巨噬细胞是骨修复材料植入体内后调控炎症、免疫和异物反应的关键介质，植入材料的长期功能行使很大程度上决定于巨噬细胞的M1/M2极化状态和相对比例，其动态平衡已成为决定骨修复成功与否的关键所在，而现有的基于材料本身的优化设计或通过生物分子的控制释放尚无法真正实现其动态平衡调控。本项目旨在构建一类超顺磁性复合支架材料，通过在外部磁场协同作用、以及正常生理和典型病理（骨质疏松、骨肿瘤切除等）情况下，深入揭示外部刺激信号、材料的基本物理化学性质等对巨噬细胞极化时序性影响的相关性及其规律，探索M1/M2极化状态和比例的动态调控与骨缺损免疫修复的关系和作用机理，研究如何提高促进骨缺损修复效能的技术和方法，以期获得一系列具有我国自主知识产权的新型磁性骨组织工程支架材料，为促进磁纳米材料在生物医学领域的应用，特别是为骨相关疾病的临床治疗及骨组织工程支架材料的设计提供思路和理论支撑。

Macrophages are the key mediators to regulate inflammation, immunity and foreign body reaction after implantation of bone repair materials. The long-term function of implanted materials depends largely on the M1/M2 polarization state and proportion of macrophages. The dynamic balance of macrophages has become the key factor to determine the success of bone repair. That the existing optimization design based on the nature of materials or/with drug controlled release is impossible to achieve its dynamic balance control. The aim of this project is to construct superparamagnetic composite scaffolds. Under the synergistic effect of external magnetic field, normal physiology and typical pathology (osteoporosis, bone tumor resection, etc.), the correlation and regularity of external stimulus signals and basic physicochemical properties of materials on the timing of macrophage polarization are deeply revealed, and the dynamics of M1/M2 polarization state and proportion are explored. To regulate the relationship and mechanism between bone defect immune repair and to study the techniques and methods to improve the efficiency of bone defect repair, in order to obtain a series of new magnetic bone tissue engineering scaffolds with independent intellectual property rights in China, and to promote the application of magnetic nanomaterials in biomedical field, especially for the clinical treatment of bone-related diseases and bone tissue engineering scaffolds. The design provides ideas and theoretical support.