Mechanotransduction in small intestinal submucosa scaffolds: fabrication parameters potentially modulate the shear-induced expression of PECAM-1 and eNOS.

In small intestinal submucosa (SIS) scaffolds for functional tissue engineering, the impact of scaffold fabrication parameters on cellular response and tissue regeneration may relate to the mechanotransductory properties of the final arrangement of collagen fibres. We previously proved that two fabrication parameters, (a) preservation (P) or removal (R) of a dense collagen layer present in SIS, and (b) SIS in a final dehydrated (D) or hydrated (H) state, have an effect on the micromechanical environment of SIS. In a continuation of our studies, we herein hypothesized that these fabrication parameters also modulate early mechanotransduction in cells populating the scaffold. Mechanotransduction was investigated by seeding human umbilical vein endothelial cells (HUVECs) on scaffolds, exposing them to pulsatile shear stress (12 ± 4 dyne/cm2 ) for 1 h (n = 5) in a cone-and-plate shear system, and evaluating the expression of the mechanosensitive genes Pecam1 and Enos by immunofluorescence and qPCR. Expression of mechanosensitive genes was highest in PD grafts, followed by PH and RH grafts. The RD group had similar expression to that of unsheared control cells, suggesting that the RD combination potentially reduced mechanotransduction of shear to cells. We concluded that the two fabrication parameters studied, which modify SIS micromechanics, also potentially modulated the early shear-induced expression of mechanosensitive genes in seeded HUVECs. Our findings suggest that fabrication parameters influence the outcome of SIS as a therapeutic scaffold.