Applied compression resulted in interstitial fluid flow with and without applied perfusion.
The resulting WSSs of each model were calculated at all saved time steps (20 in 1s) from fluid-solid interfaces. The median values of WSSs showed dynamic waveforms in all six multiphysics models during the full cycle length (Fig. 5). Bulk compressive strains of 5% and 10% resulted in substantial interstitial fluid flow that generated dynamic WSS throughout the scaffold even in the absence of applied perfusion, as shown in other FSI models of tissue engineered scaffolds (Marturano-Kruik et al., 2018; Zhao et al., 2015). Heat maps of the scaffold interior showed uniformly dispersed WSS throughout the scaffold at peak point (0.25s, Fig. 5), similar to our previous results simulating perfusion alone in irregular scaffolds (Liu et al., 2018) and that of others (Maes et al., 2012; Maes, Van Ransbeeck, Van Oosterwyck, & Verdonck, 2009). In addition, both histograms (Suppl. Fig. 3) and heat maps (Fig. 5) revealed that the majority of WSS values (1-100 mPa) were within the physiological range (Maes et al., 2012; McCoy & O’Brien, 2010; Sladkova & de Peppo, 2014).