Multifunctional peptide nanofiber coatings enhance bone regeneration on xenograft materials

Conventional bone grafts such as xenografts, allografts, and synthetic substitutes are widely used in regenerative dentistry, but their biological performance remains suboptimal. To address this limitation, this study investigates the effect of multifunctional peptide amphiphile (PA) nanofiber coatings on graft bioactivity. Peptide amphiphile molecules incorporating osteoinductive (DGEA-PA), mineralization-promoting (EEE-PA), adhesive (DOPA-PA), and antimicrobial (GL13K-PA) sequences were synthesized via Fmoc-based solid-phase peptide synthesis. The combined PA formulation was self-assembled into nanofibers and used to functionalize xenograft, allograft, and synthetic hydroxyapatite-based grafts. In vitro assays with human dental pulp stem cells (DPSCs) assessed adhesion, viability, osteogenic gene expression, alkaline phosphatase (ALP) activity, and mineralization. In vivo performance was evaluated in a rabbit calvarial critical-sized defect model using micro-CT and histology. Peptide-coated grafts significantly enhanced early cell adhesion and proliferation compared to unmodified controls. qRT-PCR revealed upregulation of osteogenesis-related genes (RUNX2, OPN, COL1A1), especially in peptide-treated groups. ALP activity and calcium deposition were markedly increased on PA-functionalized grafts. In vivo, micro-CT and histological analysis demonstrated greater bone volume, trabecular maturation, and integration in peptide-treated defects, particularly in the PA nanofiber-only and peptide-coated xenograft groups. Functionalization of conventional bone grafts with a tailored peptide amphiphile nanofiber mixture improves cellular response, osteogenic differentiation, and bone regeneration. This strategy offers a minimally invasive and translationally relevant approach for enhancing graft biofunctionality in bone repair applications.