CD34抗体修饰的脱细胞血管支架的体内内皮化

In vivo recellularization of decellularized vascular scaffolds cross-linked with anti-CD34 antibody

目的研究CD34抗体修饰的脱细胞血管支架植入动物体内后募集循环中的内皮祖细胞参与再内皮化过程的性能。方法新鲜的羊前肢动脉经反复冻融和超高压处理,SDS彻底去除细胞,通过光交联法将CD34抗体固定于脱细胞血管内腔面。20只新西兰大白兔右下腹做一带蒂皮瓣,皮瓣供血动脉为股动脉的分支血管,血管移植部位选取股动脉,做1cm长的全段缺损,随机分为2组(n=10),实验组选用CD34抗体修饰的脱细胞血管支架,对照组用未修饰的脱细胞血管支架,显微外科端端吻合替代缺损的兔股动脉。术后通过对皮瓣色泽质地的观察,了解皮瓣的血供情况;行彩色多普勒、数字减影血管造影检查和病理切片观察移植血管的通畅情况及细胞黏附情况。结果实验组皮瓣术后血运较好,对照组皮瓣术后肿胀坏死。彩色多普勒、数字减影血管造影检查显示,实验组移植术后1周有3只动物发生血管闭塞,另7只动物在术后4周血管仍通畅、无明显狭窄;对照组术后1周无1只动物血管通畅。实验组术后4周解剖移植血管,H-E染色显示脱细胞血管支架表面形成连续融合单层细胞,管腔无明显狭窄;对照组术后1周解剖移植血管可见血栓形成,H-E染色显示血管腔内表面缺乏细胞覆盖。结论CD34抗体修饰的脱细胞血管支架在早期抗凝及通畅率上均优于未经修饰的脱细胞血管支架。

Objective To evaluate the role of decellularized vascular scaffolds coated with anti-CD34 antibodies in capturing endothelial progenitor cells from the circulation to participate in recellularization.Methods Fresh caprine forelimb arteries were treated with repeated frozen/thawing,ultrahigh pressure and SDS to prepare decellularized vascular scaffolds.After reaction with photochemical crosslinker SANPAH,anti-rabbit CD34 was coated onto the decellularized vascular scaffolds using ultraviolet ray.Twenty New Zealand white rabbits were performed for right lower-abdominal pedicled skin flap,which were supplied by branches of femoral artery.Whole defects（1 cm） were made in femoral arteries and end-to-end anastomosis repaired by 10 cross-linked and 10 non-cross-linked scaffolds in experimental group and control group,respectively.The patency of the pedicle was observed through color and appearance of the flap postoperatively.After transplantation,patency rate and cell seeding were detected by Doppler,DSA,and pathological test.Results Flaps of the experimental group had good blood supply after transplantation,while swelling and necrosis could be found in the control group.Doppler and DSA showed that the 7 of 10 cross-linked scaffolds remained patent for 4 weeks and there was no stenonsis,but all the scaffolds were obstructed in the control group after 1 week.Hematoxylin and eosin staining revealed that the inner layers of cross-linked scaffolds were partly covered with endothelial cells four weeks later,and there was no noticeable stenosis.In contrast,thrombosis formation was noticed in the control group and there was no cell coverage one week after operation.Conclusion Cross-linked scaffolds with anti-CD34 antibodies are superior to bare scaffolds in early postoperative anticoagulation and patency.