关节软骨微元流动电势的数值分析

Numerical Analysis on Micro-Element Streaming Potential of Articular Cartilage

目的了解由间质液流动而产生的流动电势在关节软骨中的分布规律,获得一定的软骨电特性。方法将流体控制方程与静电理论结合,建立软骨二维微元模型,通过有限元法计算在一定压力下微元内产生的稳态流动电势。结果在长度为5μm处关节软骨微孔隙模型中的流动电势约为38.4μV,外压和Zeta电势对软骨模型的流动电势影响比较大,并且呈线性增长的关系。流动电势随离子数浓度的增加而减小,但浓度对软骨流动电势影响有所不同。当离子数浓度较低时,流动电势对离子数浓度依赖较大;当离子数浓度较高时,离子数浓度对流动电势的影响很小。结论研究结果为利用电流、电场、电磁场刺激等方法对软骨细胞的分化增殖、关节软骨疾病防治和治疗、组织工程化软骨研制以及关节软骨损伤修复提供重要的理论依据。

Objective To investigate the distribution of streaming potential generated by interstitial fluid flow in articular cartilage and obtain electrical characteristics of articular cartilage.Methods The governing equation of fluid and electrostatic theory were combined to establish a two-dimensional(2D)micro-element model of cartilage,and the steady streaming potential generated in microelement under certain pressure was calculated by finite element method.Results The streaming potential in micro-pore model of articular cartilage with the length of 5μm was about 38.4μV.The effect of external pressure and Zeta potential on streaming potential of articular cartilage model was significant and showed a linear increase relationship.The streaming potential decreased with the increase of ion number concentration,but the concentration had different effects on streaming potential of articular cartilage.When the ion number concentration was low,streaming potential was more dependent on ion number concentration.When ion number concentration was high,the effect of ion number concentration on streaming potential was very small.Conclusions The results of this study provide important theoretical basis for differentiation and proliferation of chondrocytes,prevention and treatment of articular cartilage diseases,development of tissue-engineered cartilage and repair of articular cartilage injury by means of electric current,electric field and electromagnetic field stimulation.