构建水凝胶电纺纤维支架实现高糖氧化应激微环境下骨修复的机制研究

Diabetic secondary osteoporosis and its fragile fractures have attracted more attention. Its high degree of ischemia and metabolic disorders of the microenvironment lead to the reduction of nutrients, resulting in a large number of inflammatory factors and oxygen free radicals, seriously weaken the survival and differentiation of osteogenesis-relative cells. Based on our previous study, we put forward the viewpoint of promoting cells' anti-apoptotic and inducing early vascularization under the condition of high glucose oxidative stress may accelerate the process of bone repair. We choose desferrioxamine (DFO) as the intervention drug, and by using new photocrosslinked hydrogel electrostatic spinning and liposome encapsulation technology, we produce structural bionic composite scaffold materials with timely and efficient controlled drug release for the key step of vascular invasion in the process of bone reconstruction and effectively restrain the oxygen free radicals. Through a series of molecular biology, histology, iconography, bone histomophormetry and other experimental techniques in vivo and in vitro, we in-depth study of how to stimulate anti-apoptotic, angiogenesis and osteogenesisv"coupling" mechanism in high glucose microenvironment. When acquiring bone microenvironment mimic, effective anti-apoptosis and easy to vascularized biological scaffold, we reveal the bone regeneration process involved in the process of cell molecular biological mechanism and its key role in the treatment of diabetic osteoporosis and provide new ideas.

由糖尿病引起的继发性骨质疏松及其脆性骨折备受关注。其高度缺血、代谢紊乱的微环境导致营养物质的减少、产生大量炎症因子和氧自由基，严重削弱了成骨相关细胞的存活及分化能力。基于课题组以往研究成果，我们提出高糖氧化应激条件下实现骨缺损区域细胞抗凋亡并适时诱导血管新生有可能加速骨修复进程的观点。选择去铁胺作为干预药物，利用光交联水凝胶静电纺丝及脂质体包裹技术，构建在有效抑制氧自由基前提下针对骨修复进程中血管侵入的关键环节高效控释药物、结构仿生的骨修复复合支架材料。通过体内、外一系列分子生物学、组织学、影像学、骨组织形态计量学等实验技术手段，深入探讨如何在高糖微环境中，激发抗凋亡与成骨、成血管“偶联”机制。在获得可模拟骨内微环境、有效抗凋亡且易于血管化生物支架的同时，揭示骨再生过程中的细胞分子生物学机制及其关键作用环节或靶点，为治疗糖尿病性骨质疏松提供新的思路。

由糖尿病引起的继发性骨质疏松及其脆性骨折备受关注。其高度缺血、代谢紊乱的微环境导致营养物质的减少、产生大量炎症因子和氧自由基，严重削弱了成骨相关细胞的存活及分化能力。基于课题组以往研究成果，我们提出高糖氧化应激条件下实现骨缺损区域细胞抗凋亡并适时诱导血管新生有可能加速骨修复进程。随后，我们将去铁胺药物装载于脂质体内，利用光交联水凝胶静电纺丝技术成功构建了生物支架材料。通过体外实验检测支架材料理化特性，验证了该支架具有良好的生物相容性，具备一定力学强度且药物释放高效稳定。同时，该载药支架在体外高糖培养基中，能够有效激活BMSCs内的线粒体通路发挥抗氧化应激，从而减少凋亡，并进一步通过激活HIF-1信号通路，上调成血管及成骨相关基因和蛋白的表达。在体内实验中，我们构建了1型糖尿病小鼠的股骨远端骨缺损模型，将载药支架包裹于骨缺损表面，发现其能有效加速缺损部位的骨愈合进程。因此，在本课题中，我们获得了可模拟骨内微环境、有效抗凋亡且易于血管化生物支架，并进一步揭示了骨再生过程中的细胞分子生物学机制及其关键作用环节或靶点，为治疗糖尿病性骨质疏松提供新的思路。