Work

Immunoregulative coating for scarless healing in anterior cruciate ligament reconstruction

Year: 2024

Type: article

Abstract: Polyethylene terephthalate (PET) artificial ligaments are widely used in anterior cruciate ligament (ACL) reconstruction due to their high tensile strength. However, bone tunnel enlargement around PET ligaments poses a risk for surgical failure. PET's inert surface, lower bioactivity, and mechanical abrasion trigger an M1 macrophage-mediated inflammatory response, leading to excessive, disorganized scar tissue. This scar tissue creates a space-occupying effect at the interface, obstructing graft-bone integration and contributing to bone tunnel enlargement. To address this issue, we developed a multi-layered immune-regulating hydrogel coating for scar-free PET-bone integration. Comprising gelatin methacrylate (GelMA), polyethyleneglycol diacrylate (PEGDA), and sulfated polysaccharide (SCS), the hydrogel forms a hydrogen-bonded lubricating layer to reduce friction. The sustained release of SCS also down-regulates M1 macrophage polarization, inhibiting early scar formation. By eliminating the space-occupying effect of scar tissue, SCS subsequently promotes M2 macrophage polarization. This shift releases endogenous factors that enhance blood vessel formation and new bone growth, ultimately achieving high-quality graft-bone integration. The application of this multi-layered, inflammation-modulating hydrogel coating not only removes scar tissue barriers but also improves graft-bone integration through enhanced angiogenesis and osteogenesis. Moreover, it avoids the overuse of exogenous growth factors and potential complications, offering a more convenient and feasible therapeutic strategy.

Source: Bioactive Materials

DOI: 10.1016/j.bioactmat.2024.11.007