Surface Modification of Poly(ether ether ketone) by Simple Chemical Grafting of Strontium Chondroitin Sulfate to Improve its Anti-Inflammation, Angiogenesis, Osteogenic Properties

Besides inducing osteogenic differentiation, the surface modification of poly(ether ether ketone) (PEEK) is highly expected to improve its angiogenic activity and reduce the inflammatory response in the surrounding tissue. Herein, strontium chondroitin sulfate is first attempted to be introduced into the surface of sulfonated PEEK (SPEEK-CS@Sr) based on the Schiff base reaction between PEEK and ethylenediamine (EDA) and the amidation reaction between EDA and chondroitin sulfate (CS). The surface characteristics of SPEEK-CS@Sr implant are systematically investigated, and its biological properties in vitro and in vivo are also evaluated. The results show that the surface of SPEEK-CS@Sr implant exhibits a 3D microporous structure and good hydrophilicity, and can steadily release Sr ions. Importantly, the SPEEK-CS@Sr not only displays excellent biocompatibility, but also can remarkably promote cell adhesion and spread, improve osteogenic activity and angiogenic activity, and reduce the inflammatory response compared to the original PEEK. Therefore, this study presents the surface modification of PEEK material by simple chemical grafting of strontium chondroitin sulfate to improve its angiogenesis, anti-inflammation, and osteogenic properties, and the as-fabricated SPEEK-CS@Sr has the potential to serve as a promising orthopedic implant in bone tissue engineering.

Automated summary

In this study, strontium chondroitin sulfate was successfully introduced into the surface of poly(ether ether ketone) (PEEK) through a simple chemical grafting method. The modified PEEK material exhibited improved cell compatibility, osteogenic activity, and angiogenic activity, while reducing inflammation.