480 Biomedical, Inc., Watertown, Massachusetts 02472, USA.
Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Nat Mater. 2018 Jan;17(1):96-103. doi: 10.1038/nmat5016. Epub 2017 Nov 20.
Implants for the treatment of tissue defects should mimic the mechanical properties of the native tissue of interest and should be resorbable as well as biocompatible. In this work, we developed a scaffold from variants of poly(glycolic) acid which were braided and coated with an elastomer of poly(glycolide-co-caprolactone) and crosslinked. The coating of the scaffold with the elastomer led to higher mechanical strength in terms of compression, expansion and elasticity compared to braids without the elastomer coating. These composite scaffolds were found to have expansion properties similar to metallic stents, utilizing materials which are typically much weaker than metal. We optimized the mechanical properties of the implant by tuning the elastomer branching structure, crosslink density, and molecular weight. The scaffolds were shown to be highly resorbable following implantation in a porcine femoral artery. Biocompatibility was studied in vivo in an ovine model by implanting the scaffolds into femoral arteries. The scaffolds were able to support an expanded open lumen over 12 months in vivo and also fully resorbed by 18 months in the ovine model.
用于治疗组织缺损的植入物应模拟感兴趣的天然组织的机械性能，并且应该可吸收且生物相容。在这项工作中，我们开发了一种由聚（乙醇酸）变体构成的支架，这些变体经过编织并涂覆有聚（乙交酯-己内酯）弹性体并交联。与没有弹性体涂层的编织物相比，支架的弹性体涂层导致压缩、扩展和弹性方面的机械强度更高。这些复合支架具有类似于金属支架的扩展特性，所用材料的强度通常远低于金属。我们通过调整弹性体支化结构、交联密度和分子量来优化植入物的机械性能。在猪股动脉中植入支架后，支架表现出高度的可吸收性。通过将支架植入羊股动脉，在体内研究了生物相容性。在体内 12 个月内，支架能够支撑扩张的开放管腔，并且在绵羊模型中在 18 个月内完全吸收。
