Synergistic activity of αvβ3 integrins and the elastin binding protein enhance cell-matrix interactions on bioactive hydrogel surfaces.

Engineering materials suitable for vascular prostheses has been a significant challenge, especially in promoting extracellular matrix (ECM) development within synthetic materials. Herein we have utilized two different elastin mimetic peptide sequences, EM-19 and EM-23, to provide a template for ECM deposition when covalently incorporated into scaffold materials. Both peptides contain the hexapeptide sequence VGVAPG, which interacts with the cell surface receptor known as the elastin binding protein (EBP). Additionally, EM-23 contains an RGDS sequence intended for the peptide's interaction with the α(v)β(3) integrin. We first confirm that the presence of both peptides approximates the synergistic mechanism for elastic fiber assembly in vivo, a process that utilizes both the EBP and α(v)β(3). Peptides were then grafted onto the surface of a poly(ethylene glycol) diacrylate (PEG-DA) hydrogel and their efficacy as templates for promoting cell adhesion, spreading, and elastin deposition was evaluated. Although both peptides were able to encourage smooth muscle cell (SMC) adhesion and elastin deposition over PEG-DA and PEG-RGDS controls, PEG-grafted EM-23 was proven to be the more promising motif for inclusion in synthetic substrates to be used in the engineering of vascular tissues, enhancing cell adhesion 60-fold and elastin content 2-fold compared with PEG-RGDS.