Surface topography and wetting modifications of PEEK for implant applications

Polyetheretherketone (PEEK) is considered as a substitute for metallic implant materials due to its extremely low elastic modulus (3-4 GPa). Despite its good mechanical properties, PEEK exhibits a slow integration with the bone tissue due to its relatively inert surface and low biocompatibility. We introduced a dual modification method, which combines the laser and plasma surface treatments to achieve hierarchically patterned PEEK surfaces. While the plasma treatment leads to nanotopography, the laser treatment induces microstructures over the PEEK surface. On the other hand, plasma and laser treatments induce inhomogeneity in the surface chemistry in addition to the tailored surface topography. Therefore, we coated the structured PEEK surfaces with a thin alumina layer by pulsed laser deposition (PLD) to get identical surface chemistry on each substrate. Such alumina-coated PEEK surfaces are used as a model to investigate the effect of the surface topography on the wetting independent from the surface chemistry. Prepared surfaces bring advantages of enhanced wetting, multiscaled topography, proven biocompatibility (alumina layer), and low elastic modulus (PEEK as substrate), which together may trigger the use of PEEK in bone and other implant applications.