Rundell S A, Haut R C
Orthopaedic Biomechanics Laboratories, College of Osteopathic Medicine, Michigan State University, A407 East Fee Hall, East Lansing, 48824, USA.
J Biomech. 2006;39(10):1933-8. doi: 10.1016/j.jbiomech.2005.05.035. Epub 2005 Jul 27.
Previous studies on chondral explants have not clearly described to what extent the degree and the distribution of cell death are dependent on the amount of free swelling seen during tissue equilibration in a standard culture medium. The current study hypothesized that increased fluid content inside equilibrated chondral explants, when subjected to injurious compression, would lead to greater matrix damage during unconfined compression. Equilibrated and non-equilibrated chondral explants were loaded to 30 MPa at a fast rate of loading ( approximately 600 MPa/s). Stress-strain curves were documented for each explant. Matrix damage was assessed by the length of surface fissures. Chondrocyte viability was also measured in the various layers of the explants. The stiffness of the equilibrated specimens was less than non-equilibrated specimens, and it correlated with the amount of fluid absorbed during equilibration. More matrix damage and associated cell death in the superficial zone were documented in equilibrated than non-equilibrated explants, and these correlated positively with fluid absorbed during equilibration. This study indicated that equilibration of chondral explants in a standard culture medium alters their response to mechanical loading in terms of stiffness, matrix damage and cell viability.
先前关于软骨外植体的研究尚未明确描述细胞死亡的程度和分布在多大程度上取决于在标准培养基中组织平衡期间所观察到的自由肿胀量。当前的研究假设，当受到损伤性压缩时，平衡后的软骨外植体内增加的液体含量会在无侧限压缩过程中导致更大的基质损伤。将平衡后的和未平衡的软骨外植体以快速加载速率（约600MPa/s）加载至30MPa。记录每个外植体的应力-应变曲线。通过表面裂缝的长度评估基质损伤。还测量了外植体各层中的软骨细胞活力。平衡后的标本刚度低于未平衡的标本，且其与平衡期间吸收的液体量相关。与未平衡的外植体相比，平衡后的外植体在表层记录到更多的基质损伤和相关的细胞死亡，且这些与平衡期间吸收的液体呈正相关。本研究表明，在标准培养基中对软骨外植体进行平衡处理会在刚度、基质损伤和细胞活力方面改变其对机械加载的反应。
