Surface modifications of polyetheretherketone using tantalum pentoxide layer attached with UV-induced sulfonate groups for the boosting of antibacterial and osteointegration activities

Background Polyetheretherketone (PEEK) is an attractive load‑bearing implant but suffers some limitations such as bioinertness or poor antibacterial property. To enhance its osteointegration and infection resistance using surface engineering modifications is thus necessary. Method Sulfonate‑bearing tantalum pentoxide (Ta₂O₅)/PEEK was prepared via three steps. Initially, PEEK was treated using concentrated H₂SO₄ with time interval of 1, 3, 5, 10, or 15 min, respectively, in order to create the microporous surface. Then hydrothermal growth of Ta₂O₅ film on PEEK at 180 °C for 24 h and thermal treatment on samples at 300 °C for 2 h were employed. Finally, UV‑initiated graft polymerization of sodium p -styrenesulfonate (NaSS, 1 M) on sample was carried out under UV-light irradiation with light wavelength of 365 nm at 90 min. The XRD, SEM, EDS, TEM and XPS analysis were carried out to examine the surface and physical properties of samples prepared in this study. Significant findings Amorphous or low crystalline Ta₂O₅ film grown on PEEK surface was observed from XRD/TEM‑SAED analysis. Their XPS results confirmed successful grafting of sulfonate functional groups on samples through UV-initiated graft polymerization by NaSS. Lower water contact of 32.68 ± 0.86° for sample under sulfuric acid treatment of 5 min was observed compared to pristine PEEK (113.15 ± 0.36°). The sample under sulfuric acid treatment of 5 min yielded the best overall osteogenic performance, good antibacterial reduction against Staphylococcus aureus and Escherichia coli , identifying it being the superior trade‑off for prospective orthopedic/dental applications.