Mir-214在幼龄小型猪颅骨缺损模型新生骨形成过程中的作用及机制研究

Children cranial defects are common in clinic, autologous bone repair is an ideal choice, but due to low bone mass limits the clinical application, the research and development with regenerative ability of artificial bone has been becoming the current research focus. Recent studies have found that through the corresponding target genes to promote or inhibit bone differentiation, mir - 214 plays an important role in the process in of bone formation and degradation. mir - 214 can regulate the expression of OCN and ALP, its also have close relationship with the formation of blood vessels; at the same time our previous studies have found that in the new bone the expression of OCN and ALP was lower than those of normal skull in young miniature pig skull defect model, new bone structure is not fully mature, irregular bone trabecular structure, bone mass, the weak biomechanical properties. Integrating existing research results, we hypothesize that: mir - 214 May be plays a certain role in the formation of new bone, through the regulation of mir - 214 can enhance regulating factor expression, such as,OCN, ALP, promotes the formation of new bone and reconstruction. This study will focus on detection of mir - 214 in the new bone expression, the influence of antagonists and agonists to the expression of mir - 214, the relationship between different expression level of the mir - 214 and new bone osteogenesis, explore the role and mechanism of mir - 214 in the process of young miniature pig new skull bone formation, provide a new mentality for the research of bone regeneration.

儿童颅骨缺损在临床上比较常见，自体骨修复是理想的选择，但是由于骨量少限制了临床运用，致使研发具有再生能力的人工骨成为目前的研究热点。新近研究发现，mir-214在骨形成与降解过程中起着重要的作用，其通过影响相应的靶基因来促进或抑制骨分化作用。mir-214可以调控OCN和ALP等的表达，此外其还与血管的生成有密切的关系；同时我们的前期研究发现在幼龄小型猪颅骨缺损模型新生骨中OCN和ALP的表达较中较正常颅骨低，新生骨结构尚未完全成熟，骨小梁结构不规律，骨量少，生物力学性能弱。综合已有研究结果，我们推测mir-214可能在新生骨的形成中起着一定的作用，通过调控mir-214可以增强OCN、ALP等调节因子的表达，增强新生血管形成的能力，促进新生骨的形成及改建。 本研究将重点检测mir-214在新生骨中的表达，mir-214的拮抗剂及激动剂对mir-214表达的影响以及不同表达水平的mir-2

利用模拟体液进行仿生矿化可在天然聚合物上形成骨状磷灰石增强骨传导能力和生物相容性，并降低免疫排斥反应。尽管如此，天然聚合物上的骨状磷灰石层的矿化仍有待改进。氧化石墨烯富含羰基等官能团(- COOH)和羟基(- OH)，它们能提供促进仿生矿化和大鼠骨髓基质细胞的增殖。在这项研究中，我们加入0%，0.05%，0.1%和0.2%的氧化石墨烯的w/v浓度，将支架置入胶原蛋白(Col)中，将支架分别浸泡1天、7天和14天。体外环境扫描电子显微镜(ESEM)，能量色散光谱(EDS)，热重量分析(TGA)，微CT，钙定量分析和细胞分析用于评估支架上骨状磷灰石的形成。将支架植入大鼠颅骨缺损中，分析其骨再生能力。结果表明，氧化石墨烯-胶原蛋白支架具有多孔且相互连接的结构，其表面均匀分布着骨状磷灰石复层。基于EDS的分析，0.1% GO - Col - Ap组的Ca/P比值与天然骨组织的Ca/P比值相等。通过TGA分析、微CT评估和钙检测，在0.1% GO - Col - Ap组中观察到更多的磷灰石定量分析。此外，0.1% GO - Col - Ap组的r-BMSCs黏附率和在体内，Col - Ap组的成骨率是Col - Ap组的2倍。我们的研究提供了一种将氧化石墨烯引入骨组织工程支架以增强仿生矿化的新方法。