Hunter Christopher J, Mouw Janna K, Levenston Marc E
Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, USA.
Osteoarthritis Cartilage. 2004 Feb;12(2):117-30. doi: 10.1016/j.joca.2003.08.009.
Various strategies have been tested to direct and control matrix synthesis in tissue engineered cartilage, including mechanical stimulation of the construct both before and after implantation. This study examined the effects of oscillatory compression on chondrocytes in a fibrin-based tissue engineered cartilage.
Chondrocyte-seeded fibrin gels were cultured under unconfined mechanical compression for 10 or 20 days (free-swelling, 10% static, or 10+/-4% at 0.1 or 1Hz). During the culture period, accumulation of nitrite, sGAG, and proteolytic enzymes in the culture media were monitored. Following culture, the mechanical stiffness and biochemical content of the gels (DNA, sGAG, and hydroxyproline content and GAG Delta-disaccharide composition) were assessed.
Compared to free-swelling conditions, static compression had little effect on the mechanical stiffness or biochemical content of the gels. Compared to static compression, oscillatory compression produced softer gels, inhibited sGAG and hydroxyproline accumulation in the gels, and stimulated accumulation of nitrite and sGAG in the culture media. Minimal differences were observed in DNA content and Delta-disaccharide composition across treatment conditions.
In this study, oscillatory compression inhibited formation of cartilage-like tissues by chondrocytes in fibrin gels. These results suggest that the effects of mechanical stimuli on tissue engineered cartilage may vary substantially between different scaffold systems.
已对多种策略进行了测试，以指导和控制组织工程软骨中的基质合成，包括在植入前和植入后对构建体进行机械刺激。本研究考察了振荡压缩对基于纤维蛋白的组织工程软骨中软骨细胞的影响。
将接种有软骨细胞的纤维蛋白凝胶在无约束机械压缩下培养10天或20天（自由膨胀、10%静态或在0.1或1Hz下10±4%）。在培养期间，监测培养基中亚硝酸盐、硫酸化糖胺聚糖（sGAG）和蛋白水解酶的积累。培养后，评估凝胶的机械硬度和生化含量（DNA、sGAG和羟脯氨酸含量以及GAG二糖组成）。
与自由膨胀条件相比，静态压缩对凝胶的机械硬度或生化含量影响很小。与静态压缩相比，振荡压缩产生更软的凝胶，抑制凝胶中sGAG和羟脯氨酸的积累，并刺激培养基中亚硝酸盐和sGAG的积累。在不同处理条件下，DNA含量和二糖组成的差异最小。
在本研究中，振荡压缩抑制了纤维蛋白凝胶中软骨细胞形成类软骨组织。这些结果表明，机械刺激对组织工程软骨的影响在不同的支架系统之间可能有很大差异。
