Melchiorri Anthony J, Hibino Narutoshi, Brandes Zachary R, Jonas Richard A, Fisher John P
Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742.
Department of Cardiovascular Surgery, Children's National Medical Center, Washington, DC 20010.
J Biomed Mater Res A. 2014 Jun;102(6):1972-1981. doi: 10.1002/jbm.a.34872. Epub 2013 Jul 30.
Adjusting the mechanical properties of polyester-based vascular grafts is crucial to achieving long-term success in vivo. Although previous studies using a fabric-based approach have achieved some success, a central issue with pure poly(lactic acid) (PLA) or poly(glycolic acid) (PGA) grafts sealed with poly(DL-caprolactone-co-lactic acid) (P(CL/LA)) has been stenosis. Intimal hyperplasia, a leading cause of stenosis, can be caused by the mechanical incompatibility of synthetic vascular grafts. Investigating the performance of poly(glycolic-co-lactic acid) (PGLA) grafts could lead to insight into whether graft stenosis stems from mechanical issues such as noncompliance and unfavorable degradation times. This could be achieved by examining grafts with tunable mechanical properties between the ranges of such properties in pure PGA and PLA-based grafts. In this study, we examined PGLA-based grafts sealed with different P(CL/LA) solutions to determine the PGLA-P(CL/LA) grafts' mechanical properties and tissue functionality. Cell attachment and proliferation on graft surfaces were also observed. For in vivo assessment, grafts were implanted in a mouse model. Mechanical properties and degradation times appeared adequate compared to recorded values of vessels used in autograft procedures. Initial neotissue formation was observed in the grafts and patency maintained during the pilot study. This study presents a ∼1-mm diameter degradable graft demonstrating suitable mechanical properties and in vivo pilot study success, enabling further investigation into the tuning of mechanical properties to reduce complications in degradable polyester fabric-based vascular grafts.
调整聚酯基血管移植物的机械性能对于在体内取得长期成功至关重要。尽管先前使用基于织物的方法的研究已取得了一些成功,但用聚(DL-己内酯-共-乳酸)(P(CL/LA))密封的纯聚乳酸(PLA)或聚乙醇酸(PGA)移植物的一个核心问题一直是狭窄。内膜增生是狭窄的主要原因,可能由合成血管移植物的机械不相容性引起。研究聚乙醇酸-共-乳酸(PGLA)移植物的性能可能有助于深入了解移植物狭窄是否源于诸如顺应性差和降解时间不利等机械问题。这可以通过检查在纯PGA和PLA基移植物的此类性能范围内具有可调机械性能的移植物来实现。在本研究中,我们检查了用不同P(CL/LA)溶液密封的基于PGLA的移植物,以确定PGLA-P(CL/LA)移植物的机械性能和组织功能。还观察了细胞在移植物表面的附着和增殖。为了进行体内评估,将移植物植入小鼠模型中。与自体移植手术中使用的血管的记录值相比,机械性能和降解时间似乎足够。在试点研究期间,观察到移植物中有初始新组织形成且保持了通畅。本研究展示了一种直径约1毫米的可降解移植物,其具有合适的机械性能且在体内试点研究中取得成功,这使得能够进一步研究调整机械性能以减少基于可降解聚酯织物的血管移植物中的并发症。