聚吡咯纳米线/类骨磷灰石图案化复合材料的制备及其与成骨细胞相互作用研究

The application of electrically conductive polypyrrole (PPy) has been a focus in the field of biomedical science over the past dacades. As a bioactive coating material of bone implants, PPy could response to the electrical stimulation, which has caused great interest among researchers. It has been confirmed that PPy could regulate the cell adhesion, spreading and proliferation, and further improve the differentiation of osteoblastic cells under the external electrical stimulation. So PPy was expected to be an ideal stimuli-responsive coatings of bone implants. But unfortunately, PPy has low bioactivity.Under such backgound, the motivation of the present project is to prepare a PPy/apatite composite in order to introduce the good bioactivtiy of apatite to the final composite. It's hoped that such a composite can retain both the advantages of PPy and the high bioactivity of apatite, making it possible for the futher application in the field of bone implant materials. Furthermore, recent studies have confirmed that the topological structure of material surface has a remarkable effect on cell's behaviors and physiological processes. Thus, proper design and preparing of the material surface could control a series of events of cells, such as growth, development, proliferation and differentiation. In addition, the rapid development of MEMs technoloy makes it possible to built micro-patterning sufaces. For these reasons, a micropatterned PPy/apatite composite will be developed in the present project by MEMs technology. The interaction between the micropatterned PPy/apatite composite and the osteoblasts will be investigated and the bioactivity of the PPy/apatite composite will also be studied. The main works are as follows: (1) Preparing and characterizing of the micropatterned PPy/apatite composite and analyzing its bioactivity;(2) Investigating the effect of the micropatterned PPy/apatite composite on adhesion, proliferation and biofunction of the MC3T3-E1 cells.It is expected that the micropatterned PPy/apatite may be employed as a potential implantable biocative coating for clinical applications.

材料表面的拓扑结构和外力场因素（如电刺激等）能对细胞的多种行为及生理功能产生显著影响。因此，研究经适当设计加工后的材料表面在外力场作用下对细胞的生长、发育、增殖以及功能分化等一系列事件的影响，对于制备高性能生物材料具有重要的理论和现实意义。本课题拟采用微机电加工技术构建导电高分子聚吡咯纳米线/类骨磷灰石复合图案，将材料表面的拓扑结构与电刺激相结合，系统考察图案化后的复合材料与成骨细胞之间的相互作用及作用机制，并进一步围绕其生物活性展开深入研究。预期通过本课题的实施，将获得一种具有高生物活性，并能在微纳米层次上精确有效调控成骨细胞生长的骨移植材料表面活性涂层，进而深化导电高分子纳米线这一具有优良刺激响应性能的功能材料在骨移植材料及其相关领域的应用，为开发综合性能更加优异的生物医学新产品提供重要、翔实的理论和实验依据。

将聚吡咯纳（PPy）米线与类骨磷灰石(HA)共同图案化，不仅可以将高生物活性引入所获得的复合材料，而且可以得到一种更加合理的拓扑结构，因而可望展现出比普通聚吡咯纳米线更强的促成骨细胞生长能力的活性层，同时还有助于在更深层次上系统理解材料表面的微纳米结构对于细胞的精确调控和引导作用。这样的一些综合效果，是两种材料简单复合时所不能达到的。因此本课题采用微机电加工技术成功制备金基底材料，且在基底之上形成不同形状的聚吡咯纳米线/类骨磷灰石图案化复合材料，构建聚吡咯纳米线/类骨磷灰石复合图案，将材料表面的拓扑结构与电刺激相结合，系统考察图案化后的复合材料与成骨细胞之间的相互作用及作用机制，最终获得图案规整的、高质量的图案化聚吡咯纳米线/类骨磷灰石复合材料并研究电刺激与非电刺激下聚吡咯纳米线图案化材料及其复合类骨磷灰石后与成骨细胞之间的相互作用。研究表明HA及聚吡咯均能够促进细胞的粘附、增值，早期矿化成骨。当聚吡咯与HA复合之后，这种促进作用更加明显。故所合成的PPy/HA纳米复合材料可用于成骨细胞的培养与研究。. 通过本项目的研究，获得了一种生物活性高，并且能在微纳米层次上更加精确有效调控成骨细胞生长的骨移植材料表面活性涂层，进而深化了聚吡咯纳米线这一具有优良刺激响应性能的功能材料在骨移植材料及其相关领域的应用。即拓展了导电高分子纳米材料在生物医学领域的应用范围，又为开发综合性能更加优异的生物医学新产品提供了重要、详实的理论和实验依据。