枝化状聚乙二醇交联改善猪去细胞主动脉瓣的力学性能比较

目的 采用不同相对分子质量枝化状聚乙二醇(PEG)交联巯基化的猪去细胞瓣,观察其对去细胞瓣膜力学性能的影响.方法 将25例猪去细胞主动脉瓣随机分为5组:PEG3400组、PEG8000组、PEG12000组、PEG20000组和对照组,常温反应时间4 h.测定残余巯基计算交联效率;静态拉伸实验测定力学性能.结果 4 h交联率依次为92.40%、89.88%、87.87%和87.46%,相对分子质量越小,交联效率越高,PEG3400组与其他各组比较,差异有统计学意义(P＜0.05);力学测试显示,相对分子质量越大,力学强度越高,呈一定的正相关,PEG12000和PEG20000组抗拉强度分别为(3.22±0.41)MPa和(3.19±0.15)MPa,与对照组比较,差异有统计学意义(P＜0.05).结论 相对分子质量12000 Da和20000 Da枝化状聚乙二醇交联可有效改善猪去细胞瓣的力学性能,有望用于构建新型复合的组织工程瓣膜支架材料的研究应用.

Abstract：

Objective Branched polyethylene glycols (PEG) with different molecular weight were cross-linked to the porcine decellularized aortic valve (DAV) and the effects of PEG cross-linking on the mechanical properties were investigated. Methods A total of 25 porcine DAVs were randomly assigned into 5 groups: PEG3400, PEG8000, PEG12000, PEG20000 and control. The reactive time was 4 h at room temperature. The efficiency of crosslinking was calculated by measuring the residual thiol group. The mechanical properties were obtained by static tensile test. Results The efficiency of crosslinking was 92. 40% , 89. 88% , 87. 87% and 87. 46% in PEG3400, PEG8000, PEG12000, PEG20000 groups, respectively. As compared with other groups, the PEG3400 group had significantly greater increase in the crosslinking degree (P ＜ 0. 05). Tensile test showed the tensile strength of PEG12000 and PEG20000 groups was (3. 22 ±0.41) and (3. 19 ±0. 15) MPa, respectively, and significantly different from that in control group (P ＜ 0. 05). The tensile strength and young' s modulus had a positive correlation with the molecular weight of PEG. Conclusion Branched PEG with the molecular weight of 12 000 Da and 20 000 Dacan effectively crosslink to the porcine decellularized aortic valves and improve their mechanical behaviors, and has the potential to be used as the material of fabricating new hybrid scaffold of tissue engineering heart valves.

Comparisons of the mechanical properties of the porcine decellularized aortic valves by cross-linking with branched polyethylene glycol

Objective Branched polyethylene glycols (PEG) with different molecular weight were cross-linked to the porcine decellularized aortic valve (DAV) and the effects of PEG cross-linking on the mechanical properties were investigated. Methods A total of 25 porcine DAVs were randomly assigned into 5 groups: PEG3400, PEG8000, PEG12000, PEG20000 and control. The reactive time was 4 h at room temperature. The efficiency of crosslinking was calculated by measuring the residual thiol group. The mechanical properties were obtained by static tensile test. Results The efficiency of crosslinking was 92. 40% , 89. 88% , 87. 87% and 87. 46% in PEG3400, PEG8000, PEG12000, PEG20000 groups, respectively. As compared with other groups, the PEG3400 group had significantly greater increase in the crosslinking degree (P ＜ 0. 05). Tensile test showed the tensile strength of PEG12000 and PEG20000 groups was (3. 22 ±0.41) and (3. 19 ±0. 15) MPa, respectively, and significantly different from that in control group (P ＜ 0. 05). The tensile strength and young' s modulus had a positive correlation with the molecular weight of PEG. Conclusion Branched PEG with the molecular weight of 12 000 Da and 20 000 Dacan effectively crosslink to the porcine decellularized aortic valves and improve their mechanical behaviors, and has the potential to be used as the material of fabricating new hybrid scaffold of tissue engineering heart valves.