Local and regional mechanical characterisation of a collagen-glycosaminoglycan scaffold using high-resolution finite element analysis

Artificial tissue growth requires cells to proliferate and differentiate within the host scaffold. As cell function is governed by mechano-sensitive selection, tissue type is influenced by the microscopic forces exposed to the cells, which is a product of macroscopically straining the scaffold. Accordingly, the microscopic strain environment within a CG scaffold is offered here. Using μμCT to characterise CG scaffold architecture, two high-resolution 3D FE models were used to predict the deformation mechanics. While also providing an analysis of region-specific features, such as relative density, pore diameters and microstructural elastic stability, the deformation patterns afforded strains to be inferred for seeded cells. The results indicate a regional dependence, in terms of architectural and mechanical properties. Specifically, the peripheral regions demonstrated the lowest volume fraction, the highest stress concentrations and the greatest potential for elastic instability. Conversely, the mid-region exhibited the most homogeneous environment. Based on the proviso of mechano-sensitive proliferation and differentiation, the findings suggest cell function will vary between CG scaffold regions. Further work should investigate the possibility of improving the fabrication process in order to deliver a construct in line with the mid-region, or alternatively, isolation of the mid-region may prove beneficial for cell culturing.