Self-assembly of collagen-mimetic peptide amphiphiles into biofunctional nanofiber.

Molecular assembly of protein and peptide is highly specific and frequently occurs in biological systems. Collagen, which is the most abundant component in extracellular matrix, can assemble into fiber and play an essential role in cell adhesion and growth. Since native collagen is difficult to modify and can engender pathogenic and immunological side effects, its application on tissue regeneration is limited. The preparation of collagen-mimetic materials, hence, is gaining interest in the field of tissue regeneration. Collagen peptides have been synthesized to mimic some properties of collagen, such as its triple helix. However, few studies have been done to prepare artificial collagen fiber to mimic its high-level structure and biofunctions. In this work, a novel collagen-mimetic peptide amphiphile (CPA) was prepared by conjugating a single hydrophobic tail with a collagen-mimetic peptide, supplemented with bioactive glycine-phenylalanine-hydroxyproline-glycine-glutamate-arginine (GFOGER). The physical studies indicated that the CPA had a collagen-mimetic triple-helical conformation and was able to self-assemble into nanofiber. In addition, the CPA conjugated with the integrin-specific GFOGER sequence was shown to promote collagen-mimetic cell adhesion and development. The self-assembled peptide nanofiber was shown to have the ability to structurally and biologically mimic native collagen fiber. We anticipate that this artificial collagen fiber holds great potential as collagen-mimetic materials for tissue regeneration applications.