负载bFGF氧化聚古洛糖醛酸水凝胶的血管化性能研究

发布时间：2018-03-10 12:53

本文选题：肝素明胶偶联物　切入点：氧化聚古洛糖醛酸　出处：《天津大学》2012年硕士论文　论文类型：学位论文

【摘要】：应用仿细胞外基质(ECM)思路设计的水凝胶,负载外源性生长因子后可直接作用于缺血性患处,在体内降解过程中不断释放出生长因子而刺激细胞增殖、血管形成以及组织修复,从而实现治疗性血管的形成。本文制备了肝素明胶偶联物(HGC),并采用氧化聚古洛糖醛酸(PAG)水凝胶作为仿ECM载体,探讨了HGC保护的碱性成纤维细胞生长因子(bFGF)从水凝胶中的释放行为,并通过鸡胚绒毛尿囊膜(CAM)模型和大鼠背部皮下气囊模型评价了其血管化性能。通过酸性水解法用海藻酸钠制备了聚古洛糖醛酸(PG),而后以低温高碘酸钠氧化法制备出PAG。通过酰胺化反应向明胶引入了外源性氨基,从而提高了其反应活性。将肝素偶联到明胶侧链上,形成了结构类似于蛋白聚糖的HGC,而后将结合有bFGF的HGC、PAG以及氨基化明胶共交联形成了PAG水凝胶。结果显示,与海藻酸盐水凝胶相比,PAG水凝胶的降解速率明显减缓;肝素/bFGF重量比为2000时即可保证bFGF物理固定于PAG水凝胶网络中,并使其缓慢释放,证实HGC成分的加入对PAG水凝胶体系作为生长因子载体的重要性。 CAM模型结果显示,PAG水凝胶体系中HGC和bFGF的加入量对CAM血管形成有着显著的影响。0.5% HGC的加入量可以有效地保留bFGF的生物活性,从而促进新生血管的形成。bFGF和内皮细胞生长因子(VEGF)的协同作用对CAM血管形成有着明显的促进作用。大鼠背部皮下气囊模型结果显示,PAG水凝胶体系中HGC和bFGF的加入量对血管形成同样有着重要的影响,1% HGC的加入量可以有效地促进新生血管的形成,而水凝胶中的bFGF浓度达到100 ng/mL后,再继续增加bFGF浓度时所形成的血管密度反而降低。
[Abstract]:The hydrogels designed with ECM mimic extracellular matrix can directly act on ischemic affected areas after loading exogenous growth factors, and release growth factors to stimulate cell proliferation, angiogenesis and tissue repair during degradation in vivo. In this paper, the heparin gelatin conjugate HGCX was prepared, and the oxidized polyuronic acid hydrogel was used as the imitating ECM carrier. The release behavior of basic fibroblast growth factor (bFGF) protected by HGC from hydrogels was investigated. The vascularization properties were evaluated by chicken embryo chorioallantoic membrane (chorioallantoic) model and rat dorsal subcutaneous balloon model. Polyglumuronic acid (PGN) was prepared by acid hydrolysis with sodium alginate, and then PAG was prepared by oxidation of sodium periodate at low temperature. Exogenous amino groups were introduced into gelatin by amidation reaction. By coupling heparin to the side chain of gelatin, HGCs with similar structure to proteoglycan were formed, and then PAG hydrogels were co-crosslinked with bFGF and amino gelatin. When the weight ratio of heparin / bFGF is 2000, the bFGF can be physically immobilized in the PAG hydrogel network and released slowly. The importance of the addition of HGC to the PAG hydrogel system as a growth factor carrier was confirmed. The results of CAM model showed that the addition of HGC and bFGF in PAG hydrogel system had a significant effect on CAM angiogenesis. The addition of 0.5% HGC could effectively preserve the biological activity of bFGF. Therefore, the synergistic effect of bFGF and endothelial growth factor (VEGF) on CAM angiogenesis was found. The results of rat dorsal subcutaneous balloon model showed that HGC and bFGF were added into PAG hydrogel system. The addition of 1% HGC can effectively promote angiogenesis. However, when the concentration of bFGF in the hydrogel reached 100 ng/mL, the vascular density decreased when the concentration of bFGF continued to increase.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R318.0

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