RGD接枝改性复合水凝胶的制备及其基于低强度脉冲超声刺激的细胞分化研究

发布时间：2018-08-03 15:47

【摘要】：骨组织工程研究为三维支架的植入提供了一种潜在的方法。然而,在三维支架植入骨再生方面仍然存在一些挑战,包括创建结构和力学性能与自然骨相匹配的再生骨组织,以及成功实现支架与宿主骨的整合。其中,新骨形成和血管形成的程度被认为是骨组织工程临床应用的关键因素。水凝胶的含水量丰富,与人体组织极为相似,可用作组织工程支架材料。然而,水凝胶的亲水性表面不利于蛋白质的吸附,不利于粘附和细胞的生长,从而不利于新骨和血管化的形成,因此利用胺基与醛基之间的希夫碱反应将RGD接枝在多糖上对其表面亲水性进行改性。本研究使用RGD接枝氧化海藻酸钠/N-琥珀酰壳聚糖(RGD-OSA/NSC)复合水凝胶为基体材料,以低强度脉冲超声波(LIPUS)作为机械刺激的方法以期实现高水平的血管形成和新骨形成。为了评价LIPUS作用下复合水凝胶材料的血管化能力和成骨的性能,我们进行了较系统的体外成骨诱导和内皮诱导实验研究。结果显示RGD-OSA/NSC复合水凝胶在细胞粘附,增殖以及分化等方面表现出良好的生物学性能。MTT细胞活性分析表明,LIPUS与RGD共同作用实验组细胞的总数量最多,成骨诱导中ALP活性／染色和矿化结节以及内皮诱导中免疫染色检测实验中,比较LIPUS-RGD-OSA/NCS实验组与Control-RGD-OSA/NCS实验组及LIPUS-OSA/NCS实验组,发现前者的阳性率均高于后两者之和,表明LIPUS和RGD在促进hMSCs的增殖和分化过程中有协同作用。这些结果表明同时使用RGD修饰和LIPUS可能为骨组织工程支架植入过程中新骨形成和血管形成中提供一种有效地方法。
[Abstract]:Bone tissue engineering provides a potential method for the implantation of three-dimensional scaffolds. However, there are still some challenges in three-dimensional scaffold bone regeneration, including the creation of regenerated bone tissue with structural and mechanical properties matching with natural bone, and the successful integration of scaffold and host bone. Among them, the degree of new bone formation and angiogenesis is considered to be a key factor in clinical application of bone tissue engineering. Hydrogels are rich in water content and very similar to human tissues and can be used as scaffolds for tissue engineering. However, the hydrophilic surface of hydrogels is not conducive to protein adsorption, adhesion and cell growth, which is not conducive to the formation of new bone and vascularization. Therefore, the surface hydrophilicity of RGD was modified by the Schiff base reaction between amino group and aldehyde group. In this study, RGD grafted sodium alginate / sodium succinyl chitosan (RGD-OSA/NSC) composite hydrogel was used as matrix material, and low intensity pulsed ultrasonic (LIPUS) was used as mechanical stimulation method to achieve high level of angiogenesis and new bone formation. In order to evaluate the vascularization ability and osteogenic properties of the composite hydrogels under the action of LIPUS, we conducted a systematic in vitro osteogenesis and endothelial induction experiments. The results showed that RGD-OSA/NSC composite hydrogels exhibited good biological properties in cell adhesion, proliferation and differentiation. The positive rates of ALP activity / staining and mineralized nodules in osteogenic induction and the immunostaining in endothelial induction were compared between LIPUS-RGD-OSA/NCS group, Control-RGD-OSA/NCS experimental group and LIPUS-OSA/NCS experimental group, and the positive rates of the former group were higher than that of the latter two groups. These results suggest that LIPUS and RGD have synergistic effects in promoting the proliferation and differentiation of hMSCs. These results suggest that both RGD modification and LIPUS may provide an effective method for new bone formation and angiogenesis during bone tissue engineering stent implantation.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R318.08

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