Calcium Hydrogen Phosphate（CaHPO₄·2H₂O）and Antibiotic-modified Polyetheretherketone（PEEK） Are Used To Antibacterial And Enhance Osseointegration

Polyetheretherketone（PEEK）is an attractive medical high-performance engineering material in biomedical field,with excellent biocompatibility,low elastic modulus close to cortical bone,chemical corrosion resistance,self-lubricity,high temperature resistance and fatigue resistance.Currently,medical consumables made of PEEK have been widely used in the medical field,especially in orthopedics and stomatology.The emergence of PEEK provides a rich and increasingly extensive choice for implantable devices.However,the biological inertia of PEEK prevents it from integrating with surrounding normal bone tissue,especially that the implant areas are infected with bacteria.The infection of the implant can lead to the loosening of the implant and even induce the failure of bone integration and the serious infection spread.Although great progress has been made in antibacterial drugs and artificial materials,some deficiencies are also present in the field of antibacterial implants.Therefore,in order to improve the efficacy of PEEK implants,improvement of implants,promotion of osseointegration,prevention and even the control of infection are important and feasible steps in the treatment of orthopedic implants.In the first part of this study,a cyclic controlled layer-by-layer deposition（LBL）method was established to rapidly construct the calcium hydrogen phosphate(（CaHPO₄·2H₂O）（CaP）layer containing gentamicin sulfate（GS）on the PEEK surface,and the CaP and GS modified PEEK was obtained and named as PEEK/CaP-GS.CaP and GS modified PEEK by the repeating LBL cycle of 3,6,or 9 times was applied to prepare PEEK/ CaP-GS,which are known as PEEK/ CaP-GS * 3,PEEK/ CaP-GS * 6and PEEK/ CaP-GS * 9 according to cycle numbers.The morphology,structure and surface characteristics of different modified PEEK/CaP-GS were investigated in detail.In the second part,all PEEK/CaP-GS samples showed excellent and sustained antibacterial properties through in vitro antibacterial experiments.Cytological experiments revealed the good biocompatibility of PEEK/CaP-GS and its ability to promote osteogenic differentiation.In the third part of the experiment,the combination of in vivo animal model,bone morphological measurement and histological analysis showed that PEEK/CaP-GS had the ability to control bone tissue infection and promote bone integration.In this paper,a simple and effective new modification approach of PEEK was established,and its antibacterial function and biological function of enhancing osseointegration ability were endowed to meet the requirements of clinical application.