Characterization of Sex-Based Differences in Integrin-Mediated Endothelial Cell Adhesion to Bioactive Hydrogels

Endothelialization promotes thromboresistance in blood-contacting devices, but biomaterial designs often overlook sex differences in the endothelialization processes. In this study, we elucidated sex differences in endothelial cell-material interactions through an investigation of the integrin-ligand interplay with biomaterial substrates and the corollary effects on cell adhesion and spreading. First, integrin expression of human coronary artery endothelial cells (HCECs) was characterized for age-matched donors (3 male, 3 female). Sex-based differences in integrin expression were identified, with notably higher α2β1, α5β1, and αVβ3 expression in female cells and higher α1β1 expression in male cells. On poly(ethylene glycol)-based hydrogel incorporating collagen or gelatin, female cells showed greater attachment on stiff substrates as compared to male HCECs, likely driven by greater α2β1, α5β1, and αVβ3 expression in female cells. Collectively, these results demonstrate sex-biased endothelial cell responses to bioactive hydrogels mediated by integrin interactions and highlight the importance of incorporating biological sex as a design variable in the development of blood-contacting biomaterials.