Faculty of Biomedical Engineering, Technion - Israel Institute of Technology, Haifa, Israel.
Biomaterials. 2010 Sep;31(25):6411-6. doi: 10.1016/j.biomaterials.2010.04.052.
Injured peripheral nerve tissue could benefit from biomaterial nerve guidance conduits (NGCs) that are designed to promote neuronal regeneration. Nerve regeneration is a complex multi-step process that involves the remodeling of the ECM surrounding the regenerating neural tissue. Hydrogel biomaterials have been used as provisional matrices to regulate this regeneration process by providing the desired physical properties and controllable degradation characteristics. The purpose of this investigation was to understand the mechanism by which nerve cells penetrate into a hydrogel made from PEGylated fibrinogen. In this context, the dorsal root ganglion (DRG) assay was used as an in vitro model to study the cellular invasion behavior of both neural and nonneuronal cells. Our hypothesis stipulated that DRG cells employ matrix metalloproteinases (MMPs) in order to degrade the dense hydrogel matrix and penetrate the biomaterial. Three dimensional (3D) DRG-hydrogel constructs were cultured with MMP inhibitors (MMPi) and the effect of the inhibitors on DRG cell outgrowth was investigated. We also examined the effect of inhibitors on two dimensional (2D) DRG cell outgrowth on PEGylated fibrinogen hydrogels and on tissue culture polystyrene (TCP). Our results demonstrate that DRG cell outgrowth into and onto PEGylated fibrinogen hydrogels was inhibited by MMPi and that the outgrowth characteristics was dependent on the type of inhibitor and its concentration. MMP-3i and MMP-8i decreased both neuronal and nonneuronal outgrowth, where MMP-3i had a stronger inhibitory effect on nonneuronal cells. MMP-2/9i, on the other hand, affected the neuronal outgrowth much more than the others. We concluded that MMPs play a central role in the process of DRG cell penetration into PEGylated fibrinogen hydrogels and may also regulate the adhesion, migration and elongation of neuronal cells on the surface of these hydrogel biomaterials.
受伤的周围神经组织可以从设计用于促进神经元再生的生物材料神经引导导管（NGC）中受益。神经再生是一个复杂的多步骤过程，涉及到再生神经组织周围细胞外基质（ECM）的重塑。水凝胶生物材料已被用作临时基质，通过提供所需的物理特性和可控的降解特性来调节这种再生过程。本研究的目的是了解神经细胞穿透聚乙二醇化纤维蛋白原水凝胶的机制。在这种情况下，背根神经节（DRG）测定被用作体外模型，以研究神经和非神经细胞的细胞入侵行为。我们的假设规定，DRG 细胞利用基质金属蛋白酶（MMPs）来降解致密的水凝胶基质并穿透生物材料。三维（3D）DRG-水凝胶构建体与 MMP 抑制剂（MMPi）一起培养，并研究抑制剂对 DRG 细胞外生的影响。我们还研究了抑制剂对二维（2D）DRG 细胞在聚乙二醇化纤维蛋白原水凝胶和组织培养聚苯乙烯（TCP）上的外生的影响。我们的结果表明，DRG 细胞向聚乙二醇化纤维蛋白原水凝胶中的生长受到 MMPi 的抑制，并且生长特征取决于抑制剂的类型及其浓度。MMP-3i 和 MMP-8i 降低了神经元和非神经元的生长，其中 MMP-3i 对非神经元细胞的抑制作用更强。另一方面，MMP-2/9i 对神经元的生长影响比其他抑制剂更大。我们得出结论，MMP 在 DRG 细胞穿透聚乙二醇化纤维蛋白原水凝胶的过程中起核心作用，并且还可能调节这些水凝胶生物材料表面上神经元细胞的粘附、迁移和伸长。
