Sugiura Tadahisa, Tara Shuhei, Nakayama Hidetaka, Kurobe Hirotsugu, Yi Tai, Lee Yong-Ung, Lee Avione Y, Breuer Christopher K, Shinoka Toshiharu
Tissue Engineering Program and Surgical Research, Nationwide Children's Hospital, Columbus, Ohio.
QOL Research Center Laboratory, Gunze Limited, Ayabe-shi, Kyoto, Japan.
Ann Thorac Surg. 2016 Sep;102(3):720-727. doi: 10.1016/j.athoracsur.2016.01.110. Epub 2016 May 4.
Current commercialized small-diameter arterial grafts have not shown clinical effectiveness due to their poor patency rates. The present study evaluated the feasibility of an arterial bioresorbable vascular graft, which has a porous sponge-type scaffold, as a small-diameter arterial conduit.
The grafts were constructed by a 50:50 poly (1-lactic-co-ε-caprolactone) copolymer (PLCL) scaffold reinforced by a poly (1-lactic acid) (PLA) nanofiber. The pore size of the PLCL scaffold was adjusted to a small size (12.8 ± 1.85 μm) or a large size (28.5 ± 5.25 μm). We compared the difference in cellular infiltration, followed by tissue remodeling, between the groups. The grafts were implanted in 8- to 10-week-old female mice (n = 15 in each group) as infrarenal aortic interposition conduits. Animals were monitored for 8 weeks and euthanized to evaluate neotissue formation.
No aneurysmal change or graft rupture was observed in either group. Histologic assessment demonstrated favorable cell infiltration into scaffolds, neointimal formation with endothelialization, smooth muscle cell proliferation, and elastin deposition in both groups. No significant difference was observed between the groups. Immunohistochemical characterization with anti-F4/80 antibody demonstrated that macrophage infiltration into the grafts occurred in both groups. Staining for M1 and M2, which are the two major macrophage phenotypes, showed no significant difference between groups.
Our novel bioresorbable vascular grafts showed well-organized neointimal formation in the high-pressure arterial circulation environment. The large-pore scaffold did not improve cellular infiltration and neotissue formation compared with the small-pore scaffold.
目前商业化的小口径动脉移植物由于通畅率低，尚未显示出临床有效性。本研究评估了一种具有多孔海绵型支架的动脉生物可吸收血管移植物作为小口径动脉导管的可行性。
移植物由50:50的聚（1-乳酸-共-ε-己内酯）共聚物（PLCL）支架构建而成，该支架由聚（1-乳酸）（PLA）纳米纤维增强。将PLCL支架的孔径调整为小尺寸（12.8±1.85μm）或大尺寸（28.5±5.25μm）。我们比较了两组之间细胞浸润以及随后组织重塑的差异。将移植物作为肾下腹主动脉间置导管植入8至10周龄的雌性小鼠体内（每组n = 15）。对动物进行8周的监测，然后实施安乐死以评估新组织形成情况。
两组均未观察到动脉瘤样改变或移植物破裂。组织学评估显示，两组支架内均有良好的细胞浸润、伴有内皮化的新生内膜形成、平滑肌细胞增殖和弹性蛋白沉积。两组之间未观察到显著差异。用抗F4/80抗体进行的免疫组织化学表征表明，两组移植物中均有巨噬细胞浸润。对两种主要巨噬细胞表型M1和M2的染色显示，两组之间无显著差异。
我们的新型生物可吸收血管移植物在高压动脉循环环境中显示出组织良好的新生内膜形成。与小孔径支架相比，大孔径支架并未改善细胞浸润和新组织形成。
