(645d) Fibronectin-Mimetic Peptide-Amphiphile Nanofiber Hydrogels Support Increased Cell Adhesion and Promote ECM Production

The design of nanofiber scaffolds has been a key objective in tissue engineering as they structurally mimic the natural extracellular matrix (ECM) found in tissues. The continous cross talk between cells and the surrounding matrix ligands plays a crucial role during development and wound healing which leads to tissue regeneration and repair. In an attempt to provide a nanofiber scaffold with a ligand that can promote cell adhesion and ECM production, we propose the use of our peptide-amphiphile nanofibers as a potential scaffold for tissue engineering. A fibronectin-mimetic peptide sequence containing both the cell binding GRGDSP domain and the synergistic PHSRN domain has been recently developed in our group. It has been shown to be a specific ligand for the α₅β₁ integrin, and has been synthesized to a C₁₆ single-tailed peptide-amphiphile, PR_g (with a peptide headgroup of GGGSSPHSRN(SG)₅RGDSP). The PR_g peptide-amphiphiles self-assemble into nanofibers in an aqueous environment and form hydrogels. In this study, the PR_g hydrogels were characterized with cryo-scanning electron microscopy (cryo-SEM) and rheology measurements, and their surfaces were evaluated in terms of sustaining long term human umbilical vein endothelial cell (HUVEC) adhesion, cytoskeleton formation, and secretion of extracellular fibronectin. PR_g gels were compared to polyethylene glycol (PEG) gels, PEG gels functionalized with fibronectin as well as commercially available peptide hydrogels (PuraMatrix). Our results show that the PR_g hydrogels outperform the other gels evaluated in this study and therefore hold promise as scaffolds for tissue engineering.