Antibacterial Properties Research On HAPw/nmZnO-nmCaO Composite Bone Repair Material In Vitro

Objective:A new composite bone repair material——hydroxyapatite whisker composite nanometer zinc oxide and nanometer calcium oxide(HAPw/nmZnO-nmCaO)was prepared.The antibacterial properties of HAPw/nmZnO-nmCaO were studied and its antibacterial mechanism was discussed.Methods:The suspension of HAPw,Bio-oss,HAPw/nmZnO-nmCaO materials with a concentration of 1 mg/ml was prepared with sterile pure water as experimental group,and the sterile pure water as blank control group.The antibacterial properties of S.aureus,P.aeruginosa and E.coli were detected and compared between different groups by the colony formation unit(CFU)counting method.The changes of plaque biofilms in HAPw/nmZnO-nmCaO group and blank control group were observed by scanning electron microscopy(SEM).HAPw/nmZnO-nmCaO material suspensions with sterilized pure water of 0.5 mg/ml,1.0 mg/ml,1.5 mg/ml,2.0 mg/ml,respectively,The Zn2+,Ca2+reagent kit detected the release concentrations of the material suspensions at different concentrations at 24 H,1 W,2 W,3 W,4 W at Zn2+ and Ca2+,The antimicrobial properties of Staphylococcus aureus,Pseudomonas aeruginosa and Escherichia coli after the release of 4W ions from different concentration groups were detected by CFU method to investigate the antimicrobial mechanism of HAPw/nmZnO-nmCaO.Results:The material group of HAPw/nmZnO-nmCaO was significantly lower than that of HAPw,Bio-oss and blank control group(P<0.001).There was no difference between HAPw,Bio-oss,and blank control groups(P>0.05).Under SEM,strong plaque biofilms were formed in three control groups.bacteria were closely connected and stacked with each other.The bacterial adhesion of the three bacteria in the HAPw/nmZnO-nmCaO group was reduced,and the formation of plaque biofilm was inhibited.HAPw/nmZnO-nmCaO material suspensions in different concentration groups gradually increased the release of Zn2+ and Ca2+ with increased concentration and time.The release of Zn2+is close to the maximum when the material liquid is configured around 2w,and then tends to stabilize;The release of Ca2+is close to maximum when the material liquid is configured around 1w,and then tends to stabilize.Tablet colony counts in different concentration groups gradually decreased with Zn2+increasing concentration(P<0.05).Conclusions:HAPw/nmZnO-nmCaO has an inhibitory effect on the growth of Staphylococcus aureus,Pseudomonas aeruginosa and E.coli,and also has an inhibitory effect on the formation of three bacterial biofllms;The release of Zn2+ and Ca2+ in the suspension of HAPw/nmZnO-nmCaO gradually increase with time and material concentration increase.The release of Zn2+is one of the antibacterial mechanisms of HAPw/nmZnO-nmCaO.