Effect of ultraviolet rays on the re-activation of the physicochemical properties and bioactivity of aging titanium surface / 中国组织工程研究

ABSTRACT

BACKGROUND:The physicochemical properties and bioactivity of titanium surface will degrade with time because of the aging phenomenon,affecting the efficiency of implant-bone osseointegration.Therefore,the re-activation of the implant surface physicochencical properties and bioactivity is important.OBJECTIVE:To investigate the re-activation effect of ultraviolet rays on aging titanium surface.METHODS:Sand-blasted and acid-etched titanium discs were divided into three groups randomlyGroup A was new titanium surface,Group B was stored in a sealed container for 4 weeks,Group C was treated with ultraviolet rays for 15 minutes after stored in the sealed container for 4 weeks.The surface roughness,elemental composition and surface energy of the titanium surface were examined by optical profilometer,X-ray photoelectron spectroscopy and contact angle measuring device,respectively.The bioactivity of the titanium surface was examined by cell culture experiments.MG63 osteoblast-like cells were cultured on the different titanium surfaces.After 30 minutes,1,2,4 hours of incubation,the cells were strained with Hoechst33342 fluorescence,and initial attachment of cells was evaluated by measuring the amount of cells attached to the titanium surface.The proliferation of cells was quantified in terms of cell density at 1 and 3 culture days using tetrazolium salt (MTS)-based colorimetry.RESULTS AND CONCLUSION:There was no obvious difference in the surface roughness of the three groups,and ultraviolet treatment did not change the surface morphology of titanium surface.X-ray photoelectron spectroscopy showed that the C element content of group A and group C was lower than that of group B (P ＜ 0.05),and the content of Ti,O,N elements was significantly higher than that of group B (P ＜ 0.05).No difference in the surface element composition between group A and group C was found.Both of the surface contact angles of group A and group C were Oo,but in group B,the value was 115°.The number of initially attached cells of group A and group C was significantly higher than that of group B after incubated 30 minutes,1,2 and 4 hours (P ＜ 0.05),and no difference between group A and group C was found.The proliferation of cells of group A and group C was significantly higher than that of group B after incubated 1 and 3 days (P ＜ 0.05),but no difference between group A and group C was found.In conclusion,ultraviolet rays show good effects on the re-activation of the aging titanium surface,which can reduce hydrocarbon contamination and recover the high surface energy to increase cell adhesion and proliferation.