| Because the operating environment of the artificial joint is complex,it needs to bear multiple forms of loads,friction and wear,as well as the effects of oxidation and degradation in the human body.Therefore,medical artificial joint materials need to have good biocompatibility,wear resistance and oxidation resistance.In this paper,the in vitro acute biological toxicity of tea polyphenols /UHMWPE was compared and the toxicity level was evaluated,which laid a solid theoretical foundation for the following effects of irradiation cross-linking,antioxidant tea polyphenols and accelerated aging on the antioxidant mechanism of UHMWPE matrix and the rules of biological tribological behavior.By the methods of CCK-8,TP/UHMWPE powder acute biological toxicity in vitro experiments,the L929 mouse fibroblast cells placed in incomplete high sugar DMEM medium for culture,observation to the logarithmic phase after joining the TP/UHMWPE powder continues to develop,to a certain period of time after taking out the use of CCK-8 cytoxicity-Proliferation Test Box is used to detect the cell survival rate,and thus it is concluded that the actual cell survival condition.According to the experimental results,we can know that:Compared with the positive controlgroup,OD values measured by 0.01% and 0.03% of TP/UHMWPE and non-toxic pure UHMWPE showed no significant difference from the calculated RGR valuesm indicating no obvious cytoxicity in the experimental group,thus providing a theoretical basis for the follow-up study and application of TP/UHMWPE composite material.Composite materials were prepared by molding to explore the antioxidant mechanism of tea polyphenols and the tribological behavior of TP/UHMWPE.UHMWPE has been widely used as an artificial joint material.The wear resistance of UHMWPE is improved to a certain extent after irradiation cross-linking treatment.Therefore,after irradiation cross-linking,the matrix friction coefficient of UHMWPE increases,but the wear resistance increases.However,with the increase of tea polyphenol content,the friction coefficient does not change much,and the wear resistance improves with the increase of tea polyphenol content.Contrast after accelerated aging,not add tea polyphenols of UHMWPE matrix after aging before the wear morphology is far inferior to aging,and with the increase of content of tea polyphenol,the closer the wear morphology before and after accelerated aging,shows that tea polyphenols in the process of accelerated aging makes a substantial reduction in free radicals of UHMWPE matrix,and the lower level of substrate structure changed,so as to make the wear resistance increase,not add tea polyphenols of UHMWPE matrix of the main wear mechanism is abrasive wear,fatigue wear and adhesive wear,and add the UHMWPE matrix of the main wear mechanism is abrasive wear and fatigue wear.By comparing the mechanical properties of different components of tea polyphenols /UHMWPE before and after accelerated aging,it can be seen that accelerated aging will decrease the tensile strength,yield strength,and ball pressure hardness of the sample,and increase the elastic modulus and ball pressure creep depth.This is because the UHMWPE matrix without adding tea polyphenols becomes soft after accelerated aging.However,the addition of tea polyphenols will offset part of the trend that the mechanical properties do not decline because of accelerated aging. |
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