Background and objective In avascular or hypovascular tissues, elements required for maintaining tissue functions are recruited through diffusion, which is highly related with the permeability of the extracellular matrix in health and injury. Here, we investigate the effect of collagen fibril diameter distribution of bovine Anterior Cruciate Ligament (ACL) tissue on the hydraulic permeability of the matrix. Based on the fact that the diameter distribution is significantly different between healthy and injured ACL tissues, our study aims to investigate the effect of such variability on the hydraulic permeability. Methods Simulations are carried out in 3D geometries reconstructed from actual collagen filament/fibril diameter distributions obtained from healthy and injured tissue samples (n=3). The fluid flow through the fibrous tissue is modeled based on Eringen's theory of micropolar fluid flow to determine the effects of vortex viscosity (m) and spin gradient viscosity (N) on hydraulic permeability. Results Computational results indicate that the hydraulic permeability of models which are replicates of healthy ACL tissues is higher than that of the injured, indicating that the filament size distribution might play an important role on fluid and nutrient transport through ligament tissues. Conclusions These findings underscore the need for increased attention on replicating the diameter distribution of healthy collagens in tissue engineering scaffolds and allowing adequate supply of elements through permeation during ACL reconstruction procedures.

背景和目的在无血管或血管不足的组织中，通过扩散募集维持组织功能所需的元素，这与细胞外基质在健康和损伤中的渗透性高度相关。在这里，我们调查的牛前十字韧带（ACL）组织的胶原纤维直径分布对基质的水力渗透性的影响。基于健康的和受损的ACL组织之间直径分布明显不同的事实，我们的研究旨在研究这种可变性对水力渗透率的影响。方法以3D模式进行模拟根据从健康和受伤的组织样本（n = 3）获得的实际胶原蛋白长丝/原纤维直径分布重建的几何形状。流经纤维组织的流体是根据艾林根（Eringen）的微极性流体理论建模的，以确定涡旋粘度（m）和自旋梯度粘度（N）对水力渗透率的影响。结果计算结果表明，作为健康ACL组织复制品的模型的水力渗透率高于受伤者的模型，这表明细丝尺寸分布可能对通过韧带组织的液体和营养物运输起重要作用。