Abstract
Collagen has long been one of the top targets for biomimetic design due to its superior structural and functional properties. Significant progress has been achieved to construct self-assembling peptides to mimic the fibrous nanostructure of native collagen, while it is still very demanding to fabricate peptide assemblies that can recapitulate both structural and biofunctional features of collagen. Herein, collagen-like peptides have been synthesized to contain negatively charged amino acids as the binding groups of lanthanide ions and the integrin-binding motif GFOGER. The simultaneous inclusion of negatively charged amino acids in the middle as well as at both terminals drives the peptides to self-assemble to form well-ordered nanofibers with distinct periodic banding patterns specifically mediated by lanthanide ions. The aggregation tendency and the morphology of the final assembled materials for the peptides are modulated in a pH-cooperative manner, which well mimics the pH-dependent fibrillogenesis of Type I collagen. The utilization of lanthanide ions in the system not only offers a convenient external stimulus but also functionalizes assembled materials with excellent luminescent features. Most notably, the lanthanide-triggered peptide assembled nanomaterials possess good cell adhesion properties, which resemble the biological function of collagen. This peptide-Ln3+ system provides a facile and potent strategy to generate nanofibers that mimic both the structural and functional properties of natural collagen. These novel pH-responsive, luminescent, and biofunctional collagen mimetic nanofibers open fascinating opportunities in the development of improved functional biomaterials in tissue engineering, drug delivery, and medical diagnostics.