Development of 45S5/PEEK Bioactive Coatings by Cold Gas Spray for Orthopedic Implants

Cold Gas Spray (CGS) technology has allowed the development of biofunctional composite coatings composed of 45S5 and Polyetheretherketone (PEEK). The combination of a bioactive glass material embedded in a biocompatible polymeric matrix becomes this new composite in an interesting material for orthopedic applications since meet the biomechanical and biological requirements of an artificial implant. In the present study, blends of bioactive glass 45S5 and PEEK powder with different granulometry and 45S5/PEEK ratio have been prepared. These mixtures of powders have been deposited onto PEEK substrates by CGS with the goal of incorporating a bioactive additive to the biocompatible polymer, which can improve the bone-implant interaction of PEEK. The deposition efficiency (DE) and thickness of the coatings have been evaluated and from the results obtained, it was possible to conclude that DE and coating thickness are significantly affected by the granulometry and by the 45S5/PEEK ratio of the blends. By Scanning Electron Microscopy (SEM) inspection, it was observed that the use of blends with high 45S5/PEEK ratio led to the deposition of coatings with high content of 45S5 particles embedded in the polymeric matrix. Finally, the friction behavior of the coatings was analyzed performing ball-on-disk tests and these experiments showed that the presence of glass particles has a beneficial role in the wear resistance of the coatings.