软硬模板法制备微纳多级结构羟基磷灰石（HA）及其生物活性研究

发布时间：2018-02-02 18:02

本文关键词： 微纳结构模板法羟基磷灰石生物活性　出处：《西南科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：人类骨和牙齿是一类非常重要的生物矿物,主要由有机基质和羟基磷灰石(HA)经过有序组装形成的。HA具有优异的生物相容性和生物活性,因而在生物医学领域具有广泛的应用,并引起了研究者广泛而持久的关注。随着HA研究的深入,具有微纳多级结构的HA材料,由于其特殊的表面结构能够增强材料的吸附性能和促进细胞生长,因而成为目前重点研究内容之一。但是,目前仍然存在许多不足,如对HA微纳多级结构还无法做到精确的控制,HA结晶性不易控制以及HA材料的生物相容性问题等,因此在现有研究的基础上,通过对模板的进一步筛选和优化,从而实现对HA微纳多级结构的精确控制以增强其表面细胞的附着和生长能力具有重要的实践意义。以上述思路为出发点,本课题分别研究了自制的碳酸钙(Ca CO3)微球和改性的关节软骨膜(ACM)等两种不同的硬质和软质模板对HA微纳多级结构的诱导和控制,并在此基础上研究了不同模板所制备HA的生物活性等。主要研究内容和实验结果如下:(1)硬模板法:首先,使用沉淀法在羧甲基纤维素钠作用下制备具有规则形貌的单分散Ca CO3微球,并以此为硬模板,在水热条件下制备单分散且均一的微纳多级结构HA微球。研究了不同的温度和十二烷基苯磺酸钠浓度实现了对HA微球纳米结构单元形貌的影响。同时,基于XRD、FTIR和HRTEM表征结果,提出了在不同温度和不同浓度SDBS的作用下的机理,我们认为是在不同温度或不同浓度SDBS作用下HA晶体的晶面生长情况不同,从而控制HA晶体的形貌。研究结果表明:HA微球表面由HA纳米棒或纳米片组成,平均粒径约为7-8μm,且具有尺寸均一、分散性好、比表面积较大等优点。药物负载和释放实验结果表明,它是一种良好的药物载体材料。进一步的体外细胞实验结果表明,HA微球能够很好的促进人类骨肉瘤细胞(MG-63)的粘附和增殖,具有良好的生物活性,而且由纳米片组成的HA微球与纳米棒组成的HA微球相比,更有利于促进细胞增殖。(2)软模板法:使用改性的ACM作为软模板,在人体模拟体液中(1.5SBF)自组装合成海绵状微纳多级结构HA材料。利用SEM、XRD、FTIR和TEM对其结构和组成进行了表征,结果表明合成的样品为碳酸HA晶体,且由大量的HA纳米片组装成三维互连海绵状结构。根据所制备的样品与松质骨(CB)组成和结构的相似性,比较了它们的密度、孔隙率和比表面积。结果表明,海绵状HA材料除了与CB具有相同的结构和成分外,还具有更高的密度、孔隙率和比表面积。细胞培养实验结果显示,海绵状HA材料能够很好地促进MG-63细胞增殖和生长,具有良好的生物活性。本文的研究结果将为HA微纳多级结构的精确控制和新型微纳多级结构的构建提供方法支撑,为HA纳米级结构单元对其生物活性的影响研究提供有益的借鉴。
[Abstract]:Human bone and teeth are a very important class of biological minerals, mainly composed of organic matrix and hydroxyapatite (HA) through ordered assembly. Ha has excellent biocompatibility and bioactivity. As a result, it has been widely used in the field of biomedicine, and has attracted extensive and lasting attention of researchers. With the development of HA research, HA materials with micro, nano and multilevel structure have been developed. Because its special surface structure can enhance the adsorption performance of the material and promote cell growth, it has become one of the most important research contents. However, there are still many shortcomings. For example, it is not possible to accurately control the crystallinity of HA and the biocompatibility of HA materials, so it is based on the existing research. Through the further screening and optimization of templates, it is of great practical significance to realize the precise control of HA micro-nano multilevel structure to enhance the adhesion and growth ability of HA surface cells. In this paper, the induction and control of HA microstructures by two different hard and soft templates, such as calcium carbonate calcium carbonate microspheres and modified articular chondrocytes ACMs, were studied. On this basis, the biological activity of HA prepared by different templates was studied. The main contents and experimental results are as follows: 1) hard template method: firstly. Monodisperse Ca CO3 microspheres with regular morphology were prepared by precipitation method under the action of sodium carboxymethyl cellulose and used as hard template. Monodisperse and homogenous nano-multistage HA microspheres were prepared under hydrothermal conditions. The effects of different temperatures and sodium 12 alkylbenzene sulfonate concentration on the morphology of HA microspheres were studied. Based on the results of FTIR and HRTEM characterization, the mechanism of SDBS at different temperature and concentration was proposed. We think that the crystal plane growth of HA crystal is different under the action of different temperature or different concentration of SDBS. The results show that the surface of the microspheres is composed of HA nanorods or nanoparticles, the average diameter is about 7-8 渭 m, the size is uniform and the dispersity is good. The results of drug loading and release experiments show that it is a good drug carrier material. Ha microspheres can promote the adhesion and proliferation of human osteosarcoma cells (MG-63), and have good biological activity, and the HA microspheres made up of nanorods are compared with HA microspheres made up of nanorods. Soft template method: modified ACM was used as soft template. The spongy micro-nano multistage structure HA material was synthesized by self-assembly of 1.5SBF in human simulated body fluid. The structure and composition of HA were characterized by SEM-XRDX FTIR and TEM. The results show that the synthesized sample is HA carbonate crystal, and is composed of a large number of HA nanoparticles to form a three-dimensional interconnecting sponge structure. The composition and structure of the prepared sample are similar to that of cancellous bone (CBB). The density, porosity and specific surface area of these materials were compared. The results showed that the spongy HA material had higher density besides the same structure and composition as CB. Porosity and specific surface area. The results of cell culture showed that spongy HA could promote the proliferation and growth of MG-63 cells. The results of this paper will provide the method support for the accurate control of HA micro-nano multilevel structure and the construction of new micro-nano multilevel structure. It provides a useful reference for the study of the effect of HA nanostructure unit on its biological activity.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R318.08

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