激光熔覆钙磷涂层中的稀土可控析出及其生物学性能

发布时间：2018-04-15 13:54

本文选题：激光熔覆 + 生物陶瓷涂层　；参考：《贵州大学》2015年硕士论文

【摘要】：本文从材料表面改性入手,结合稀土对骨代谢的影响来抑制破骨细胞的活性,为治疗磨屑病提供相关借鉴。采用激光熔覆技术、梯度设计思想和加入稀土氧化物La2O3的方法,在TC4合金上制备了一层含磷酸钙生物复合陶瓷涂层,利用OM、显微硬度计、SEM、XRD、SBF、ICP-AES、MTT、TRAP染色等方法,对涂层的结合界面、显微硬度、组织结构、微观形貌、生物活性以及对破骨细胞活性抑制等方面进行研究,结果表明:(1)在不同钙磷比涂层中,稀土的加入都能够很好的改善涂层与基材的结合,使涂层之间形成良好的冶金结合。(2)在不同钙磷比条件下,不同稀土含量对涂层的显微硬度、物相都有影响。生物陶瓷涂层主要是由CaTiO3、TiO2、CaO、β-TCP和HA等物相组成的复杂相涂层。Ca:P=1.4的涂层生成的生物活性相β-TCP和HA要比1.5的多。而当稀土含量为0.4 wt.%时,涂层中β-TCP和HA的衍射峰值最大,说明涂层具有较好的生物活性。(3)对涂层表面进行微观形貌观察与能谱分析发现,涂层表面为典型黑亮陶瓷状,局部有小型孔洞,表面并无明显裂纹产生。涂层中主要含有O、P、Ca、Ti等元素,其中钙磷原子比为1.61,与磷酸钙中HA和TCP的钙磷原子比相近。(4)在模拟体液中,稀土的加入能够改善陶瓷涂层表面类骨磷灰石数量与尺寸大小。Ca:P=1.4时比Ca:P=1.5的涂层在模拟体液中形成的类骨磷灰石要多;Ca:P=1.4,稀土氧化物添加量为0.4wt.%~0.6wt.%时,涂层在模拟体液中浸泡14天后,具有较好的性能。涂层经浸泡后形成均匀分布,大小一致,无裂纹产生的涂层表面。(5)浸泡在模拟体液中的涂层质量随着浸泡时间的增加,而逐渐减少。涂层在模拟体液中浸泡28天,涂层的降解率为0.2126%。随着浸泡时间的变化,钙离子在模拟体液中的浓度是一个动态的变化过程。模拟体液中稀土离子浓度随浸泡时间增加逐渐增大。(6)不同稀土氧化物含量涂层的破骨前体细胞活性不同,表现出随时间增加,活性减弱的趋势。在6天后,细胞活性最低。说明含稀土氧化物的涂层对细胞活性存在抑制作用。(7)细胞在不同稀土含量的涂层中培养12天后,用TRAP染色和甲基绿复染色后发现,不同稀土含量的染色效果不同,涂层表面形成陷窝数量不同。稀土氧化物含量为0.4 wt.%时,陷窝数少于其他组,说明此时稀土对RANKL诱导破骨前体细胞形成破骨细胞有抑制作用。
[Abstract]:In this paper, the surface modification of materials and the effect of rare earth on bone metabolism were introduced to inhibit the activity of osteoclasts and provide reference for the treatment of debris disease.A layer of calcium phosphate bioceramics coating was prepared on TC4 alloy by laser cladding technology, gradient design method and adding rare earth oxide La2O3. The interface of the coating was studied by means of OM, microhardness tester, SBFICP-AESMA MTTTRAP staining, etc.The microhardness, microstructure, morphology, biological activity and inhibition of osteoclast activity were studied. The results showed that the addition of rare earth elements in the coatings with different Ca / P ratios could improve the bonding between the coating and the substrate.Under different Ca / P ratios, different rare earth contents have an effect on the microhardness and phase of the coatings.The bioceramic coating is composed of CaTiO3TiO2CaO, 尾 -TCP and HA. The bioactive phase 尾 -TCP and HA are more than 1.5 by the coating of CaTiO3TiO2CaO, 尾 -TCP and HA.When the content of rare earth is 0.4 wt.%, the diffraction peak of 尾 -TCP and HA in the coating is the largest, which indicates that the coating has good bioactivity.There are small holes and no obvious cracks on the surface.The coating mainly contains elements such as O _ (P _ (P)) _ (Ca ~ (2 +)) Ti, in which the ratio of Ca ~ (2 +) to P ~ (2 +) is 1.61, which is similar to that of HA in calcium phosphate and that of TCP in simulated body fluid.The addition of rare earth can improve the amount and size of bone-like apatite on ceramic coating surface. The amount and size of bone-like apatite on ceramic coating surface is more than that of bone-like apatite formed in simulated body fluid by Ca:P=1.5 coating. When the amount of rare-earth oxide is 0.4wt.%, the coating is immersed in simulated body fluid for 14 days.It has good performance.After soaking, the coating was uniformly distributed and uniform in size, and the coating surface without cracks was gradually reduced with the increase of immersion time.When the coating was immersed in simulated body fluid for 28 days, the degradation rate of the coating was 0.2126.With the change of immersion time, the concentration of calcium ion in simulated body fluid is a dynamic process.The concentration of rare-earth ions in simulated body fluid increased gradually with the increase of soaking time. The activity of osteoclast precursor cells with different rare-earth oxide content coatings was different and showed a tendency of decreasing with time.After 6 days, the cell activity was the lowest.The results showed that the coating containing rare earth oxide had inhibitory effect on cell activity. After 12 days of culture in the coating with different rare earth content, TRAP staining and methyl green co-staining showed that the dyeing effect of different rare earth content was different.The number of pits formed on the coating surface is different.When the content of rare earth oxide was 0.4 wt.%, the number of lacunae was less than that of other groups, which indicated that rare earth could inhibit the formation of osteoclasts induced by RANKL.
【学位授予单位】：贵州大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG174.4

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