Department of Surgery and the Interdepartmental Program in Vascular Biology & Therapeutics, Yale University School of Medicine, New Haven, Connecticut, United States of America.
PLoS One. 2012;7(6):e38844. doi: 10.1371/journal.pone.0038844. Epub 2012 Jun 13.
Pericardial patches are commonly used in vascular surgery to close arteriotomies. The mechanism of early healing after patch implantation is still not well defined. We used a rat aortic patch model to assess pericardial patch healing and examined Ephrin-B2, a marker of arterial identity, expression within the post-implantation patch. We also determined whether endothelial progenitor cells (EPC) are associated with early patch healing in the arterial environment.
Wistar rats (200-250 grams) underwent infrarenal aortic arteriotomy and then closure via bovine or porcine pericardial patch angioplasty. Control groups included subcutaneously implanted patches. Patches were harvested at 0-30 days and analyzed by histology, immunohistochemistry, immunofluorescence and Western blot as well as quantitative PCR.
Prior to implantation, pericardial patches are largely composed of collagen and are acellular. Following arterial implantation, increasing numbers of CD68-positive cells as well as Ephrin-B2 and CD34 dual-positive cells are found within both bovine and porcine pericardial patches, whereas the infiltrating cells are negative for vWF and α-actin. Porcine patches have a luminal monolayer of cells at day 7, compared to bovine patches that have fewer luminal cells. Subcutaneously implanted patches do not attract Ephrin-B2/CD34-positive cells. By day 30, both bovine and porcine pericardial patches develop a neointima that contains Ephrin-B2, CD34, and VEGFR2-positive cells.
Both CD68-positive and Ephrin-B2 and CD34 dual-positive cells infiltrate the pericardial patch early after implantation. Arteriotomy closure via pericardial patch angioplasty shows patch adaptation to the arterial environment that may involve a foreign body response as well as localization of EPC. Arterial remodeling of pericardial patches support endothelialization and may represent a paradigm of healing of scaffolds used for tissue engineering.
心包补片在血管外科中常用于闭合血管切口。然而，补片植入后早期愈合的机制仍不清楚。本研究使用大鼠主动脉补片模型评估心包补片愈合情况，并检测植入后补片中动脉标志物 Ephrin-B2 的表达。我们还确定内皮祖细胞（EPC）是否与动脉环境中的早期补片愈合有关。
Wistar 大鼠（200-250 克）接受肾下主动脉切开术，然后通过牛心包或猪心包补片血管成形术进行闭合。对照组包括皮下植入的补片。在 0-30 天内采集补片，进行组织学、免疫组织化学、免疫荧光和 Western blot 以及定量 PCR 分析。
在植入之前，心包补片主要由胶原组成且无细胞。在动脉植入后，牛心包和猪心包补片中可见越来越多的 CD68 阳性细胞以及 Ephrin-B2 和 CD34 双阳性细胞，而这些浸润细胞不表达 vWF 和 α-actin。第 7 天，猪心包补片出现管腔单层细胞，而牛心包补片的管腔细胞较少。皮下植入的补片不会吸引 Ephrin-B2/CD34 阳性细胞。第 30 天，牛心包和猪心包补片均形成含有 Ephrin-B2、CD34 和 VEGFR2 阳性细胞的新生内膜。
在植入后早期，CD68 阳性细胞和 Ephrin-B2 和 CD34 双阳性细胞浸润心包补片。心包补片血管成形术闭合动脉切开术显示补片适应动脉环境，这可能涉及异物反应以及 EPC 的定位。心包补片的动脉重塑支持内皮化，可能代表用于组织工程的支架愈合的范例。
