Novel vascular strategies on polyetheretherketone modification in promoting osseointegration in ovariectomized rats

The primary stability and final osseointegration of endosseous implants may be hindered by certain abnormal bone-metabolism conditions, such as osteoporosis. Polyetheretherketone (PEEK), which shows similar adjustable elastic modulus with cortical bone, is considered to be an ideal candidate to replace metallic implants, especially for osteoporotic bone. However, the bioinertness and poor osteogenic properties of PEEK fail to pave the way for clinical application. Here, a novel coating (EBE-SrSi) with bioactive elements on PEEK implants was generated via electron beam evaporation (EBE) to enhance the rapid osseointegration by inducing osteogenesis, as well as angiogenesis. In vitro, the dual Sr/Si ion modified surface exihibits a better osteo-inductive effect on the BMSCs derived from ovariectomized rats (rBMSCs-OVX). Furthermore, the modified samples also stimulated human umbilical vein endothelial cells (HUVECs) migration and angiogenesis. Finally, in the OVX rat bonedefect model, the EBE-SrSi group exhibited faster bone formation which might be attributed to the impact of the transformation of endogenous MSC accompanied by promotion of the angiogenic activity of endothelial cells. Our results unveiled the potential of dual Sr/Si modified PEEK in promoting osseointegration under osteoporotic conditions and will further broaden the adoption of PEEK materials in dental fields.