新型壳-芯结构载γ-Fe2O3构建磁性纳米复合支架促进骨缺损修复的研究

Repair and reconstruction of bone defects is a challenge in dentistry. Tissue engineering is an effective approach to solve the problems resulting from bone insufficiency or defects. However, problems still exist in the application of bioactive factors in the composites for their short effective time, immunogenicity and uncertain security, which are urgent to be solved. Our project introduces γ-Fe2O3, a magnetic particle with high biological safety (approved by CFDA) and osteogenic potential, into the field of bone regeneration in stomotology. We intend to fabricate a novel core-shell nanocomposite scaffold with sustained release of γ-Fe2O3 to achieve a synergistic effect in bone regeneration through interaction between γ-Fe2O3 and external magnetic field. The scaffold makes it possible to fully exert the advantages of non-invasive physical therapy of magnetic effect, regulate the differentiation and behavior of mesenchymal stem cells, and in turn to promote bone regeneration. In this study, the strategy of controlled release of magnetic nanoparticles and their magnetic effect matching with bone defect repair rate was adopted. The effects of magnetic nanocomposite scaffolds on bone regeneration will be systematically evaluated by in vitro and in vivo experiments. In consequence, the interaction of magnetic nanoparticles, external magnetic field and bone regeneration will be revealed, which is able to provide a new therapy to repair clinical bone defect. The exploration in the long-term delivery of magnetic nanocomposite scaffolds with sustained release will also make sense for the biological material carrier system.

骨缺损的修复与重建是口腔临床中的难点之一。组织工程是解决骨缺损/骨量不足的有效途径，但复合材料中的功能性因子尚存在作用时间短、免疫原性、安全性不确定等诸多问题，是亟需解决的难点。本项目将生物安全性高（经CFDA批准）、有成骨潜能的γ-Fe2O3引入口腔骨组织再生领域，利用具有缓释功能的新型壳-芯结构构建磁性纳米复合支架，通过γ-Fe2O3与外加磁场的相互响应，形成协同扩增效应，发挥磁效应具备非入侵式物理治疗方式的优势，调控间充质干细胞的分化和行为，最终促进骨修复。本研究采用磁性纳米粒子控释与磁效应两者与骨缺损修复速率相适配的策略，从细胞水平及组织器官水平出发，系统评价磁性纳米复合支架促进骨修复的效果，最终揭示磁性纳米粒子、外加磁场与骨组织修复的交互机制；为临床提供一种修复骨缺损的新的治疗方式，其探索的磁性纳米复合支架长期递送功能性粒子的缓释途径对生物材料载体系统同样具有参考与借鉴价值。

骨缺损的修复与重建是口腔临床中的难点之一。组织工程是解决骨缺损/骨量不足的有效途径，但复合材料中的功能性因子尚存在作用时间短、免疫原性、安全性不确定等诸多问题， 是亟需解决的难点。本项目将生物安全性高(经CFDA批准)、有成骨潜能的γ-Fe2O3引入口腔骨组织再生领域，利用具有缓释功能的新型壳-芯结构构建磁性纳米复合支架，将多孔纤维支架的骨引导性与磁性纳米粒子的骨诱导性结合，实现磁性纳米粒子的均匀携载和长期释放，改善支架的机械学性能，赋予支架超顺磁性；通过γ-Fe2O3 与外加磁场的相互响应，形成协同扩增效应，发挥磁效应具备非入侵式物理治疗方式的优势，调控间充质干细胞的分化和行为。本研究从细胞水平及组织器官水平出发，系统评价磁性纳米复合支架促进骨修复的效果，探索磁性纳米粒子、外加磁场与骨组织修复的交互机制，为临床骨缺损修复和功能性因子的长期递送提供新策略与理论基础。