Bioactivation of PEEK via Plasma Immersion Ion Implantation

Abstract

Poly-ether ether ketone (PEEK) has emerged as a leading biomaterial for replacing metal implant components due to its outstanding physical properties. There has been interest in improving the bio-inert drawbacks of PEEK by the addition bioactive materials such as hydroxyapatite, either as composite fillers, or as a surface coating. Here we tested the use of Plasma Immersion Ion Implantation (PIII) as a surface treatment for PEEK to improve bioactivity by modifying its surface properties and also providing a convenient way to covalently immobilize biomolecules onto the surfaces of PEEK. The goal of this project was to improve bone cell responses to PEEK by modifying the surface properties and by bio-functionalizing the PEEK surfaces via the PIII treatment procedure to mimic the bone microenvironment. The physical properties of the surface created were characterized and the ability of the surface to covalently bind proteins was investigated by enzymatic assays. In addition, cell culture assays were performed to assess the attachment, proliferation, gene expression and bone matrix mineralization properties of the PIII treated PEEK surfaces. The PIII treated surface was shown to be significantly more bioactive compared to the untreated surface in most biological tests conducted. The covalent attachment of biomolecules was confirmed on the PIII treated surface and biofunctionalized surfaces were shown to improve bone formation. It is believed that these current findings will be helpful in broadening the usage of PEEK in the orthopaedic industry