Modification of the cell adhesion and hydrophilic characteristics of poly(ether-ether-ketone) by 172-nm Xenon excimer radiation

BACKGROUND: Poly-ether-ether-ketone (PEEK) has biomechanical and chemical properties that are excellent for biomedical applications; however, PEEK adhesion to bone or chondral tissue proceeds slowly due to poor hydrophilicity and other surface characteristics. OBJECTIVE: We investigated the structural change, hydrophilicity, and cytocompatibility of a PEEK surface after 172-nm xenon excimer UV-irradiation. METHODS: The surface characteristics before and after irradiation were evaluated by contact angle and ATR-FTIR measurements. Mouse osteoblast-like cells (MC3T3-E1) were cultured on PEEK plates and collected after 6, 12 and 24 h for cell adhesion analysis by crystal violet staining (CVS) and scanning electron microscopy (SEM). RESULTS: UV-irradiation improved PEEK surface hydrophilicity, as indicated by a significant drop in water contact angle (p<0.05). Irradiated PEEK showed additional peaks around 3370 cm^-1 and 1720 cm^-1, highlighting the generation of hydroxyl and carbonyl groups. CVS and SEM revealed improved adhesion to the PEEK surface after UV-irradiation. CONCLUSION: Our results suggest that 172-nm UV-irradiated PEEK may be used in biomedical applications that require good cell adhesion.