Effects Of Two New Room Curing Polymethyl Methacrylate On Proliferation And Apoptosis Of L929 Cells

Objective:In view of the shortcomings of traditional room curing polymethyl methacrylate(PMMA),such as high brittleness,poor toughness and rough surface,which is easy to be colonized by bacteria,Ag Nanoparticles(AgNPs)and potassium titanate whiskers(PTW)were used to enhance the antibacterial and mechanical properties of room curing PMMA.In this way,the room curing PMMA reinforced by AgNPs(AgNPs-PMMA)and the room curing PMMA reinforced by PTW-AgNPs(PTW-AgNPs-PMMA)were synthesized.This study tested and compared the effects of the two new materials on the proliferation,oxidative damage and apoptosis of mice fibroblasts(L929),in order to illustrate their biocompatibility and provide new ideas for their application in the field of prosthodontics.Methods:AgNPs-PMMA and PTW-AgNPs-PMMA were synthesized by chemical and physical methods.The leaching liquor of the above materials were co cultured with L929 cells for 24 hours,and the proliferation was detected by MTT colorimetry to explore their effects on the proliferation of L929 cells in vitro.meanwhile,the content of reactive oxygen species(ROS)was detected to observe the effects of the leaching liquor on the oxidative damage of L929 cells.Quantitative Real-time PCR(qPCR)was used to test the effect of leaching liquor on the expression of apoptosis gene(Caspase-3、8、9)in L929 cells.Results:AgNPs-PMMA and PTW-AgNPs-PMMA compound materials were successfully synthesized.After cultured with L929 cells for 24 hours,the AgNPs-PMMA group and PTW-AgNPs-PMMA group inhibited the proliferation of L929 cells to a certain extent,but there was no significant difference with PMMA group.After calculation,the relative growth rate(RGR)of them was between 75% and 100%.According to the ISO 10993-5 standard,the cytotoxicity rating was 1.So it was preliminarily determined that these two compound materials had no cytotoxicity.The content of ROS in L929 cells in the the AgNPs-PMMA group and PTW-AgNPs-PMMA group was higher than that in the negative control group(P < 0.001),but there was no significant difference between them and PMMA group.The results of qPCR showed that the expression of Caspase-3 and Caspase-8 in PTW-AgNPs-PMMA group was higher than that in negative control group,and the expression of Caspase-3 was higher than that in PMMA group(P < 0.01).However,the expression of Caspase-3 in AgNPs-PMMA group was higher than that in negative control group(P < 0.05),and there was no difference between AgNPs-PMMA group and PMMA group.Conclusion:In this study,AgNPs-PMMA,PTW-AgNPs-PMMA and commercial PMMA can inhibit the proliferation of L929 cells to some extent,but they still belong to the category of non cytotoxic,and promote the oxidative damage and apoptosis of L929 cells.Among them,PTW-AgNPs-PMMA has more obvious effect on apoptosis of L929 cells,but it is found that the addition of AgNPs and PTW has no significant effect on ROS production of the original PMMA.In conclusion,there is no significant difference in the biocompatibility between AgNPs-PMMA and PMMA,but PTW-AgNPs-PMMA may enhance the expression of apoptosis genes compared with PMMA,and its biocompatibility needs further experimental exploration.