Objective To explore the function of p53 on regulating the expression of miR-148b in lung cancer cell line PC-9 and its corresponding molecular mechanism and the impact on cell proliferation. Methods Transient transfection of p53 eukaryotic expressing plasmids into lung cancer cell line PC-9 was performed to establish a cell model over-expressing p53. RT-PCR was used to explicit the impact of p53 on the expression of miR-148b. A reporter vector containing miR-148b promoter was used to investigate the function of p53 on regulating the transcription of miR-148b. Low-expressing miR-148b by transfecting its specific inhibitors , a CCK-8 assay was performed to explore the influence of miR-148b on the lung cancer cell proliferation inhibited by p53. Results Over-expression of p53 promoted miR-148b expression in lung cancer cell line PC-9. P53 could increase the luciferase activity driven by miR-148b promoters. Knockdown of miR-148b attenuated the impact of p53 on inhibiting the proliferation of PC-9 cells. Conclusion P53 inhibits the proliferation of lung cancer cell line PC-9 partially depending on miR-148b.

Objective To explore the feasibility of the bilayer chitosan barrier membrane loaded with tannic acid(CS@TA)for guided bone regeneration by exploring the reactive oxygen species(ROS)scavenging ability,bio-compatibility,and antibacterial properties.Methods The single-layer chitosan(CS)film was prepared by self-e-vaporation,and the double-layer CS film was prepared by directional freezing and freeze-drying,and its microstruc-ture was observed by scanning electron microscope.The prepared CS bilayer membrane was grafted with tannic acid(TA)in different proportions,and the interaction between TA and CS bilayer membrane was analyzed by Fourier infrared spectrometer(FITR).The ROS scavenging ability was tested by 1,1-diphenyl-2-picrylhydrazyl(DPPH),and the double-layer membrane of loading TA scavenging efficiency of more than 90%was selected to continue the follow-up experiment.CCK-8 assay and lived dead staining were used to evaluate the survival rate of cell in each groups.MC3T3-E1 cells was adhesion the CS@TA barrier film for studying by SEM.Colony counting was per-formed to test its antibacterial performance against Escherichia coli(E.coli)and Staphylococcus aureus(S.au-reus).Results One side was the smooth,dense while other side was rough,loose and porous,with a longitudinal ordered porous structure in cross-section of the double-layer membrane of CS@TA.With the addition of TA,the ROS scavenging ability of the double-layer membrane first increased rapidly and then stabilized slowly.The results of CCK-8 and lived and dead cells staining showed that excessive TA addition significantly affected the biocompati-bility of the double-layer membrane.The counting results of bacterial dilution coating showed that compared with the double-layer membrane without TA loading,the double-layer membrane had certain antibacterial ability against E.coli and S.aureus when the appropriate amount of TA was added.Conclusion Thus the double-layer with ap-propriate TA loading has strong ROS scavenging ability,good biological performance,and certain antibacterial abil-ity for E.coli and S.aureus.