Department of Biomedical Engineering, University of Rochester, Rochester, NY 14642, USA.
Biotechnol Bioeng. 2013 May;110(5):1476-86. doi: 10.1002/bit.24799. Epub 2012 Dec 27.
A major challenge in cartilage tissue engineering is the need to recreate the native tissue's anisotropic extracellular matrix structure. This anisotropy has important mechanical and biological consequences and could be crucial for integrative repair. Here, we report that hydrodynamic conditions that mimic the motion-induced flow fields in between the articular surfaces in the synovial joint induce the formation of a distinct superficial layer in tissue engineered cartilage hydrogels, with enhanced production of cartilage matrix proteoglycan and Type II collagen. Moreover, the flow stimulation at the surface induces the production of the surface zone protein Proteoglycan 4 (aka PRG4 or lubricin). Analysis of second harmonic generation signature of collagen in this superficial layer reveals a highly aligned fibrillar matrix that resembles the alignment pattern in native tissue's surface zone, suggesting that mimicking synovial fluid flow at the cartilage surface in hydrodynamic bioreactors could be key to creating engineered cartilage with superficial zone features.
在软骨组织工程中，一个主要的挑战是需要重建天然组织的各向异性细胞外基质结构。这种各向异性具有重要的力学和生物学意义，对于整合修复可能至关重要。在这里，我们报告说，模仿滑膜关节中关节表面之间运动诱导流场的流体动力学条件会在组织工程软骨水凝胶中诱导形成一个明显的浅层，从而增强软骨基质蛋白聚糖和 II 型胶原的产生。此外，表面的流动刺激会诱导表面区蛋白蛋白聚糖 4（又名 PRG4 或润滑素）的产生。对该浅层中胶原蛋白的二次谐波产生特征的分析显示出高度有序的纤维状基质，类似于天然组织表面区的排列模式，这表明在流体动力学生物反应器中模仿滑液在软骨表面的流动可能是创建具有表面区特征的工程软骨的关键。
