Enhancement of Osteogenic Induction by LL37 Modified with a Collagen-Binding Domain In Vitro and In Vivo

Bone defect diseases, particularly those induced by inflammation, pose a challenge for the design of ideal drug-loading scaffolds that could facilitate bone repair and eliminate inflammatory pathogens. Antimicrobial peptides LL37 is considered a promising alternative loading drug due to its broad-spectrum antimicrobial effect and various bio-functions, including osteogenic induction. In this study, we synthesized modified LL37 by adding a collagen-binding domain (CBD) to achieve specific binding to collagen and a slow release pattern. The modified peptide was indicated to exhibit similar biological activities as natural LL37 on rat BMSCs, including promotion of migration activity, anti-inflammatory activity and osteogenic induction in vitro. Ectopic bone formation experiments further confirmed the angiogenesis and osteoinduction activities in vivo. Collectively, the results indicate that LL37-CBD may be a potential loading drug for preventative and curative applications in the treatment of inflammation-induced bone diseases.