Scialla Stefania, Gullotta Fabiana, Izzo Daniela, Palazzo Barbara, Scalera Francesca, Martin Ivan, Sannino Alessandro, Gervaso Francesca
Department of Engineering for Innovation, University of Salento, Lecce, Italy.
Institute of Polymers, Composites and Biomaterials - National Research Council, Naples, Italy.
J Biomed Mater Res A. 2022 Jul;110(7):1372-1385. doi: 10.1002/jbm.a.37379. Epub 2022 Mar 9.
Articular cartilage degeneration is still an unsolved issue owing to its weak repairing capabilities, which usually result in fibrocartilage tissue formation. This fibrous tissue lacks of structural and bio-mechanical properties, degrading over time. Currently, arthroscopic techniques and autologous transplantation are the most used clinical procedures. However, rather than restoring cartilage integrity, these methods only postpone further cartilage deterioration. Therefore, tissue engineering strategies aimed at selecting scaffolds that remarkably support the chondrogenic differentiation of human mesenchymal stem cells (hMSCs) could represent a promising solution, but they are still challenging for researchers. In this study, the influence of two different genipin (Gp) crosslinking routes on collagen (Coll)-based scaffolds in terms of hMSCs chondrogenic differentiation and biomechanical performances was investigated. Three-dimensional (3D) porous Coll scaffolds were fabricated by freeze-drying techniques and were crosslinked with Gp following a "two-step" and an in "bulk" procedure, in order to increase the physico-mechanical stability of the structure. Chondrogenic differentiation efficacy of hMSCs and biomechanical behavior under compression forces through unconfined stress-strain tests were assessed. Coll/Gp scaffolds revealed an isotropic and highly homogeneous pore distribution along with an increase in the stiffness, also supported by the increase in the Coll denaturation temperature (T = 57-63°C) and a significant amount of Coll and GAG deposition during the 3 weeks of chondrogenic culture. In particular, the presence of Gp in "bulk" led to a more uniform and homogenous chondral-like matrix deposition by hMSCs if compared to the results obtained from the Gp "two-step" functionalization procedure.
由于关节软骨修复能力较弱，通常会导致纤维软骨组织形成，因此关节软骨退变仍是一个尚未解决的问题。这种纤维组织缺乏结构和生物力学特性，会随着时间推移而退化。目前，关节镜技术和自体移植是最常用的临床治疗方法。然而，这些方法并非恢复软骨完整性，而只是延缓了软骨的进一步退变。因此，旨在选择能显著支持人间充质干细胞（hMSCs）软骨分化的支架的组织工程策略可能是一个有前景的解决方案，但对研究人员来说仍具有挑战性。在本研究中，研究了两种不同的京尼平（Gp）交联途径对基于胶原蛋白（Coll）的支架在hMSCs软骨分化和生物力学性能方面的影响。通过冷冻干燥技术制备了三维（3D）多孔Coll支架，并按照“两步法”和“整体法”用Gp进行交联，以提高结构的物理机械稳定性。通过无侧限应力应变试验评估了hMSCs的软骨分化效果和压缩力作用下的生物力学行为。Coll/Gp支架显示出各向同性且高度均匀的孔分布，同时硬度增加，Coll变性温度（T = 57 - 63°C）的升高以及软骨形成培养3周期间大量的Coll和GAG沉积也支持了这一点。特别是，与Gp“两步法”功能化程序的结果相比，“整体法”中Gp的存在导致hMSCs形成更均匀且类似软骨的基质沉积。
