Repair potential of self‐assembling peptide hydrogel in a mouse model of anterior cruciate ligament reconstruction

Abstract

Abstract Purpose Establishing zonal tendon‐to‐bone attachment could accelerate the anterior cruciate ligament reconstruction (ACLR) rehabilitation schedule and facilitate an earlier return to sports. KI24RGDS is a self‐assembling peptide hydrogel scaffold (SAPS) with the RGDS amino acid sequence. This study aimed to elucidate the therapeutic potential of KI24RGDS in facilitating zonal tendon‐to‐bone attachment after ACLR. Methods Sixty‐four C57BL/6 mice were divided into the ACLR + SAPS and ACLR groups. ACLR was performed using the tail tendon. To assess the maturation of tendon‐to‐bone attachment, we quantified the area of mineralized fibrocartilage (MFC) in the tendon graft with demeclocycline. Immunofluorescence staining of α‐smooth muscle actin (α‐SMA) was performed to evaluate progenitor cell proliferation. The strength of tendon‐to‐bone attachment was evaluated using a pull‐out test. Results The MFC and maximum failure load in the ACLR + SAPS group were remarkably higher than in the ACLR group on Day 14. However, no significant difference was observed between the two groups on Day 28. The number of α‐SMA‐positive cells in the tendon graft was highest on Day 7 after ACLR in both the groups and was significantly higher in the ACLR + SAPS group than in the ACLR group. Conclusion This study highlighted the latent healing potential of KI24RGDS in facilitating early‐stage zonal attachment of tendon grafts and bone tunnels post‐ACLR. These findings may expedite rehabilitation protocols and shorten the timeline for returning to sports. Level of Evidence Not applicable.

Keywords

• anterior cruciate ligament reconstruction
• enthesis
• RGDS
• scaffold
• self‐assembling peptide hydrogel