Abstract

Vaginal defects resulting from surgical resection, congenital anomalies, or pelvic exenteration significantly impair reproductive functions and sexual health. Reconstructive surgery for full-thickness vaginal defects remains challenging by fibrotic scarring and inadequate restoration of native tissue architecture. To address this, we engineered a novel recombinant fusion peptide linking a collagen-binding domain (CBD, heptapeptide TKKTLRT) to human β-defensin-3 (hBD-3) using E. coli Origami (DE3). Recombinant CBD-hBD-3 promoted fibroblast proliferation and upregulated the expression of pro-angiogenic genes, while suppressing macrophage polarization toward a pro-inflammatory phenotype. Then, we fabricated CBD-hBD-3-functionalized collagen scaffolds (hCM) that enabled sustained local release of the peptide. In a rat model of full-thickness vaginal injury, hCM implantation significantly accelerated re-epithelialization, supported smooth muscle regeneration, enhanced vascularization, and attenuated fibrotic remodeling by reducing disorganized collagen deposition. Notably, hCM promoted epithelial repair through an EMT-associated process without inducing fibrosis, a balance that may be attributed to the concomitant upregulation of endogenous TGF-β inhibitors. In addition, CBD-hBD-3 competitively bound CD36 to disrupt the pro-fibrotic thrombospondin-1(TSP-1)-CD36-TGF-β axis, preventing fibroblast transition into an inflammatory phenotype. This work presents a multifunctional yet simple biomaterial strategy that actively reprograms fibroblast fate and disrupts core fibrotic pathways, offering a promising therapeutic collagen-based platform for scar-reduced tissue defect regeneration.