Nano-to-macroscale dual core-shell structured bioartificial ligament improves outcomes of anterior cruciate ligament reconstruction in rats: A proof-of-concept study

Over 400,000 anterior cruciate ligament (ACL) reconstructions are performed worldwide annually. The ability of patients to return to their pre-injury or adapted level remains limited. Although autografts and allografts are recognized as good choices for ACL reconstruction, postoperative complications are frequently reported. The emergence of artificial ligaments offers a promising strategy to solve these challenging medical conditions. However, artificial grafts composed of different materials have been associated with complications such as chronic effusions, synovitis, and graft failure to varying degrees. Although great progress has been made in modifying artificial grafts, the optimal strategy remains to be explored. Magnesium and recombinant spidroin have been proven to be promising implantable materials that can facilitate osteogenesis both in vitro and in vivo, thus exhibiting good potential for orthopaedic implants or grafts. In this study, a novel nano-to-macroscale dual core-shell structured bioartificial ligament integrating magnesium and recombinant spidroin has been developed using conjugate coaxial electrospinning. This innovative graft promoted graft-bone integration by facilitating early expression of osteogenic, neurogenic, and cell adhesion markers (e.g., BMP2, RUNX2, CGRP, and ITGA5) at the interface and accelerating new bone mineralization around the bone tunnel. These effects resulted in improved healing outcomes after ACL reconstruction in a rat model, suggesting significant clinical potential for future ACL applications.