3D printed polyetheretherketone bone tissue substitute modified via amoxicillin-laden hydroxyapatite nanocoating

A hydroxyapatite (HA) nano-coated polyetheretherketone (PEEK) bone tissue scaffold modified with amoxicillin (AMX) was developed by 3D printing, modified hydrothermal method and impregnation. The morphology of the HA coating and the effect of the coating on mechanical properties, cytocompatibility and antibacterial properties were then investigated. Results found that the morphology of HA coating on the PEEK scaffold could be controlled by adjusting reaction temperature or/and time. Moreover, the HA coatings obtained by reacting at 120 °C, pH 12 for 12 h, were the ordered arrangement of nanorods, similar to the ordered arrangement of HA in natural bone tissue. Mechanical testing results demonstrated no adverse effect of coating and modified process on the inherent mechanical properties of PEEK. Moreover, the compressive yield strength and Young's modulus of the scaffolds were 11.23 ± 0.88 and 129.18 ± 8.10 Mpa, which could meet the mechanical requirements of native bone tissue. The cytocompatibility experiment with rabbit adipose-derived stem cells performed that the fabricated process and scaffolds were non-toxic, and cellular adhesion ability was enhanced after modification. The antibacterial properties of the AMX-modified scaffold were evaluated, and results confirmed that AMX could be loaded on the scaffold and released during cultivation to show excellent antibacterial properties. In conclusion, the fabricated modified HA-coated PEEK scaffold with AMX has great potential as a bone substitute in clinical application.