生物活性材料促进关节软骨损伤修复和再生研究

发布时间：2018-06-23 14:43

本文选题：关节软骨 + 软骨组织工程　；参考：《浙江大学》2015年博士论文

【摘要】：肌肉骨骼和关节疾病影响着数千万人的健康。关节软骨是一种透明光滑的组织,它覆盖在骨端关节头的表面,起到减少相邻两骨间的摩擦等作用。但它是一种无血管无神经的组织,所以一旦缺损,很难自发修复。关节软骨损伤是临床上十分常见的病症,也是骨科和运动医学中公认的治疗难题。由于软骨无血管无神经,营养供应不佳,传统观点认为软骨损伤无法自发修复,如果不采取外加手段干预治疗,会导致进一步的软骨磨损,甚至引发骨关节炎；另一方面,尽管骨软骨损伤有一定的自发修复能力,但修复组织常出现软骨终末分化的现象,对其结构和功能造成不可逆的损害,严重影响患者的生活工作质量。针对目前软骨损伤修复过程中碰到的难题,本研究分别构建生物活性材料以开发针对性治疗方案。首先通过对新西兰大白兔体内造模,我们评估了部分软骨损伤、全层软骨损伤和骨软骨损伤的自发修复能力。结果显示部分软骨损伤无自发修复能力；全层软骨损伤有一定自发修复能力,且观察到间质干细胞(MSCs)从缺损边缘向缺损中心流动；骨软骨损伤有一定自发修复能力,但修复组织出现软骨终末分化现象。进而针对部分软骨损伤修复,通过使用软骨损伤离体模型和生物材料模拟体内微环境,评估了MSCs在部分和全层软骨损伤表面的粘附性和细胞形态,并进一步利用Transwell实验评估外源性与内源性SDF.1对体外培养细胞的诱导迁移作用。离体模型与体外实验结果显示,与软骨微环境和二型胶原(col Ⅱ)支架相比,软骨下骨微环境和一型胶原(col I)支架更有利于MSCs粘附,且SDF-1能够显著提高MSCs的迁移。在此基础上构建的col I复合SDF.1生物活性支架为部分软骨缺损创造了合适的微环境,动物实验验证显著提高了兔部分软骨损伤自发修复能力。最后针对骨软骨损伤修复,体外实验结果显示通过抑制经典Wnt/β-catenin通路活性,PTHrP能够显著降低茜素红染色和终末分化相关基因的表达。对新西兰大白兔体内骨软骨损伤造模,缺损处移植胶原.蚕丝双层支架,并在三个不同时间点关节腔注射PTHrP(术后4.6,7.9和10.12周)。术后4.6周PTHrP治疗组的修复再生效果(软骨和软骨下骨的重建)要优于其他时间点治疗组,软骨终末分化现象减少(钙化、骨化、基质降解),BMSCs成软骨能力提高(细胞形态、col II和糖胺聚糖合成)。此外,PTHrP的应用时间影响PTHrP受体的表达,进而影响PTHrP的治疗效果。综上,对于部分软骨损伤,我们应用col Ⅰ生物膜材料复合基质细胞衍生因子SDF-1构建生物活性材料促进C-MSCs和SM-MSCs的迁移粘附,进而开启软骨自发修复；对于骨软骨损伤,我们应用胶原.蚕丝双层支架复合甲状旁腺激素相关蛋白PTHrP抑制软骨终末分化,促进成软骨过程,进而提高软骨自发修复质量。该研究结果无论对于解释软骨损伤治疗的生物学本质,还是最终临床转化治疗软骨损伤都有至关重要的意义。
[Abstract]:Musculoskeletal and joint diseases affect the health of millions of people. Articular cartilage is a transparent, smooth tissue that covers the surface of the end of the end of the bone and plays a role in reducing the friction between the two adjacent bones. But it is a kind of no vascular and non nerve tissue, so it is difficult to repair spontaneously once the defect is damaged. The articular cartilage injury is ten in clinical. The common disease is also a recognized treatment problem in the Department of orthopedics and sports medicine. Because the cartilage is no blood vessel and no nerve, the nutritional supply is poor, the traditional view that the cartilage damage can not be repaired spontaneously, if the treatment is not taken, it will lead to further cartilage wear and even osteoarthritis; on the other hand, despite the bone cartilage The injury has a certain ability to repair spontaneously, but the repair tissue often appears cartilage end differentiation, causing irreversible damage to its structure and function, which seriously affects the quality of life and work of the patients. In view of the problems encountered in the process of repair of cartilage injury, this study develops bioactive materials to develop targeted treatment schemes respectively.
First of all, we evaluated the ability of partial cartilage injury, total cartilage injury and spontaneous repair of osteochondral damage through the modeling of New Zealand white rabbits. Results showed that partial cartilage injury had no spontaneous repair ability, and there was a certain spontaneous repair ability of the whole layer cartilage injury, and the interstitial stem cells (MSCs) were observed from the defect edge to the defect. There is a spontaneous repair ability of osteochondral injury, but there is a phenomenon of cartilage terminal differentiation in repair tissue.
In view of the repair of partial cartilage damage, the adhesion and cell morphology of MSCs on the surface of partial and total cartilage damage were evaluated by using the model of cartilage damage in vitro and biomaterial to simulate the microenvironment in vivo, and the induced migration of exogenous and endogenous SDF.1 on the cultured cells was evaluated by Transwell experiment. The body model and in vitro experimental results show that the subchondral bone microenvironment and the type of collagen (Col I) scaffold are more conducive to MSCs adhesion compared with the cartilage microenvironment and the type two collagen (Col II) scaffold, and SDF-1 can significantly improve the migration of MSCs. On this basis, the col I compound SDF.1 bioactive scaffold has created a suitable part of the cartilage defect. The microenvironment of animal experiments proved that the ability of spontaneous repair of partial cartilage injury in rabbits was significantly improved.
At last, in response to the repair of osteochondral damage, in vitro experiments showed that by inhibiting the activity of the classic Wnt/ beta -catenin pathway, PTHrP could significantly reduce the expression of alizarin red staining and terminal differentiation related genes. PTHrP (4.6,7.9 and 10.12 weeks after operation). The regenerative effect of the PTHrP treatment group (cartilage and subchondral bone reconstruction) at 4.6 weeks after the operation was better than the other time point treatment group. The cartilage end differentiation was reduced (calcification, ossification, matrix degradation), and the energy of BMSCs was improved (cell morphology, col II and glycosaminoglycan synthesis). In addition, PTHrP The application time affects the expression of PTHrP receptor, thereby affecting the therapeutic effect of PTHrP.
To sum up, for partial cartilage damage, we use Col I biofilm material complex matrix cell derived factor SDF-1 to construct bioactive materials to promote the migration and adhesion of C-MSCs and SM-MSCs, and then open the cartilage to repair spontaneously; for osteochondral damage, we apply collagen. Silk double layer scaffold composite parathyroid hormone related protein PTHrP It is of great significance to explain the biological nature of cartilage damage treatment and to the final clinical transformation of cartilage damage.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：R687.4;R318.08

【共引文献】