柚皮苷对骨质疏松状态下颅颌面骨缺损修复的机理研究

The cranio-maxillo-facial bone defect healing of osteoporosis patients remains a major challenge in dental medicine.The prevalence rate of osteoporosis in China is expected to be 13.3% in 2050. The conventional single cell-type culture study showed naringin (an active constituent of Chinese traditional medicine) could stimulate the proliferation and differentiation of osteoblasts and decrease osteoclast formation. However, osteoporosis is thought to be caused by the imbalance of osteobalsts and osteoclasts. The rate of bone resorption by osteoclasts is higher than the rate of new bone being deposited by osteoblasts. Single cell type study can not reveal the interaction between the two type of cells. In our previous work, the mouse calvarial organ culture model was established by Micro-CT technique. Bone organ cultures have an advantage over isolated cell systems in that they preserve the interrelationships between the different cell types (osteoblasts, osteoclasts and osteocytes) in the bone, and the relationship between these cells and bone matrix. Therefore, bone organ culture method is proposed to evaluate the effect of naringin on the co-existence of osteoblasts and osteoclasts from the molecular, cellular, and tissue level. The critical size defect model of osteoporosis will be established and used to evaluate the bone healing potential of composite material. This project will provide very important theoretical base which is invaluably significant.

骨质疏松患者合并颅颌面骨缺损修复系口腔临床医学亟待解决的世界难题之一。预计到2050年我国骨质疏松症的患病率为13.2%。既往单一种类细胞实验证明中药活性物质柚皮苷具有促进成骨细胞增殖和分化以及抑制破骨细胞形成的作用。然而，骨质疏松是成骨和破骨细胞失衡，破骨量大于成骨量所致，单一种类细胞实验不能揭示两种细胞之间的相互作用。我们的前期工作基于显微CT技术建立了小鼠颅顶骨器官培养模型。与单一种类细胞实验相比，该模型保留了各种相互关联的细胞（成骨细胞、破骨细胞和骨细胞），以及细胞和细胞外基质的天然关系。因此，项目组拟用该模型从分子、细胞和组织水平上分析柚皮苷对共存的成骨细胞和破骨细胞的作用机理，率先建立骨质疏松状态下的颅顶骨临界缺损动物模型并用来评估含柚皮苷复合材料的骨修复能力。这将为柚皮苷作为抗骨质疏松药物和骨修复材料的开发提供理论基础，具有不可估量的研究价值。

骨质疏松症患者骨缺损的愈合也已成为全世界临床医生面临的挑战。柚皮苷是中药骨碎补的主要活性成分。本项目研究发现骨碎补主要活性物质柚皮苷能促进成骨细胞 OPG 基因 mRNA 表达，还可以影响鼠颅顶骨中TRAP阳性细胞数量及其功能。此外，我们率先建立了老年性骨质疏松模型小鼠的颅骨临界缺损模型。我们首次将中药骨碎补的主要活性物质柚皮苷与静电纺纳米纤维技术相结合，制备出控释柚皮苷的纳米纤维膜，并创新性地加入双亲嵌段共聚物PEG-b-PCL，极大的改善了膜的亲水性、药物释放行为和材料降解性。经细胞实验和骨器官培养实验发现该膜具有增强成骨细胞的功能和减少破骨细胞形成的性质。经体内实验发现该膜对骨质疏松状态下的临界缺损有一定的修复能力。这将为柚皮苷作为抗骨质疏松药物和骨修复材料的开发奠定了基础。