, however the effects of decellularisation on strain rate dependent and dynamic mechanical behaviour of tissues have not been explored. This study utilised tensile testing to investigate the material properties of native and decellularised pSFTs at three different strain rates (1%.s, 10%.s and 100%.s). In addition, dynamic mechanical analysis (DMA) was used to ascertain the relative contributions of the solid and fluid phase components of the tissues. Ultimate tensile strength was significantly reduced in decellularised compared with native untreated pSFTs but was unaffected by strain rate. In contrast, toe region moduli increased with increasing strain rate for native tissues, but this effect was not observed in decellularised pSFTs. Linear region moduli were unaffected by strain rate, but were significantly reduced in decellularised pSFT compared with native tissue. Following DMA, significant reductions in dynamic modulus, storage modulus and loss modulus were seen in decellularised compared with native pSFT. Interestingly, the damping ability of the tendons was unaffected by decellularisation, suggesting that solid and fluid phases of the tissue were affected equally. These results, alongside previous studies, suggest that decellularisation affects collagen crimp, tissue swelling and collagen fibre sliding. However, despite these findings, the biomechanical properties of decellularised pSFT remain sufficient to act as an off-the-shelf solution for ACL reconstruction.
为了确保前交叉韧带 (ACL) 修复后的新替代移植物具有关节稳定性，需要进行机械测试。先前已经开发出脱细胞猪超屈肌腱 (pSFT) 作为当前重建方法的替代品，并进行了生物力学分析。众所周知，向生物组织施加不同的应变速率会改变其生物力学特性，但是脱细胞化对组织的应变速率相关和动态力学行为的影响尚未得到探索。本研究利用拉伸测试在三种不同的应变速率（1%。s、10%。s 和 100%。s）下研究了天然和脱细胞化 pSFT 的材料特性。此外，动态力学分析 (DMA) 用于确定组织的固相和液相成分的相对贡献。与天然未处理的 pSFT 相比，脱细胞化的 pSFT 的极限拉伸强度显着降低，但不受应变速率的影响。相比之下，对于天然组织，趾区模量随应变速率的增加而增加，但在脱细胞化的 pSFT 中未观察到这种效应。线性区模量不受应变速率的影响，但在脱细胞化的 pSFT 中与天然组织相比显着降低。DMA 后，与天然 pSFT 相比，脱细胞化的 pSFT 的动态模量、储能模量和损耗模量显着降低。有趣的是，肌腱的阻尼能力不受脱细胞化的影响，这表明组织的固相和液相受到同等影响。这些结果与之前的研究一起表明，脱细胞化会影响胶原卷曲、组织肿胀和胶原纤维滑动。然而，尽管有这些发现，脱细胞化的 pSFT 的生物力学性能仍然足以作为 ACL 重建的即用型解决方案。
