Selective Responses Of Human Gingival Fibroblasts And Bacteria On Carbon Fiber Reinforced Polyetheretherketone With Multilevel Nanostructured TiO₂

【Objective】In this study,titanium plasma immersion ion implantation（PIII）was used to modified the carbon-fiber-reinforced polyetheretherketone（CFRPEEK）surface to construct a unique multilevel TiO₂ nanostructure.Here,we aimed to investigate the selective responses of human gingival fibroblasts（HGFs）and bacteria on this modified surface in vitro.【Material and Methods】1.Construct the unique multilevel TiO₂ nanostructure by using the PIII technology and characterize the morphology and surface composition by field-emission scanning electron microscopy（FE-SEM）and X-ray photoelectron spectroscopy（XPS）.2.Detect the viability,proliferation,adhesion,migration and collagen secretion ability of HGFs on the modified surface and further investigate the related mechanism.3.Evaluate the fibronectin adsorption on both surfaces by protein adsorption assay.4.Investigate antibacterial properties of the modified surface towards Streptococcus mutans,Fusobacterium nucleatum and Porphyromonas gingivalis by the spread plate test,fluorescence staining and SEM observation.【Results】1.Successfully fabricate unique multilevel TiO₂ nanostructure on CFRPEEK;samples before and after modification entitled as CFRPEEK and Ti-120.2.Ti-120 groups show good biocompatibility and better promote the HGFs adhesion,proliferation,migration and collagen secretion ability.Additionally,the modified surface facilitates the expression of adhesion-related genes and protein.3.Ti-120 is more favor for fibronectin adsorption.4.The structured surface exhibits sustainable antibacterial properties towards Streptococcus mutans,Fusobacterium nucleatum and Porphyromonas gingivalis.【Conclusions】1.The nanoscale surface can greatly influence the synthesis of ECM and regulate the expression of integrins,thus directly regulating cell behaviors,such as migration,proliferation and focal adhesion formation of HGFs.2.The structured surface exhibits sustainable antibacterial properties towards Streptococcus mutans,Fusobacterium nucleatum and Porphyromonas gingivalis.