Activity Of Osteoblast-like Cells On ZrO₂Film Prepared By Catholic Arc Deposition

[Abstract] Objective: To prepare ZrO₂film by cathodic arc deposition （CAD），and to detect thecharacterizations of the ZrO₂film. Method: ZrO₂film was prepared on titanium by cathodic arcdeposition. The surface topography was characterized by scanning electron microscopy （SEM） andatomic force microscopy （AFM）. The element composition of the films was detected by X-rayphotoelectron spectroscopy （XPS）. The phase of films was identified by thin film X-ray diffraction（XRD）. Result: SEM view images show that the ZrO₂film was uniform, dense and smooth. AFM resultindicates that the ZrO₂film deposited by filtered cathodic arc deposition has a nanostructured surface.XRD analysis indicates the ZrO₂film were amorphous. XPS spectra of ZrO₂film shows C1s, O1s, Ti3p,Zr3d, Zr3p, Zr3s, and Zr4s peaks are observed. Conclusion: Amorphous ZrO₂film can be deposited onTi disks by cathodic arc deposition. The deposited ZrO₂film seems to be uniform, dense and smoothand has a nanostructured surface, which may contribute to its bioactivity. [Abstract] Objective: To evaluate the effect of ZrO₂film fabricated by cathodic arc deposition onadhesion and proliferation of osteoblast-like MG63cells. Method: Osteoblast-like MG63cells werecultured on ZrO₂film and Ti respectively. MTT was used to measure the number of cell attachmentafter1,6,12,24h of cultivation. Cell spreading was investigated by scanning electron microscopy（SEM）. The expression of actin on each sample was observed by immunofluorescence. Cellproliferation was assessed using a Cell Counting Kit-8（CCK-8） after1,4,7,10days of cultivation.Result: The MTT result showed that after6,12,24h of culture, the number of cell attachment on ZrO₂films was more than that on Ti （p <0.05）. The SEM study showed that MG63cells spread better onZrO₂films than on Ti. The fluorescence micrographs of actin stress fibers demonstrated thatwell-defined actin stress fibers distributed through the body of cells cultured on ZrO₂films afterincubated for12and24h. The CCK-8assay indicated that the ZrO₂films promoted the proliferation ofMG63cells. Conclusion: It was proved that the ZrO₂film fabricated by cathodic arc deposition was able to promote adhesion and proliferation of osteoblast-like MG63cells, suggesting that the ZrO₂filmis worth further consideration for orthopedic implant applications. [Abstract] Objective: To evaluate the effect of ZrO₂film fabricated by cathodic arc deposition ondifferentiation of osteoblast-like MG63cells. Method: Osteoblast-like MG63cells were cultured onZrO₂film and Ti respectively. After1,4,7,10days of incubation respectively, samples were collectedfor assay. ALP activity and gene expression of alkaline phosphates （ALP）, Type I collagen （COLI）,osteocalcin （OC） were assessed. The production of COLI at day4was evaluated byimmunofluorescence and the OC protein secretion after1,4,7,10days of culture were investigated byELISA assay. Result: The ALP activity increased steadily on both surfaces over the course ofincubation. By days4,7and10, the ALP activity of cells on ZrO₂films was significantly higher than onTi （p <0.05）. The ALP mRNA expression of cells on ZrO₂films was significantly higher than on Tiafter cultured for4,7and10days （p <0.05）. The COLI mRNA expression of cells on ZrO₂films wassignificantly higher than on Ti after cultured for4and7days （p <0.05）. The OC mRNA expression onZrO₂films was significantly higher than on Ti after7and10days of incubation （p <0.05）. Theproduction of type COLI by immunofluorescence showed that cells on ZrO₂films produced more COLIthan on Ti after4days of culture. The OC protein secretion on ZrO₂films was higher than on Ti after7,10days of culture. Conclusion: ZrO₂film was able to enhance induction of osteoblastic phenotype ofosteoblast-like MG63cells, which indicated that ZrO₂film may be a favorable bioactive biomaterial. [Abstract] Objective: To evaluate the effect of ZrO₂film fabricated by cathodic arc deposition onosteoclastogenic gene expression and their protein synthesis of osteoblast-like MG63cells. Method:Osteoblast-like MG63cells were cultured on ZrO₂film and Ti respectively. After1,4,7,10days ofincubation respectively, samples were collected for assay. The osteoclastogenic gene expression （OPG,RANKL） and their protein secretion were analyzed by real time PCR and ELISA respectively. Result:The OPG mRNA level on both surfaces appeared equal at day1and4（p>0.05）. After7and10days ofculture, the OPG mRNA level on ZrO₂films displayed higher than that on Ti （p <0.05）. The RANKLmRNA expression level on both surfaces showed no significant difference at day1and4（p>0.05）. However, the RANKL mRNA expression level of cells on ZrO2films appeared lower than on Ti at day7and10（p <0.05）. The OPG protein secretion on both surfaces appeared equal at day1and4（p>0.05）. The OPG protein secretion on ZrO2films was significantly higher than on Ti at day7and10（p <0.05）. The RANKL protein secretion on both surfaces appeared equal at day1and4（p>0.05）. TheRANKL protein secretion on ZrO2films was lower than on Ti at day7and10（p <0.05）. Conclusion:ZrO2film fabricated by cathodic arc deposition was able to enhance the expression of OPG geneexpression and protein synthesis while reduce the RANKL gene expression and protein synthesis,leading to increase in the ratio of OPG/RANKL, which may help contribute to the successful [Abstract] Objective: To explore the possible signal transduction passway mediating osteoblasticactivity on ZrO₂film fabricated by cathodic arc deposition. Method: Osteoblast-like MG63cells werecultured on ZrO₂film and Ti respectively. After6h,24h,4d,7d of cultivation respectively, sampleswere collected for assay. Gene expression of integrin β1, focal adhesion kinase （FAK）, extracellularregulated kinases （ERK, including ERK1and ERK2）, c-fos and c-jun were measured by real-time PCR.Result: After6h,24h and4d of culture, integrin β1mRNA expression on ZrO₂films wassignificantly higher than on Ti （p <0.05）. The gene expression of FAK on ZrO₂films was significantlyhigher than that on Ti at6h,24h and4d （p <0.05）. The gene expression of ERK1on ZrO₂films wassignificantly higher than on Ti at6h and24h （p <0.05）. The gene expression of ERK2on ZrO₂filmswas significantly higher than on Ti at6h,24h and4d （p <0.05）. The gene expression of c-fos on ZrO₂films appeared significantly higher than on Ti disks （p <0.05） at all time points. After cultured for6h,24h and4d, c-jun gene expression appeared significantly higher on ZrO₂films than on Ti disks （p <0.05）. Conclusion: The enhanced cell activity on ZrO₂films may be partially regulated by integrin β1mediated MAPK/ERK pathway.