【作者】 张玲；

【导师】 李星逸；

【作者基本信息】 佳木斯大学 ， 材料加工工程， 2009， 硕士

【摘要】 本文采用造孔剂法,利用纯镁粉做造孔剂,高温烧结制得多孔含镁超细晶羟基磷灰石(HA)生物材料。研究了镁粉添加量对多孔含镁超细晶HA孔隙率的影响,及保温时间和烧结温度对多孔含镁超细晶HA力学性能的影响,并初步讨论了多孔含镁超细晶HA的生物活性。采用SEM观察表面形貌,通过原子吸收光谱分析模拟体液中镁离子浓度的变化,利用XRD及TEM分析物相成分、微观形貌及组织结构。采用体外试验法对实验材料进行成骨细胞黏附、生长能力的测定,将多孔含镁超细晶HA植入兔股骨内,研究其骨诱导能力。研究表明,本实验制备的多孔含镁超细晶HA的孔隙率随镁含量的增加而增加,镁含量在5~25wt%之间时,多孔含镁HA的孔隙率在30~70%,当镁含量为20wt%时,多孔含镁HA的孔隙率可达62%以上,且孔隙均匀相互贯通。在本实验的条件下,多孔含镁HA的压缩强度随烧结温度的升高而增加,在1250℃时达到36MPa。在烧结温度一定时,随烧结时间的增加,其压缩强度先增加后减小。加入纯镁粉后的烧结体,其主相仍然是HA相,且多孔含镁HA的晶粒尺明显得到细化,处于亚微米级;镁的加入使得在实验条件下,既保存了多孔材料的生物活性,又克服了纯HA高温烧结过程中晶粒长大的缺点。模拟体液浸泡实验表明,多孔含镁HA的表面及断口处均可形成磷酸钙,说明多孔含镁HA具有较好的形成类骨磷灰石的能力。通过对镁离子浓度的测定表明,随着浸泡时间的延长,镁离子浓度的变化范围始终在25~60ppm之间,在人体正常镁离子的浓度(25~50ppm)范围内,这与人体需要的镁离子的浓度相近的。成骨细胞分别与Mg-HA,MgO-HA,纯HA三种材料复合培养,培养24小时后Mg-HA组细胞黏附率最高为46%,于3天、6天、9天进行四氮唑盐(MTT)细胞增殖、扫描电镜(SEM)取材检测,结果显示,Mg-HA组材料的细胞活性最好。材料在兔体内种植实验研究结果表明,多孔含镁HA材料在体内逐渐降解,并被大量新生骨所取代,无炎症发生,具有优良的成骨性能。材料植入一个月,即有大量新生骨小梁形成。研究表明:多孔含镁HA材料是一种很有发展前途的骨修复支架材料。更多还原

【Abstract】 Porous HA with ultra-fine grain containing Mg was prepared by high-temperature sintering, which Mg had been taken as the hole maker. The effect of the magnesium on the porosity of the porous hydroxyapatite were studied, as well as the effect of the sintering temperature and time on the mechanical properties of the porous hydroxyapatite. The biological activity of porous hydroxyapatite in vitro had been studied. The microstructure and composition of HA were analyzed by TEM, SEM and XRD. The varieties of magnesium ions in SBF were carried out by atomic absorption spectrometry. The biological compatibilities both HA and porous HA had been studied in the paper.The experimental results shows that the porosities of the porous HA increased with the amount of magnesium, and the porosities could be increased more than 62% when the contents of Mg is 20wt%, which were beneficial to the growth of the new bone. The compressive strength and bending strength of the porous HA could be enhanced by in creasing of the sintering temperature and sintering time. The main phase was HA and MgO and the grain size of HA in porous HA was sub-micron when adding pure magnesium into sintering body, which indicated that the Mg were not only to preserve the biological activity of porous material, and also overcome the shortcomings of the grain grow in the course of high-temperature sintering of HA.SBF experiments showed that the surface and fracture of the porous HA could form the calcium phosphate and calcium magnesium phosphate, which illuminated that the porous HA containing magnesium had the ability of forming bone-like apatite. The concentration of magnesium ions were always been in the range between 25 to 50ppm, though with the soaking time longer, which were in the range of the normal human body and in line with the amount of magnesium ions that the body needs .Osteoblasts were trained with Mg-HA materials, MgO-HA materials and pure HA composite materials. The rate of the cell adhesion were to 46% after 24 hours. In 3 days, 6 days, 9 days, the experimental results of the cell proliferation of Tetrazolium salt (MTT) and scanning electron microscopy (SEM) shows that the best of activity of cell of three kinds of materials were that the Mg-HA, then MgO-HA material, and pure HA material was the last.The experimental results of the planting materials in the rabbits show that the porous HA containing magnesium in the body were gradually degraded, and was replaced by a large number of new bone, non-immune inflammation occurred, which had excellent in biocompatibility and osteogenic activity, and a large number of new bone were formed when implanting one month. The porous HA containing magnesium had good ability of inducing bone form and was a promising bone repair scaffolds.更多还原