Tissue Engineering Lab, Department of Anatomical Sciences, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
Histomorphometry and stereology research Center, Shiraz Medical School, Shiraz University of Medical Sciences, Shiraz, Iran.
Stem Cell Res Ther. 2022 Jul 30;13(1):382. doi: 10.1186/s13287-022-03058-w.
Tissue engineering focuses on reconstructing the damaged meniscus by mimicking the native meniscus. The application of mechanical loading on chondrocyte-laden decellularized whole meniscus is providing the natural microenvironment. The goal of this study was to evaluate the effects of dynamic compression and shear load on chondrocyte-laden decellularized meniscus.
The fresh samples of rabbit menisci were decellularized, and the DNA removal was confirmed by histological assessments and DNA quantification. The biocompatibility, degradation and hydration rate of decellularized menisci were evaluated. The decellularized meniscus was injected at a density of 1 × 10 chondrocyte per scaffold and was subjected to 3 cycles of dynamic compression and shear stimuli (1 h of 5% strain, ± 25°shear at 1 Hz followed by 1 h rest) every other day for 2 weeks using an ad hoc bioreactor. Cytotoxicity, GAG content, ultrastructure, gene expression and mechanical properties were examined in dynamic and static condition and compared to decellularized and intact menisci.
Mechanical stimulation supported cell viability and increased glycosaminoglycan (GAG) accumulation. The expression of collagen-I (COL-I, 10.7-folds), COL-II (6.4-folds), aggrecan (AGG, 3.2-folds), and matrix metalloproteinase (MMP3, 2.3-folds) was upregulated compared to the static conditions. Furthermore, more aligned fibers and enhanced tensile strength were observed in the meniscus treated in dynamic condition with no sign of mineralization.
Compress and shear stimulation mimics the loads on the joint during walking and be able to improve cell function and ultrastructure of engineered tissue to recreate a functional artificial meniscus.
组织工程专注于通过模拟天然半月板来重建受损的半月板。对负载软骨细胞的去细胞化全半月板施加机械负荷为软骨细胞提供了天然的微环境。本研究旨在评估动态压缩和剪切负荷对负载软骨细胞的去细胞化半月板的影响。
新鲜兔半月板去细胞化，通过组织学评估和 DNA 定量确认 DNA 去除。评估去细胞半月板的生物相容性、降解和水合速率。将去细胞半月板以 1×10 个软骨细胞/支架的密度注入，并使用专门的生物反应器每隔一天进行 3 个周期的动态压缩和剪切刺激（1 小时 5%应变，±25°剪切，1 Hz，随后 1 小时休息），持续 2 周。在动态和静态条件下检查细胞毒性、糖胺聚糖 (GAG) 含量、超微结构、基因表达和力学性能，并与去细胞化和完整半月板进行比较。
机械刺激支持细胞活力并增加糖胺聚糖 (GAG) 积累。与静态条件相比，COL-I（10.7 倍）、COL-II（6.4 倍）、聚集蛋白聚糖 (AGG，3.2 倍) 和基质金属蛋白酶 (MMP3，2.3 倍) 的表达上调。此外，在动态条件下处理的半月板中观察到纤维更对齐且拉伸强度增强，且没有矿化迹象。
压缩和剪切刺激模拟了行走过程中关节的负荷，能够改善细胞功能和工程组织的超微结构，以重建功能性人工半月板。
