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一种高机械强度的可吸收复合高分子血管支架

 

 

Nat. mater, 2017, ####

 

 

美国480生物医药公司的MariaPalasis团队与哈佛大学及麻省理工学院的研究人员合作,共同在Nature Materials上发表了一篇标题为"The development of bioresorbable composite polymeric implants with high mechanical strength"的文章。

在这项工作中,研究人员从聚乙醇酸(PGA)衍生物出发,经编织后用乙交酯-己内酯共聚物(PGCL)覆盖其表面,再通过交联形成复合生物支架。覆盖在高强度PGA衍生物表面的高弹性PGCL橡胶赋予了该体系优异的机械强度。与未经PGCL橡胶包覆的生物支架相比,经PGCL橡胶包覆后的复合生物支架在拉伸、压缩、弹性等力学测试中表现出更优异的性能,尤其在拉伸性能方面能与金属复合生物支架媲美。通过调控PGCL橡胶的分支结构、交联密度和相对分子质量,研究人员进一步提高了该复合生物支架的机械性能。该生物支架在猪股动脉中能被充分吸收。通过将该复合生物支架植入绵羊股动脉,研究人员发现该复合生物支架能将血管撑开的状态维持12个月,并在18个月后被生物体完全吸收。

自膨胀特性和优异的力学性使该复合生物支架适用于生物体内的腔体和管道等软组织,高强度、高弹性及优异的生物兼容性等特点则使该生物支架尤其适用于动脉血管疾病的治疗。

 

 

 

Maria Palasis, a team of 480 biomedical companies in the United States, works with researchers from Harvard University and the Massachusetts institute of technology common in Nature Materials on published an article entitled "The development of bioresorbable comosite polymeric implants with high mechanical strength". In this work, they 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. they 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.

(张守燕)

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