Integrin-specific bioadhesive surfaces using a triple-helical collagen-mimetic peptide

Integrin-mediated cell adhesion to type I collagen regulates various cell processes such as proliferation, migration, differentiation, and wound healing. Integrin α₂β₁ recognizes the glycine-phenylalanine-hydroxyproline-glycine-glutamate-arginine (GFOGER) motif in type I collagen. Recognition is entirely dependent on the triple-helical conformation of the ligand similar to that of native collagen. This work focuses on engineering α₂β₁-specific bioadhesive surfaces by immobilizing a triple-helical collagen-mimetic peptide incorporating the GFOGER binding sequence onto model non-adhesive substrates. Circular dichroism spectroscopy verified that this peptide adopts a triple-helical conformation in solution. Passively adsorbed GFOGER-peptide exhibited cell adhesion and spreading comparable to that observed on type I collagen. The involvement of integrin α₂β₁ in these adhesion events was verified with subsequent antibody blocking conditions and focal adhesion staining. Further experiments revealed α₂β₁-mediated cell adhesion and focal adhesion formation on three immobilized peptide surfaces. These results suggest that this peptide is active in an immobilized conformation and may be applied as a surface modification agent to promote cell adhesion. This triple-helical collagen-mimetic peptide represents a versatile and robust approach to engineering α₂β₁-specific surfaces for cell adhesion. Engineering surfaces that specifically target certain integrin-ligand interactions and signaling cascades allows us to optimize cellular response in biomaterials and tissue engineering applications.