Evaluation of PEEK-Based Composites for Biomedical Applications by Performing Lubricated Sliding and Bone Growth Studies

We report the fluid lubrication properties of different Polyether ether ketone (PEEK) composites and their bone growth behavior by in vitro studies. Fluid tribological performance of PEEK- MAX (10%Cr2AlC), PEEK-(MAB)10%MoAlB, PEEK-10% DDGS500 (biochar of Distiller’s dried grains with soluble (DDGS) after pyrolysis at 500 °C), PEEK-10%Mo, and PEEK-10% Xonotlite composites were evaluated in Deionized and Distilled (DDI) water and Simulated Body Fluid (SBF) medium. The tribological performance of PEEK-10%Cr2AlC, PEEK-10%MoAlB, and PEEK-10%Mo composites against the stainless steel in both DDI water and SBF medium was better than PEEK. PEEK-10%DDGS composites showed similar wear performance under both water and SBF lubrication as compared to PEEK but it showed lower friction coefficient. This further shows that biochar can be integrated with the PEEK matrix. Detailed SEM analysis was used to document the apatite growth on the surfaces after treating them in SBF medium. By analyzing the microstructural images, we have identified DDGS500, Mo, and Xonotlite as promising additives for promoting apatite growth in SBF medium.