不同处理条件下脱细胞脐动脉制备小口径组织工程人工血管生物力学性质的对比研究

Different biomechanical properties of human acellular umbilical artery: comparative studie using three different processing methods

目的:测定使用3种不同方法处理人脱细胞脐动脉支架后,分别植入种子细胞组装的小口径人工血管生物力学性质,为小口径人工血管的研究提供参考。方法:取同一条人脱细胞脐动脉,均分3段并分三组:A组为0.9%氯化钠溶液处理组,B组为75%乙醇处理组,C组为0.5%戊二醛处理组。然后在特制的搏动培养装置中,将种子细胞的混悬液种植于血管支架内表面;最后对其进行组织学及生物力学性能检测,并相互比较。结果:制备的三组小口径人工血管中B组及C组的塑形性较A组好;力学测试结果显示:抗张力强度C组最大(4.98±0.16)N,B组次之(3.27±0.11)N,A组最小(1.79±0.13)N(B组与A组比较P=0.023;C组与A组比较P=0.027);抗爆破压强度:B组(541±20)mmHg(1mmHg=0.133kPa),C组(605±24)mmHg,两组均大于A组(386±18)mmHg(B组与A组比较P=0.035;C组与A组比较P=0.042);位移-负荷曲线分析显示:,C组的斜率最大,B组次之,A组最小;HE染色结果显示:AB两组血管的内皮细胞数量、覆盖程度均优于C组;扫描电镜的检测结果显示:A组与B组的细胞种植情况也好于C组;结论:使用75%乙醇或0.5%戊二醛处理后的脱细胞脐动脉塑形性好,血管形态结构好、生物力学性质均明显较0.9%氯化钠液处理组好;而75%乙醇处理后的脱细胞脐动脉在其顺应性方面较0.5%戊二醛处理后更接近于生理状态、且种子细胞种植效果相对较好,因此75%乙醇处理的人脱细胞脐动脉是较理想的血管支架材料。

Objective：To campare different biomechanical properties of human acellular umbilical artery,under three different processing methods.Methods：Acellular umbilical artery was prepared using enzymatic digestion method under the plasticity situation to take off the cellular components of human umbilical artery （n =10）.Prepared acellular umbilical artery was then cut equally in lenth,and divided into three groups according different processing methods：0.9％ sodium chloride as group A,75％ ethanol as group B and 0.5％ glutaraldehyde as group C.Matured seed cells were planted onto the internal surface of the differently treated acellular umbilical artery stent with special pulsatility culture equipment.The biomechanical properties of the arteries from three groups were then analyzed and compared.Results：The biomechanical test results showed that tensile strength of group A,B and C were（1.79 ± 0.13）N,（3.27 ± 0.1 1）N and（4.98 ± 0.16）N respectively （P ＜ 0.05）; Burst pressure resistance strength of group A,B and C were（386 ± 18）mmHg （1mmHg =0.133 kPa）,（541 ± 20） mmHg and （605 ± 24） mmHg respectively （P ＜ 0.05）.In displacement-load curve analysis,the slope of group C was the maximum,followed by group B,and then group A.The HE staining revealed that the vascular endothelial cells coverage degree in group A and B was superior to group C; Scanning electron microscopy test results showed that the cell growth in group A and group B was much better than group C.Conclusion：Pretreating the acellular umbilical artery using 75％ ethanol or 0.5％ glutaraldehyde could retain better plasticity,morphological structure,and biomechanical properties.However,combined with the properties of flexibility and cell seeding,the acellular ateries treated with 75 ％ ethanol were superior to others.Therefore,the acellular umbilical artery pretreated with 75％ ethanol could be an ideal choice as a scaffold for small diameter tissue engineering artificial blood vessel.