不同质量分数N,O-CMC/β-TCP复合材料在模拟体液降解中的pH值变化及其对MG_(63)细胞生长的影响

Changes of pH values of N,O-CMC/β-TCP with different mass fractions in simulated body fluid degradation and their influence in growth of MG_(63) cells

目的：探讨不同质量分数N,O-羧甲基壳聚糖/β-磷酸三钙（N,O-CMC/β-TCP）复合材料在模拟体液（SBF）中的pH值变化及其对成骨样细胞（MG63细胞）生长的影响,并阐明其机制,为骨修复材料的进一步研发提供参考。方法：以质量分数为2/1、1/1和1/2的N,O-CMC/β-TCP作为实验组[分别为N,O-CMC/β-TCP（2/1）组、N,O-CMC/β-TCP（1/1）组和N,O-CMC/β-TCP（1/2）组）],纳米磷酸钙胶原基骨修复材料作对照组;将不同质量分数材料浸泡在SBF中,分别在浸泡的第7、14、21和28天用pH计测量SBF的pH值。MG63细胞以1×10^5 mL^-1密度分别接种于实验组和对照组材料上,并置于培养板中共培养,在培养的第2、4和6天用扫描电镜观察MG63细胞在各组材料上的黏附和形态变化,采用MTT法检测细胞增殖情况。结果：N,O-CMC/β-TCP（1/2）组和N,O-CMC/β-TCP（2/1）组SBF的pH值在6.70-7.25范围波动,N,O-CMC/β-TCP（1/1）组SBF的pH值基本稳定于7.15。扫描电镜观察,N,O-CMC/β-TCP（2/1）组中的细胞形态欠饱满,铺展面小且分泌物少;N,O-CMC/β-TCP（1/1）组和N,O-CMC/β-TCP（1/2）组中细胞形态饱满,伪足相互连通,铺展面广且分泌物多。与对照组比较,N,O-CMC/β-TCP（1/1）组和N,O-CMC/β-TCP（2/1）组细胞相对增殖率差异无统计学意义（P〉0.05）,而N,O-CMC/β-TCP（1/2）组细胞相对增殖率降低（P〈0.05）。结论：不同质量分数N,O-CMC/β-TCP材料在SBF中的pH值变化较小,基本处于中性;促进MG63细胞生长的N,O-CMC/β-TCP质量分数按作用大小依次为1/1、2/1及1/2。

Objective To explore the changes of PH values of N,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,O-CMC/β-TCP with mass fractions of 2/1,1/1and 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 1×10^5 mL-1 were inoculated and co-cultured in experimental and control groups,the adhesion and morphological changes of MG63cells in each group were observed by scanning electron microscope and the cell proliferation was detected by MTT method after co-culturing for 2,4and 6d.Results The pH values were 6.70-7.25 in N,O-CMC/β-TCP（1/2）group and N,O-CMC/β-TCP（2/1）groups and the pH value in N,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,O-CMC/β-TCP1/2 and 1/1groups formed in full,pseudopodia interconnection,widely spreading and more secretions under electron microscope.The proliferation rate of the cells in N,O-CMC/β-TCP with（1/1）and N,O-CMC/β-TCP（2/1）groups had no statistical difference compared with control group（P〉0.05）,but there was significant difference between control group and N,O-CMC/β-TCP（1/2）group（P〈0.05）.Conclusion The changes of pH values of N,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,O-CMC/β-TCP to promote the growth of MG63 cells is 1/1,2/1,and 1/2.