Polyetheretherketone fibers woven fabrics coated nanostructured silicon nitride and load EGCG as artificial ligaments for promoting ligament-bone integration

Design of an artificial ligament with osteogenic activity to promote ligament-bone integration for an-terior cruciate ligament (ACL) reconstruction remains a huge challenge. In this work, polyetheretherke-tone fibers with nanostructured silicon nitride coating (PSN) and loading epigallocatechin gallate (EGCG) were woven into fabrics (PSN@EG) for artificial ligament application.The in vitro experiments confirmed that PSN@EG significantly upregulated M2 macrophage polarization that promoted secretory of anti-inflammatory cytokines while downregulated M1 macrophage polarization that inhibithed secretory of pro-inflammatory cytokines. Moreover, PSN@EG remarkably improved osteoblastic differentiation of rat bone marrow mesenchymal stem cells (BMSC) while suppressed osteoclastic differentiation of rat bone marrow-derived macrophages (BMM) in macrophage condition medium. The in vivo experiments revealed that PSN@EG promoted new bone formation for ligament-bone integration that inhibited fibrous encap-sulation formation. It could be suggested that the synergistic effects of the optimized surface charactieris-tics (e.g., nano-micro topography), and sustained release of Si ions and EGCG caused the immunomod-ulatory of PSN@EG, which improved pro-osteogenic macrophage polarization that provided a favorable anti-inflammatory immune environment for enhancing osteogenesis while inhibiting osteoclastogenesis. In summary, PSN@EG with immunomodulatory significantly promoted osteoblastic differentiation while suppressed osteoclastic differentiation, thereby facilitating osteogenesis for ligament-bone integration. As a novel artificial ligament, PSN@EG has tremendous potential for ACL reconstruction.(c) 2022 Elsevier Ltd. All rights reserved.

Automated summary

In this study, an artificial ligament with osteogenic activity was designed to promote ligament-bone integration for ACL reconstruction. The artificial ligament, composed of polyetheretherketone fibers with nanostructured silicon nitride coating and loaded with epigallocatechin gallate, demonstrated immunomodulatory effects that promoted osteoblastic differentiation and suppressed osteoclastic differentiation. The optimized surface characteristics and sustained release of Si ions and EGCG contributed to the improved pro-osteogenic macrophage polarization and provided a favorable anti-inflammatory immune environment. This novel artificial ligament has great potential for ACL reconstruction.