Abstract:

Abstract:Objective To explore the changes of PH values of N,[KG-3]O-CMC/β-TCP compositive materials with different mass fractions in simulated body fluids (SBF) and their influence in the growth of MG63 cells,and to illustrate their mechanisms,and to provide reference for the further research on the bone repair materials.Methods The N,[KG-3]O-CMC/β-TCP with mass fractions of 2/1,1/1 and 1/2 were used as experimental groups,and the collagen nano calcium phosphate bone repair material as control group.The materials with  different mass fractions  were immersed in SBF and the pH values were measured by  pH meter after soaking for 7,14,21 and 28d,respectively.The MG63 cells with the concentration of 1×105mL-1 were inoculated and co-cultured in experimental and control groups,the adhesion and morphological changes of MG63 cells in each group were observed by scanning electron microscope and the cell proliferation was detected by MTT method after co-culturing for 2,4 and 6 d.Results The pH values were 6.70－7.25 in N,[KG-3]O-CMC/β-TCP (1/2) group and N,[KG-3]O-CMC/β-TCP(2/1) groups   and the pH value  in 　N,[KG-3]O-CMC/β-TCP (1/1) group was basically 7.15. The cells in N,O-CMC/β-TCP  (2/1) group formed owe full,spreading face small and less secretion,but the cells in N,[KG-3]O-CMC/β-TCP 1/2 and 1/1 groups formed in full,pseudopodia interconnection,widely spreading and more secretions under electron microscope. The proliferation rate of the cells in N,[KG-3]O-CMC/β-TCP with (1/1) and N,[KG-3]O-CMC/β-TCP(2/1) groups had no statistical differen ce compared with control group (P>0.05),but there was significant difference between control group and N,[KG-3]O-CMC/β-TCP (1/2) group (P<0.05). Conclusion The changes of pH values of N,[KG-3]O-CMC/β-TCP materials  with different mass fractions in SBF are small and the pH values are neutral;the order of the  mass fraction of  N,[KG-3]O-CMC/β-TCP to promote the growth of MG63 cells is 1/1,2/1,and 1/2.

Key words: N,[KG-3]O-carboxymethyl chitosan, &beta, -tricalcium phosphate, simulated body fluid, methyl thiazoly tetrazolium