体内环境培养的小口径组织工程血管

Small-caliber tissue engineered blood vessels cultivated in vivo

背景:人造血管是临床组织修复领域广泛应用的重要器官,但小口径人造血管易于栓塞、难以长期保持通畅,而组织工程血管虽有永久替代作用,培养时间长,不符合血管修复的临床实际。寻找既能及时修复血管、恢复血运,又能在体内形成生物性血管保持长期通畅,是最理想的血管修复重建方法。目的:观察以改性猪小肠黏膜下层组织为支架,在体内血流条件下培养小口径组织工程血管的可行性。方法:自犬隐动脉分离出血管内皮细胞、平滑肌细胞,与胶原蛋白凝胶均匀混合,分别种植于小肠黏膜下层膜表面,包绕3mm聚乙烯管制成30个3层管状支架,植入犬股动脉缺损处进行桥接吻合为实验组;植入犬皮下组织为对照组。术后进行彩超、组织学检测评价血管的形成过程和免疫组化鉴定。结果与结论:术后12周,实验组14个血管支架保持通畅,有明显的血管生物结构形成,种子细胞生长增殖良好,管腔有完整内皮细胞覆盖,平滑肌细胞形态、分布良好;对照组管腔结构不完整,种子细胞增殖弱,腔面无内皮细胞覆盖。结果表明通过体内组织工程技术可在血流条件下培养形成小口径组织工程血管。

BACKGROUND：The artificial blood vessel is vital organs widely used in the field of clinical tissue repair,but small-caliber artificial blood vessels are prone to embolism,and difficult to maintain smooth for a long time,although tissue engineered vessels can be used as a permanent replacement,it costs a long time to culture,which does not meet the clinical practice of vascular repair.It is an ideal method of vascular repair and reconstruction that timely repair blood vessels,restore blood flow,also form biological vessels in vivo and maintain long-term patency.OBJECTIVE：To study the feasibility of cultivating the small-caliber blood vessels under in vivo blood flow circulation with modified porcine small intestinal submucosa as the scaffold.METHODS：The seed cells including vascular endothelial cells and smooth muscle cells were separated from the canine saphenous artery,which were mixed with collagen gel and planted on the small intestinal submucosa films,these films were wrapped up into 30 three-layer tubular scaffolds around 3 mm diameter polyethylene tubes,and the scaffolds were implanted into the defect of canine femoral artery for anastomosis as experimental group,while those were implanted into the subcutaneous tissue served as control.After operation,the formation process of blood vessels was evaluated by Doppler color ultrasound,histology detection,immunohistochemistry examination.RESULTS AND CONCLUSION：At 12 weeks postoperatively,14 scaffolds had kept well patency in the experimental group,vascular biologic structures evidently formed,the seed cells well proliferated,the lumen surface was completely covered with endothelial cells,smooth muscular cells morphology and distribution were good.In control group,tube structure was incomplete,seed cells proliferated poorly,lumen surface was covered without endothehal cells.By in vivo tissue engineering technology,the small-caliber blood vessels could be cultivated directly under the circulation of blood flow.