氧化锌对纳米羟基磷灰石/壳聚糖复合骨水泥理化性能的影响

Effects of zinc oxide on the physico-chemical properties of n-HA/chitosan cement

质量比为70∶30的n-HA/CS复合材料与适量ZnO粉末的共混物为固相,选用合适的固化液,按照适当的固/液比例进行调和,制备出一种在空气、生理盐水及血液或体液中均可快速固化的新型n-HA/CS复合骨水泥,考查了ZnO含量对该骨水泥理化性能的影响。结果表明:当ZnO与复合材料质量比为1∶8、固化液与固相粉末比例(L/P)为1.2ml/g时,所制备的复合骨水泥抗压强度和固化时间均较佳,能够满足临床操作的需要。ZnO/复合材料质量比分别为1∶8和1∶5的骨水泥在生理盐水中的pH值随浸泡时间的延长而逐渐升高,前者在第20d时pH值维持在7.28左右,而后者在第20d时的pH值接近7.40,均与人体的pH环境相近。当ZnO/复合材料质量比为1∶8时,骨水泥对水的接触角最小,表明其具有良好的润湿性能。ZnO含量越高,骨水泥的吸水率越低,这对于保持骨水泥植入体内后的体积稳定性具有重要价值。SEM观察发现,固化后的骨水泥中含有大量微孔,有利于营养物质的传递及代谢废物的排泄,并利于新生骨组织的长入及爬行替代。

A new type of bone cement which can fast set in air,water,0.9% NaCl solution or blood was prepared by introducing ZnO powder into n-HA/CS composite and choosing appropriate liquid. Study results indicate that,when the mass ratio of ZnO/composite was 1/8 and liquid/powder was 1.2ml/g,the compressive strength and setting time of the cement are both appropriate value. The compressive strength of the cement in 0. 9% NaCl solution increases with the immersing time,and reaches the maximum after 72h,then declines due to the degradation of chitosan. The pH of the cement immersing in 0. 9% NaCl solution for 20 days was close to the pH of human body fluid. In addition,the cement shows very small water contact angle,indicating that the cement has high wettability,and the addition of ZnO improves the volume stability of the cement. SEM observation illuminates that large numbers of micro-pores exwast in the setting cement, which was desirable for the in- growth or creeping substitute of bone twassue.