Sah R L, Trippel S B, Grodzinsky A J
Department of Bioengineering, University of California at San Diego, La Jolla, California 92093-1412, USA.
J Orthop Res. 1996 Jan;14(1):44-52. doi: 10.1002/jor.1100140109.
The effects of fetal bovine serum, insulin-like growth factor-I, and fibroblast growth factor-2 on the regulation of the functional physical properties of adult bovine cartilage explants during an incubation period of 18-20 days was determined, and the relationship between the measured functional properties of the cartilage and the tissue composition was assessed. Cartilage disks were tested in the uniaxial radially confined configuration by the application of low amplitude oscillatory displacement and measurement of the resultant load and streaming potential. For the control cartilage terminated just after explant, the modulus was 0.39 +/- 0.28 MPa, the open circuit hydraulic permeability was 2.0 +/- 1.0 x 10(-15) m2/(Pa.sec), and the electrokinetic (streaming potential) coefficient was -2.3 +/- 0.6 mV/MPa. Incubation of cartilage in medium supplemented with serum or insulin-like growth factor-I resulted in maintenance of the modulus and electrokinetic coefficient, whereas incubation in basal medium or medium supplemented with fibroblast growth factor-2 led to a marked decrease from control values in the modulus and the amplitude of the electrokinetic coefficient. All of the culture conditions examined resulted in an increase in permeability that was not statistically significant. The variation in the electromechanical properties of all the cartilage samples tested was related to the density of tissue proteoglycan and collagen (hydroxyproline). The modulus was correlated with both the density of tissue proteoglycan (+0.014 MPa/[mg/ml]) and the density of tissue hydroxyproline (+0.008 MPa/[mg/ml]). The electrokinetic coefficient was also correlated with the density of proteoglycan (-0.080 [mV/MPa]/[mg/ml]) and the density of hydroxyproline (+0.064 [mV/MPa]/[mg/ml]). These data indicate that the regulation of chondrocyte matrix metabolism by growth factors can significantly affect the physical properties and function of cartilage.
测定了胎牛血清、胰岛素样生长因子-I和成纤维细胞生长因子-2在18 - 20天孵育期对成年牛软骨外植体功能物理特性调节的影响，并评估了所测软骨功能特性与组织组成之间的关系。通过施加低振幅振荡位移并测量产生的负荷和流动电位，以单轴径向受限构型对软骨盘进行测试。对于刚取出外植体后即终止的对照软骨，其模量为0.39±0.28兆帕，开路水力渗透率为2.0±1.0×10⁻¹⁵平方米/(帕·秒)，电动（流动电位）系数为 -2.3±0.6毫伏/兆帕。在补充血清或胰岛素样生长因子-I的培养基中孵育软骨可使模量和电动系数维持不变，而在基础培养基或补充成纤维细胞生长因子-2的培养基中孵育则导致模量和电动系数振幅相对于对照值显著降低。所检测的所有培养条件均导致渗透率增加，但无统计学意义。所测试的所有软骨样品的机电特性变化与组织蛋白聚糖和胶原蛋白（羟脯氨酸）的密度有关。模量与组织蛋白聚糖密度（+0.014兆帕/[毫克/毫升]）和组织羟脯氨酸密度（+0.008兆帕/[毫克/毫升]）均相关。电动系数也与蛋白聚糖密度（-0.080 [毫伏/兆帕]/[毫克/毫升]）和羟脯氨酸密度（+0.064 [毫伏/兆帕]/[毫克/毫升]）相关。这些数据表明生长因子对软骨细胞基质代谢的调节可显著影响软骨的物理特性和功能。
