BACKGROUND:Due to limited sources,poor hemocompatibility and poor anticoagulation performance,small-diameter tissue-engineered blood vessels cannot be applied in clinical practice.OBJECTIVE:To explore the physicochemical and mechanical properties of sheep carotid arteries after the decellularization in order to find appropriate materials for the preparation of tissue-engineered blood vessels.METHODS:Fresh carotid arteries from sheep were randomly divided into two groups:control group,in which,the sheep carotid arteries were cryopreserved for use after trimming and cleaning;experimental group,in which,after trimming and cleaning,the carotid arteries were decallularized by Triton X-100.sodium deoxycholate and EDTA for 24 hours,rinsed for 72 hours,digested with RNA/DNA enzymes for 24 hours,rinsed for 24 hours and reserved for later use.In both groups,blood samples were subjected to hematoxylin-eosin staining,collagen fiber staining,elastic fiber dyeing,and electron microscopy observation.The physical and chemical properties of the blood vessels are tested by tensile strength,wall tension and thickness.RESULTS AND CONCLUSION:(1) The collagen fibers in both two groups were neat and compact in alignment,with no obvious fracture.(2) Hematoxylin-eosin staining showed that:in the control group,the nuclei were distributed in the inner membrane,middle lamella and outer membrane of the vessels,and the fibers ran regularly;in the experimental group,the fibers ran in order but loosely,and there were no nuclei in the inner membrane,middle lamella and outer membrane of the vessels.(3) Elastic fibers in the control group were regular in alignment and mainly distributed in the middle lamella and outer membrane of the vessels,while in the experimental group,the elastic fibers ran regularly but loosely,and mainly distributed in the middle lamella and outer membrane of the vessels.(4) Under the scanning electron microscope,the originally formed vessels were observed in the experimental group,with no cell residues,and the collagen fibers ran orderly with no fracture and with uniform pore structure.(5) The vessel thickness was lower in the experimental group than the control group (P ＜ 0.01),but the tensile strength showed no difference between the two groups,which was 46.55 kPa in the two groups.To conclude,the decelluarized sheep carotid artery can retain the necessary mechanical properties of the blood vessels after achieving the maximum removal of antigenicity.%背景:由于材料来源问题、材料血液相容性和抗凝性能不佳,致使小口径组织工程血管无法应用于临床.目的:探究经过脱细胞处理后绵羊颈动脉的理化性能及力学性能,为制备组织工程血管寻找合适材料.方法:获取新鲜离体绵羊颈动脉,分2组处理,对照组进行修剪及清洗处理,冻存备用;实验组进行修剪及清洗处理后,以Triton X-100+脱氧胆酸钠盐+EDTA进行脱细胞处理24 h,漂洗72 h,接着以RNA酶/DNA酶消化24 h,漂洗24 h后冻存备用.将两组血管进行苏木精-伊红染色、胶原纤维染色、弹力纤维染色及电镜扫描观察,检测血管的抗拉力强度、血管壁张力及厚度.结果与结论:①胶原纤维染色显示,对照组胶原纤维排列整齐,致密,无明显断痕;实验组胶原纤维排列整齐,致密,无明显断痕;②苏木精-伊红染色显示,对照组细胞核分布在血管的内膜、中层、外膜,纤维走行规则;实验组纤维走行规则,较松散,内膜、中层、外膜无明显细胞核分布;③弹力纤维染色显示,对照组弹力纤维分布规则,整齐,主要在于血管的中层及外膜;实验组弹力纤维走行规则,但较疏松,主要分布在于血管中层及外膜;④电镜扫描显示,实验组血管保持原有的形态,未见细胞结构残留,胶原纤维走行规则,连续性完整,孔隙结构较均匀;⑤实验组血管厚度低于对照组(P＜0.01),两组拉力强度无差异,均可承受46.55 kPa的压力;⑥结果表明,经脱细胞处理的绵羊颈动脉,在最大程度去除抗原性的基础上保留了血管必要的力学性能.
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