Mary & Dick Holland Regenerative Medicine Program, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States.
Division of Cardiology, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States.
ACS Appl Mater Interfaces. 2022 Feb 23;14(7):8693-8704. doi: 10.1021/acsami.1c20320. Epub 2022 Feb 11.
Decellularized nerve hydrogels (dNHs) containing bioactive molecules are promising biomaterials for peripheral nerve injury (PNI) treatment and have been extensively applied in clinical and preclinical practice. However, most previous research projects studied their influences on nerve-related cellular behaviors in two dimensions (2D) without taking hydrogel biomechanics into consideration. The molecular mechanisms underlying the beneficial microenvironment provided by dNHs also remain unclear. In this study, dNHs from rat sciatic nerves were prepared, and their effects on Schwann cell (SC) and dorsal root ganglion (DRG) neurite behaviors were evaluated and compared to commercial rat tail type I collagen (Col) hydrogels in three-dimensional (3D) environments. We found that dNHs could promote SC proliferation and neurite outgrowth, and both the hydrogel mechanics and components contributed to the dNH functionalization. Through proteomics analysis, we found that laminin (LAM) and type V collagen (COLV) exclusively and abundantly existed in dNHs. By adding exogenous LAM and COLV into Col hydrogels, we demonstrated that they regulated SC gene expression and that LAM could promote SC spreading and neurite outgrowth, while COLV improved SC proliferation. Lastly, dNHs were fabricated into paper-like, aligned nerve scaffolds through unidirectional freezing to expand the dNH applications in PNI treatment.
脱细胞神经水凝胶（dNHs）含有生物活性分子，是治疗周围神经损伤（PNI）的有前途的生物材料，已广泛应用于临床和临床前实践。然而，大多数先前的研究项目研究了它们在不考虑水凝胶生物力学的情况下对神经相关细胞行为的二维（2D）影响。dNHs 提供的有益微环境的分子机制也仍不清楚。在这项研究中，从大鼠坐骨神经中制备了 dNHs，并在三维（3D）环境中评估并比较了它们对雪旺细胞（SC）和背根神经节（DRG）轴突行为的影响与商业大鼠尾型 I 型胶原蛋白（Col）水凝胶。我们发现 dNHs 可以促进 SC 的增殖和轴突生长，并且水凝胶的力学性能和组成都有助于 dNH 的功能化。通过蛋白质组学分析，我们发现层粘连蛋白（LAM）和 V 型胶原（COLV）仅在 dNHs 中大量存在。通过将外源性 LAM 和 COLV 添加到 Col 水凝胶中，我们证明它们调节了 SC 的基因表达，并且 LAM 可以促进 SC 的铺展和轴突生长，而 COLV 则提高了 SC 的增殖。最后，通过单向冻结将 dNHs 制成纸状、排列的神经支架，以扩展 dNHs 在 PNI 治疗中的应用。
