摘要
目的对去细胞瓣进行聚乙二醇(PEG)化改性和血管内皮细胞生长因子(VEGF)共价修饰,以改善去细胞瓣力学性能和生物学性能,并联合内皮祖细胞构建心脏瓣膜复合支架。方法枝化状PEG末端的丙烯酰基与引入到去细胞瓣上的巯基,通过迈克尔加成反应完成去细胞瓣的PEG化,并作去细胞瓣PEG化前后以及天然主动脉瓣的生物力学测定;通过PEG化去细胞瓣上未饱和的丙烯酰基与VEGF中半胱氨酸残基上的巯基发生另一个迈克尔加成反应,对去细胞瓣进行VEGF共价修饰,免疫荧光测定VEGF修饰效果;在VEGF修饰的PEG化去细胞瓣、去细胞瓣和PEG化去细胞瓣上种植内皮祖细胞(EPCs),培养10d后行瓣膜上DNA含量测定、苏木素-伊红染色和扫描电镜。结果力学测试显示:PEG化去细胞瓣的最大抗张强度较单纯去细胞主动脉瓣明显提高(P<0.05),而与天然主动脉瓣相比无差异(P>0.05);免疫荧光检测显示:VEGF可有效地共价修饰PEG化去细胞瓣;与PEG化去细胞瓣和单纯去细胞瓣相比,VEGF修饰的PEG化去细胞瓣明显促进EPCs的增殖,并且可在瓣膜表面形成一层连续的单细胞层。结论 PEG化可明显改善去细胞瓣的力学性能,并且VEGF修饰PEG化去细胞瓣可促进支架上黏附细胞的增殖,有利于改善组织工程心脏瓣膜的构建。
Objective In order to improve the mechanical and biological properties of decellularized valves,decellularized valves were PEGylated and then covalently modified by VEGF,and endothelial progenitor cells were combined to fabricate composite heart valves.Methods PEGylation of decellularized valves were completed by using a Michael-type addition reaction,that is,propylene acyl of branched polyethylene glycol was reacted with the thiol introduced into decellularized valves,and biomechanical properties were compared between the decellularized valves,PEGylated decellularized valves and native aortic valves;PEGylated decellularized valves were covalently modified by VEGF through another Michael-type addition reaction,in other words,the unsaturated propylene acyls of polyethylene glycol were reacted with thiol groups on cysteine residues of VEGF,the modified effect of VEGF was determined by immune fluorescence;the EPCs were seeded respectively on decellularized valves,PEGylated decellularized valves and PEGylated decellularized valves modified by VEGF,after 10 days of culture,DNA content,hematoxylin-eosin and scanning electron microscope were performed.Results Mechanical tests showed:the maximal tensile strength of PEGylated decellularized valves were significantly higher than those of decellularized valves(P<0.05),but similar to those of native aortic valves(P>0.05);immune fluorescence showed that:PEGylated decellularized valves could be modified effectively by VEGF through covalent bonding;compared with PEGylated decellularized valves and decellularized valves,VEGF-modified PEGylated decellularized valves significantly promote the proliferation of EPCs,and may form a confluent monolayer cells on the valve surface.Conclusions PEGylation can obviously improve the mechanical properties of decellularized valves;modification of PEGylated decellularized valves by VEGF can promote the proliferation of adhesion cells on valve scaffolds,which is helpful to improve the construct of tissue engineering heart valves.
出处
《中华临床医师杂志（电子版）》
CAS
2011年第10期2890-2895,共6页
Chinese Journal of Clinicians(Electronic Edition)
基金
国家863计划资助(2009AA03Z420)
国家自然科学基金(30872540)
关键词
心脏瓣膜
组织支架
聚乙烯二醇类
血管内皮生长因子A
去细胞瓣
Heart valves
Tissue scaffolds
Polyethylene glycols
Vascular endothelial growth factor A
Decellularized valves
