The Effect Of The Titanium Modified By RGD Peptide Layer By Layer Self-assembling On The MC3T3-E1

Objective:The scholars have proposed that biological implant materials modification can significantly promote cell growth,change cell behavior and promote osseointegration.The RGD polypeptide was fixed on the surface of the implant by layer by layer self-assembly method,and the biological activity of the implant was given.In this study,the effects of RGD peptide on the adehesion,adhesion,proliferation and differentiation of osteoblasts were studied.Method:RGD polypeptide modified titanium plate by LBL,and then to study its effects on osteoblasts.In this study,RGD peptide was fixed on the surface of titanium plate self-assembly.Scanning electron microscopy was used to observe the surface morphology of the material.And X ray energy spectrometer was used to analyze surface elements by X ray energy spectrometer.The cultured MC3T3-E1 cells on the titanium surface RGD modified then observe adhesion morphological cells under scanning electron microscope;MTT method(MTT)to detect the influence of cell adhesion and proliferation;alkaline phosphatase(ALP)activity and alizarin red test osteoblast differentiation;real-time fluorescence quantitative PCR(RT-qPCR)technique for the detection of osteocalcin(OC),Osteoprotegerin(OPG)expression.Results:1.SEM observation of smooth titanium plate group(PT)and uniform surface fissure structure is clear,NaOH titanium group(NT)surface fracture structure is not obvious,like small pore structure;the titanium group RGD peptide modified(RT)surface structure after grinding without obvious traces of similar small bulges,and a network shop in the surface.2.SEM observation of 12h cells in RT group were polygonal,stretch,showing a large number of filopodia,cell spreading status is significantly better than the other two groups;3.MTT showed that the adhesion rate of RT group was the highest,the PT group and the control group there was no significant difference in the rate of adhesion,adhesion of cells in NT group was the lowest,the difference was statistically significant;group RT cell proliferation rate were higher than those of the other three groups(P<0.05),Id and 3d are the most obvious.4.alkaline phosphatase activity showed that ALP activity in RT group was higher than that in PT group and NT group,but there was no significant difference between 7d group and 10d group.The activity of alkaline phosphatase 14d in RT group was higher than that in the other three groups(P<0.05)5.alizarin red staining of NT group and RT group with orange red nodules,RT group was the most obvious calcium nodules.6.Detection of 7d RT-qPCR,RT group expression of osteocalcin mRNA was higher than that of PT group and NT group,but no significant differences appeared;expression of osteocalcin in the experimental group the 14d expression was significantly higher,the difference was significant;in the cell culture of 7d and 14d,NT group and RT group showed high expression of osteoprotegerin mRNA,have statistical significance.Conclusion:Osteoblasts cultured in vitro,which directly reflects the changing process of cells in vivo.The microscopic appearance under electron microscope RGD modified titanium plate can change the titanium sheet,X ray spectrometer analysis of surface elements of change,that is fixed on the titanium plate RGD polypeptide by self-assembly method.Cell experiments concluded that RGD peptide modified titanium can promote cell adhesion and proliferation,increased alkaline phosphatase activity and promote the formation of calcified nodules,indicating that RGD peptide can enhance osteoblast osteogenic differentiation ability of.RT-qPCR experiment shows that titanium plate fixed RGD polypeptide can upregulate the expression of osteocalcin gene,that promotes osteogenic differentiation into bone cells;expression of osteoprotegerin gene,RGD polypeptide can also inhibit osteoclast activity,strong evidence of osteoblastic RGD polypeptide.