Mussel-Inspired Artificial Grafts for Functional Ligament Reconstruction

The development of an artificial graft with distinct osteogenetic activity to enhance osseointegration and to induce the formation of biomimetic tissue structure for ligament reconstruction remains a significant challenge. Inspired by mussels, biomimetic calcium phosphate apatite/polydopamine hybridized-polyethylene terephthalate (APA/PDA-PET) grafts were successfully prepared. The efficacy and mechanism of APA/PDA-PET grafts to induce osseointegration were systematically investigated. The results from the in vitro study indicated that the prepared APA/PDA-PET grafts support the attachment of bone marrow stromal cells (BMSCs) and stimulate the proliferation and osteogenic/angiogenic differentiation of BMSCs via activation of the PKC/p-ERK1/2 signaling pathway. In vivo, histological and radiological results further demonstrate that the APA/PDA-PET grafts significantly improve osseointegration by inducing the formation of new bone tissue and the fibrocartilage transitional zone compared with pure PET grafts. In addition, the pull-out strength of the APA/PDA-PET grafts is significantly higher than that of the pure PET grafts 12 weeks after surgery. These results suggest that this mussel-inspired biomimetic method is an effective strategy for modifying artificial grafts, and the prepared APA/PDA-PET grafts, which possess a beneficial interface, can significantly improve in vivo osseointegration for ligament reconstruction via the synergistic effect of polydopamine and apatite.