Preparation and performance detection of small-diameter tissue-engineered blood vessels / 中国组织工程研究

ABSTRACT

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 groupscontrol 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 thatin 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.