Multi-functional PEEK implants enhance osseointegration in OVX rat by remodeling the bone immune microenvironment.

Osseointegration is significantly impeded in osteoporotic conditions due to the elevated levels of reactive oxygen species (ROS) and inflammation at the site of injury. To enhance bone regeneration in osteoporotic conditions, a modified polyether ether ketone (PEEK) implants was prepared, denoted as PEEK-PDA-Sr. The implants consisted of mussel adhesion layer with the conjugation of strontium (Sr) ions, which can constantly release Sr ions for up to 3 weeks. PEEK-PDA-Sr demonstrated excellent biocompatibility and effectively regulated intracellular ROS levels and macrophage differentiation. In addition, the PEEK-PDA-Sr facilitated the osteogenesis of bone marrow stromal cells (BMSCs). In the ovariectomized (OVX) rat model of osteoporosis, the PEEK-PDA-Sr exhibited raised osseointegration in the femoral bone defects. The PEEK-PDA-Sr can be used as an immunoregulator with enhanced osseointegration and osteogenesis both in vivo and in vitro, which provides an available approach to treat osteoporotic bone defects.