Engineering integrin-specific surfaces with a triple-helical collagen-mimetic peptide

• Published in: Journal of biomedical materials research. Part A Vol. 65A; no. 4; pp. 511 - 523
• Main Authors: Reyes, Catherine D., García, Andrés J.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15-06-2003
• Subjects: 3T3 Cells; Amino Acid Sequence; Animals; Antibodies; Avidin; Binding Sites; Biocompatible Materials - chemical synthesis; Biocompatible Materials - chemistry; biomimetic; Buffers; Cell Adhesion; Cell Line; Circular Dichroism; collagen; Collagen - chemistry; Focal Adhesions; Humans; integrin; Integrin alpha2beta1 - metabolism; Materials Testing; Mice; Molecular Mimicry; Oligopeptides - chemical synthesis; Oligopeptides - chemistry; Protein Conformation; Protein Structure, Quaternary; surface immobilization; Tissue Engineering - methods
• ISSN: 1549-3296; 1552-4965
• DOI: 10.1002/jbm.a.10550

Integrin‐mediated cell adhesion to extracellular matrix proteins anchors cells and triggers signals that direct cell function. The integrin α2β1 recognizes the glycine‐phenylalanine‐hydroxyproline‐glycine‐glutamate‐arginine (GFOGER) motif in residues 502–507 of the α1(I) chain of type I collagen. Integrin recognition is entirely dependent on the triple‐helical conformation of the ligand similar to that of native collagen. This study focuses on engineering α2β1‐specific bioadhesive surfaces by immobilizing a triple‐helical collagen‐mimetic peptide incorporating the GFOGER binding sequence onto model nonadhesive substrates. Circular dichroism spectroscopy verified that this peptide adopts a stable triple‐helical conformation in solution. Passively adsorbed GFOGER‐peptide exhibited dose‐dependent HT1080 cell adhesion and spreading comparable to that observed on type I collagen. Subsequent antibody blocking conditions verified the involvement of integrin α2β1 in these adhesion events. Focal adhesion formation was observed by immunofluorescent staining for α2β1 and vinculin on MC3T3‐E1 cells. Model functionalized surfaces then were engineered using three complementary peptide‐tethering schemes. These peptide‐functionalized substrates supported α2β1‐mediated cell adhesion and focal adhesion assembly. Our results suggest that this peptide is active in an immobilized conformation and may be applied as a surface modification agent to promote α2β1–specific cell adhesion. Engineering surfaces that specifically target certain integrin–ligand interactions and signaling cascades provides a biomolecular strategy for optimizing cellular responses in biomaterials and tissue engineering applications. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 65A: 511–523, 2003