Lithium‐Functionalized Sulfonated Polyetheretherketone with Dual Osteogenic‐Angiogenic Property: A One‐Step Bioactivation Strategy for Enhanced Implants Osseointegration

Polyetheretherketone (PEEK) demonstrate exceptional suitability for bone implant applications, exhibit optimal mechanical performance, excellent tissue compatibility, remarkable chemical stability, and the ideal radiolucency of Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) scanning. However, bioinert surface of PEEK limits cellular integration and osteogenic activity. This study addresses this limitation through a novel one-step hydrothermal bioactivation strategy, integrating lithium ions onto sulfonated PEEK (Li-SPEEK) to confer dual biological activities facilitating both bone regeneration and osseointegration. In vitro, relative to pristine PEEK, lithium-functionalized surfaces significantly stimulate both osteogenic maturation of rat mesenchymal stem cells (BMSCs) and angiogenic activity in human umbilical vein endothelial cells (HUVECs) through lithium ion release. In vivo evaluations using rat bone implantation model and mouse air pouch model corroborate Li-SPEEK's superior performance in mitigating inflammatory responses, promoting vascularization, and facilitating osseointegration. This study presents an efficient one-step strategy for the design and fabrication of innovative multifunctional implants. Furthermore, Li-SPEEK demonstrate transformative potential for orthopedic implants due to its fast synthesis, cost-effectiveness, low cytotoxicity, desirable treatment effect, and flexible clinical implementation, underscore its significant research merit and clinical application prospects.