(150t) LL37 and Collagen-Binding Domain-Mediated LL37 Binding with Type I Collagen: Quantification Via QCM-D

Antimicrobial peptide (AMP)-loaded biomaterials have the potential to promote wound healing while offering protection against infections. Our previous work introduced a collagen-binding domain (cCBD) derived from collagenase to the cathelicidin antimicrobial peptide, LL37, as an anchoring unit for collagen-based wound dressings. However, a direct comparison of unmodified LL37 and cCBD-LL37 binding to collagen has not been reported. In this study, we employed quartz crystal microbalance with dissipation monitoring (QCM-D), immunohistochemistry (IHC), and atomic force microscopy (AFM) to establish a type I collagen adsorbed layer on QCM-D sensors and quantify peptide-collagen binding. A successful collagen deposition protocol was developed using QCM-D, with IHC and AFM verifying collagen self-assembly. We investigated the influence of hydrophobicity on collagen adsorption by comparing SiO₂-coated hydrophilic and polystyrene (PS)-coated hydrophobic sensors. The hydrophobic surface exhibited greater collagen adsorption, suggesting its preferability for collagen layer establishment. While no significant difference was observed between LL37 and cCBD-LL37 binding to collagen, the cCBD-LL37 exhibited enhanced retention after PBS washing, highlighting the utility of cCBD as an anchoring unit to collagen. Our findings contribute valuable insights into cCBD-mediated AMP-binding mechanisms and offer an effective method for quantifying peptide-collagen interactions, providing important information for the development of advanced wound healing biomaterials.