Study On The Osteogenic Properties Of The Multiwalled Carbon Nanotubes/Chitosan Composite Containing Zinc

Objective:To explore whether zinc ions on the multiwalled carbon nanotubes/chitosan composite containing zinc ion can promote proliferation and differentiation of osteoblast,and the appropriate concentration of zinc ion on the composite materials.Methods:The multiwalled carbon nanotubes/chitosan composites with different content of zinc ions were prepared,and observed by scanning electron microscope.Thereinto,0.2% zinc content of the composite is low-zinc group,1% zinc content of the composite is medium-zinc group,2.5% zinc content of the composite is high-zinc group,the composite without zinc is the control group.The MC3T3-E1 cells were seeded on the surface of the four kinds composites.By using MTT methods、micronutrients enzymes standard method、ELISA 、 laser scanning confocal microscope,cell proliferation 、 alkaline phosphatase activity、level of osteocalcin and osteoprotegerin、cell morphology were detected.Results:Scanning electron microscope picture shows that the composite material has a large number of pore structure.MTT tests of 24 h,48h,72 h showed that the proliferation of cells in the medium-zinc group was higher than that in the control group(P < 0.05),and the proliferation of the low-zinc group was not significantly difference with control group(P >0.05),and the proliferation of the high-zinc group was less than that of the control group(P< 0.05).Alkaline phosphatase activity tests of 24 h,48h,72 h showed that the alkalinephosphatase activity of cells in the medium-zinc group was higher than that in the control group(P < 0.05),and the low-zinc group was not significantly difference with control group(P > 0.05),and the high-zinc group was less than that of the control group(P < 0.05).Osteocalcin level tests of 48 h showed that the osteocalcin level of cells in the medium-zinc group was higher than that in the control group(P < 0.05),and the low-zinc group was not significantly difference with control group(P > 0.05),and the high-zinc group was less than that of the control group(P < 0.05).Osteoprotegerin level tests of 48 h showed that the osteocalcin level of cells in the medium-zinc group was higher than that in the control group(P < 0.05),and the low-zinc group was not significantly difference with control group(P > 0.05),and the high-zinc group was less than that of the control group(P < 0.05).By laser scanning confocal microscopy,we observed that the expansion extent of medium-zinc cells were the best,and the expansion extent of low-zinc cells were worse than the medium-zinc cells,and there was not obvious difference between low-zinc group and control group.Conclusion:Comparing with multiwalled carbon nanotubes/chitosan composite without zinc,low-zinc-group composites did not have the ability for improving the proliferation and differentiation of the MC3T3-E1 cells,and the proliferation and differentiation of MC3T3-E1 cells were more favorable on the middle-zinc-group composites,and high-zinc-group composites inhibited the proliferation and differentiation of MC3T3-E1 cells.