Yokota Takenori, Ichikawa Hajime, Matsumiya Goro, Kuratani Toru, Sakaguchi Taichi, Iwai Shigemitsu, Shirakawa Yukitoshi, Torikai Kei, Saito Atsuhiro, Uchimura Eiichiro, Kawaguchi Naomasa, Matsuura Nariaki, Sawa Yoshiki
Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine, Osaka, Japan.
J Thorac Cardiovasc Surg. 2008 Oct;136(4):900-7. doi: 10.1016/j.jtcvs.2008.02.058. Epub 2008 Jul 3.
Various types of natural and synthetic scaffolds with arterial tissue cells or differentiated stem cells have recently attracted interest as potential small-caliber vascular grafts. It was thought that the synthetic graft with the potential to promote autologous tissue regeneration without any seeding would be more practical than a seeded graft. In this study, we investigated in situ tissue regeneration in small-diameter arteries using a novel tissue-engineered biodegradable vascular graft that did not require ex vivo cell seeding.
Small-caliber vascular grafts (4 mm in diameter) were fabricated by compounding a collagen microsponge with a biodegradable woven polymer tube that was constructed in a plain weave pattern with a double layer of polyglycolic acid (core) and poly-L-lactic acid (sheath) fibers. We implanted these tissue-engineered vascular grafts bilaterally into the carotid arteries of mongrel dogs (body weight, 20-25 kg). No anticoagulation regimen was used after implantation. We sacrificed the dogs 2, 4, 6, and 12 months (n = 4 in each group) after implantation and evaluated the explants histologically and biochemically.
All of the tissue-engineered vascular grafts were patent with no signs of thrombosis or aneurysm at any time. Histologic and biochemical examinations showed excellent in situ tissue regeneration with an endothelial cell monolayer, smooth muscle cells, and a reconstructed vessel wall with elastin and collagen fibers.
Our study indicated that this novel tissue-engineered vascular graft promoted in situ tissue regeneration and did not require ex vivo cell seeding, thereby conferring better patency on small-caliber vascular prostheses.
各种带有动脉组织细胞或分化干细胞的天然和合成支架，近来作为潜在的小口径血管移植物受到关注。人们认为，具有促进自体组织再生潜力且无需任何接种的合成移植物，会比接种后的移植物更实用。在本研究中，我们使用一种新型的无需体外细胞接种的组织工程可生物降解血管移植物，研究了小直径动脉的原位组织再生情况。
通过将胶原微海绵与一种可生物降解的编织聚合物管复合，制备小口径血管移植物（直径4毫米），该聚合物管采用平纹编织图案，由双层聚乙醇酸（芯）和聚-L-乳酸（鞘）纤维构成。我们将这些组织工程血管移植物双侧植入杂种犬（体重20 - 25千克）的颈动脉。植入后未使用抗凝方案。在植入后2、4、6和12个月处死犬（每组n = 4），并对取出的移植物进行组织学和生化评估。
所有组织工程血管移植物在任何时候均保持通畅，无血栓形成或动脉瘤迹象。组织学和生化检查显示原位组织再生良好，有内皮细胞单层、平滑肌细胞以及带有弹性蛋白和胶原纤维的重建血管壁。
我们的研究表明，这种新型组织工程血管移植物促进了原位组织再生，且无需体外细胞接种，从而使小口径血管假体具有更好的通畅性。
