Phytic acid/magnesium ion complex coating on PEEK fiber woven fabric as an artificial ligament with anti-fibrogenesis and osteogenesis for ligament-bone healing

Development of an artificial ligament possessing osteogenic activity to enhance ligament-bone healing for reconstruction of anterior cruciate ligament (ACL) is a great challenge. Herein, polyetheretherketone fibers (PKF) were coated with phytic acid (PA)/magnesium (Mg) ions complex (PKPM), which were woven into fabrics as an artificial ligament. The results demonstrated that PKPM with PA/Mg complex coating exhibited optimized surface properties with improved hydrophilicity and surface energy, and slow release of Mg ions. PKPM significantly enhanced responses of rat bone marrow stem cells in vitro. Moreover, PKPM remarkably promoted M2 macrophage polarization that upregulated production of anti-inflammatory cytokine while inhibited M1 macrophage polarization that downregulated production of pro-inflammatory cytokine in vitro. Further, PKPM inhibited fibrous encapsulation by preventing M1 macrophage polarization while promoted osteogenesis for ligament-bone healing by triggering M2 macrophage polarization in vivo. The results suggested that the down -regulation of M1 macrophage polarization for inhibiting fibrogenesis and upregulation of M2 macrophage po-larization for improving osteogenesis of PKPM were attributed to synergistic effects of PA and sustained release of Mg ions. In summary, PKPM with PA/Mg complex coating upregulated pro-osteogenic macrophage polari-zation that supplied a profitable anti-inflammatory environments for osteogenesis and ligament-bone healing, thereby possessing tremendous potential for reconstruction of ACL.

Automated summary

This study developed an artificial ligament with osteogenic activity by coating polyetheretherketone fibers with a phytic acid/magnesium ion complex. The artificial ligament showed improved surface properties, slow release of magnesium ions, and enhanced responses of bone marrow stem cells and macrophages. The ligament also inhibited fibrous encapsulation and promoted osteogenesis in vivo. The results suggest that the coating of phytic acid/magnesium ion complex has tremendous potential for reconstructing the anterior cruciate ligament (ACL) by creating a pro-osteogenic and anti-inflammatory environment.