聚乙二醇交联去细胞瓣构建组织工程瓣膜复合支架  

Crosslinking effects of branched PEG diacrylate on decellularized porcine aortic valve scaffolds for tissue engineering

作　　者：邹明晖[1] 周建良[1] 陈义初[1] 胡行健[1] 邓诚[1] 史嘉玮[1] 董念国[1] 

机构地区：[1]华中科技大学同济医学院附属协和医院心外科,武汉430022

出　　处：《中华临床医师杂志（电子版）》2011年第8期2191-2196,共6页Chinese Journal of Clinicians(Electronic Edition)

基　　金：国家自然科学基金(30872540);国家863计划资助(2009AA03Z420)

摘　　要：目的采用分子量20kDa的枝化状丙烯酰化聚乙二醇(PEG)交联巯基化去细胞瓣,构建组织工程瓣膜复合支架,并对支架的结构稳定性、力学性能和细胞相容性进行初步检测。方法取猪新鲜主动脉瓣叶,进行脱细胞瓣处理,制备去细胞瓣并巯基化。戊二醛固定去细胞瓣,PEG交联巯基化去细胞瓣。形态学观察去细胞及交联效果,差示扫描量热法(DSC)测定热收缩温度,Ⅰ型胶原酶溶液测定其抗酶性分解能力,拉伸实验测定其抗拉强度和弹性模量,并采用AlamarBlue法测定支架对MRC-5人胚肺细胞的细胞毒性。结果 HE染色和扫描电镜(SEM)显示去细胞完全,细胞外基质保存完整;PEG交联后瓣叶变薄,纤维增粗呈束。PEG交联瓣的热收缩温度为(75.16±0.69)℃,与去细胞瓣[(67.63±1.09)℃]相比有显著提高,其差异有统计学意义(P<0.05)。PEG交联瓣6h及12h酶性分解率分别为(17.52±1.69)%和(48.83±2.67)%,与去细胞瓣[(64.91±2.05)%和(98.23±1.20)%]相比,分解率显著下降。PEG交联瓣抗拉强度较去细胞瓣显著为高,并达到天然瓣水平,弹性模量则远高于其他各组。细胞毒性试验显示PEG组和对照组活力细胞差别为(1.82±0.03)%,无统计学意义(P>0.05)。结论 PEG交联可显著改善去细胞瓣结构稳定性和力学性能,而无明显细胞毒性,有望用于组织工程瓣膜复合支架的构建。Objective To assess the structural stability,mechanical properties and cytocompatibility of branched PEG diacrylate(PEGDA)crosslinked decellularized porcine aortic valve scaffolds.MethodsFresh decellularized valve scaffolds were introduced thiol group and crosslinked with PEG,and 0.625% glutaraldehyde was used to crosslink the decellularized valves.HE staining and Scanning electronic microscope(SEM)were used to observe the histological characteristics.The shrinkage temperature(Ts)of native,non-,GA-,and PEG crosslinked decellularized scaffolds was determined by differential scanning calorimetry(DSC).Resistance to enzymatic degradation was tested by 40 U/mlⅠtype collagenase D-hanks solution.Tensile test was utilized to measure the tensile strength and young's modulus.Cytocompatibility was also determined by MRC-5 human embryonic lung fibroblasts.Results HE staining and SEM found that the extracellular matrix was preserved well after decellularization procedure,while PEG crosslinking resulted in the reduction of tissue thickness and clustering of collagen fibers.The Ts of PEG group is(75.16±0.69)℃,and significantly higher than that of the decellularized group(P<0.05).The enzymatic degradation rates at 6 h and 12 h of PEG group were(17.52±1.69)% and(48.83±2.67)%,which were much lower when compared with the decellularized group.Tensile test showed that the tensile strength of PEG group remarkably enhanced to the level of the native valves,while the young's modulus was much higher than that of the latter.Cytocompatibility test found there was not significant difference between the PEG group and the decellularized group(P>0.05).Conclusions PEG crosslinking increased the structural stability and mechanical properties of the decellularized porcine heart valve scaffolds,appeared good cytocompatibility,and may be a promising method in the study of tissue engineering valve hybrid scaffolds.

关 键 词：聚乙烯二醇类 组织支架 交联试剂 去细胞瓣 

分 类 号：R318.08[医药卫生—生物医学工程]