基于电磁响应引发生物学效应的羟基磷灰石基纳米复合材料

Based on the theroies of bone electrophysiology and positive response of electromagnetic stimulating bone growth, carbon nanotube (CNT)/grapheme (G)/hydroxyapatite (HA) nanocomposites with sensitive response to the electromagnetic stimulation will be fabricated. The contents of this project include as following. Firstly, the magnetic G sheets with uniformly deposited magnetic particles were prepared by hydrothermal method. Secondly, combined with the method of chemical vapor deposition, the main skeleton was built by CNT arrays in-situ growing on G sheet. Finally, HA nanoparticles were evenly filled in the CNT/G composite scaffold by the strategies of mineral deposition or electrostatic self-assemble process. Therefore, CNT/G/HA nanocomposites with electromagnetic response were obtained. The mechanism of the nanocomposites regulating adherence and release of bioactive factors, cell metabolism and promoting new bone formation under the applied electromagnetic stimulation will be deeply researched. When these nanocomposites were applied in the clinic fields, the bioactive factors in vivo can be actively adsorbed and loaded on these nanocomposites, and sequentially released to surrounding tissue under the applied electromagnetic stimulation. This process can be opened and closed repeatedly according to the clinical demands. Under the electromagnetic stimulation, the bioactive factors in vivo can be purposefully guided to adhere on this bone plant according to the clinical needs, which is similar to the process of body-derived growth factor production and benefit the reconstruction of bone tissue and vascularization. This research on CNT/G/HA nanocompoistes with electromagnetic response provides experimental data and theoretical background in certain extent for the research on regulating and controlling bone tissue growth under the true physiological electromagnetic environment.

本项目基于骨电生理和骨组织对电磁刺激有正响应的原理，拟将具有优良导电性能的石墨烯（G）和碳纳米管（CNT）用于增强生物活性羟基磷灰石（HA），结合纳米磁性粒子在G片层的均匀沉积，构建具有电磁响应性的CNT/G/HA纳米复合材料。研究内容包括：通过热液法在片层G上均匀沉积一层纳米磁性粒子，利用化学气相沉积法在G上生长CNT阵列，构建“磁性片层G-管状CNT”的CNT/G主体骨架；通过矿化沉积或自组装等技术将纳米HA填充于主体骨架中，获得具有电磁响应性的CNT/G/HA纳米复合材料。深入研究在电磁刺激下材料将电磁作用最终转化为生物化学信号，调控骨相关细胞的代谢，以及体内生物活性因子的富集与释放，促进新骨生成的作用机制。这种可按“需”进行“开关式”主动引导细胞和活性因子正常代谢活动的生物材料，能很好模拟体内内源性骨重建的过程，为真实生理条件下骨组织生长的调控研究提供一定的科学依据。

本项目基于骨电生理和骨组织对电磁刺激有正响应的原理，将具有优良导电性能的石墨烯（G）和碳纳米管（CNT）用于增强生物活性羟基磷灰石（HA），再结合纳米Fe3O 4粒子良好的磁性能，分别采用两种方法来构建具有电磁响应性的CNT/G/HA纳米复合材料。第一种方法利用化学气相沉积法在磁性G上生长CNT阵列，构建“磁性片层G-管状CNT”的CNT/G主体骨架，然后通过仿生矿化将纳米HA沉积于主体骨架中，获得具有电磁响应性的CNT/G/HA纳米复合材料。第二种方法采用静电自组装技术将片层G和管状CNT相复合，搭建起具有良好“片层G-管状CNT”的CNT/G主体骨架，然后利用一步原位共沉积法和两步静电自组装法将磁性HA均匀地复合在CNT/G主体骨架上。利用体外细胞共培养试验深入研究在外加电磁刺激下该电磁响应性材料将电磁作用转化为生物化学信号，调控骨细胞代谢以及体内生物活性因子的表达，揭示出电磁作用下电磁响应性HA复合材料促进新骨生成的分子作用机制。这种可按“需”进行“开关式”主动引导细胞和活性因子正常代谢活动的生物材料，为新一代人工骨植入体的研究提供一定的科学依据。