Development of phosphate-treated PEEK implants with high osseointegration

Recently, various methods have been developed to enhance the bioactivity of polyether ether ketone (PEEK), limiting its clinical applications. But these methods have certain drawbacks, such as the potential impact on the mechanical properties and surface topography of PEEK and the need for specialized equipment. This study introduces a novel chemical surface treatment method, which is cost-effective and does not require any specialized equipment by the use of an alkaline wet process in combination with alkaline solutions and phosphorus-containing compounds. The effectiveness of this method was evaluated by investigating its effects on the surface topography of PEEK and conducting in vitro and in vivo experiments using MC3T3-E1 cells and rabbits. Scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry have confirmed the success of introducing phosphate groups on PEEK surface without altering its surface topography. The bioactivity of the phosphate-treated PEEK was demonstrated through mineralization assays using MC3T3-E1 cells and push-out tests with rabbits. Therefore, without the drawbacks of other methods previously mentioned, this method is capable of producing PEEK materials with high osseointegration without the drawbacks of the previously reported methods and may therefore be applied to various orthopedic implants.