Large bone defects remain a clinical challenge to be solved via emerging 3D scaffolds. For effective treatments, the bone scaffold should satisfy competing mechanical, biological, and chemical functions presenting a challenging design problem. Besides mainstream experimental studies, computational efforts exist in literature presenting scaffold designs with primarily optimized geometries focusing on geometry, pore size, and porosity (Dias et al., 2014; Poh et al., 2019) to deliver desired mechanical features in the form of stiffness and permeability. However, one of the most crucial metrics for scaffold design relates to bone regeneration based on mechano-biological behavior (Boccaccio et al., 2016; Metz et al., 2020) which is also experimentally validated. Similarly, in addition to mechano-biological tissue response, incorporation of the MSCs diffusion will provide more realistic approach for determining the most suitable scaffold geometry for effective bone repair (Geris et al., 2004). Therefore, to examine the effect of MSCs diffusion coupled with mechano-biology calculations, here we present a comparative parametric study for a regular structured 3D cubic scaffold structure with aligned square pores. The model is developed via COMSOL Multiphysics® software and a MATLAB interface script. Material properties are updated iteratively until the steady state cell concentration in the scaffold pores are obtained. The effect of diffusion on the bone regeneration is analyzed for scaffold architectures with different pore size values. The wall shear stress, fluid velocity, pressure and octahedral shear strain values were analyzed in detail. Initial results indicate that incorporation of stem cell diffusion leads to altered values of the mechano-biological response demanding optimal pore size values to be determined incorporating these effects for effective bone healing. To the best of our knowledge, this is the first detailed 3D scaffold analysis of coupled mechano-biology and cell diffusion processes and its effect on bone regeneration based on a coupled fluid flow-mechanical analysis of poroelastic scaffolds.
Boccaccio A. et al., Int. J. Biol. Sci. 12, 1-17 (2016)
Dias, M.R. et al., Medical Engineering & Physics. 36, 448–457 (2014).
Geris, L. et al., Journal of Biomechanics. 37, 763–769 (2004).
Metz, C. et al., Acta Biomaterialia. 101, 117–127 (2020).
Poh, P.S.P. et al., Sci Rep. 9, 9170 (2019).