Effective UV/Ozone irradiation method for decontamination of hydroxyapatite surfaces.

The purpose of this study was to establish whether UV/ozone (O) irradiation method can effectively decontaminate hydroxyapatite surfaces, including those modified by the treatment with 30% phosphoric acid solution through morphological and chemical surface analyses (surface roughness, X-ray photoelectron spectroscopy and wettability), and to evaluate the response of osteoblast-like MC3T3-E1 cells to the modified hydroxyapatite surface decontaminated via this method. The amount of carbon and the contact angle of hydroxyapatite surfaces were significantly decreased by UV/O irradiation that lasted for ≥ 5 and ≥ 3 min, respectively ( < 0.01). Additionally, 7-day storage of HPO-modified hydroxyapatite surface decontaminated with 5-min irradiation did not affect contact angle values ( > 0.05). MC3T3-E1 cell proliferation, differentiation (as assessed by relative and mRNA levels), and mineralisation were significantly promoted on irradiated surfaces ( < 0.05). These findings show that UV/O irradiation for ≥ 5 min significantly decontaminated HPO-modified hydroxyapatite surface, improved its wettability, and facilitated osteoblast growth and function.