Mechanical behavior of bilayered small-diameter nanofibrous structures as biomimetic vascular grafts

Abstract

a b s t r a c tTo these days, the production of a small diameter vascular graft (o6 mm) with an appropriate and permanent response is still challenging. The mismatch in the grafts mechanical properties is one of the principal causes of failure, therefore their complete mechanical characterization is fundamental. In this work the mechanical response of electrospun bilayered small-diameter vascular grafts made of two different bioresorbable synthetic polymers, segmented poly(ester urethane) and poly(L-lactic acid), that mimic the biomechanical characteristics of elastin and collagen is investigated. A J-shaped response when subjected to internal pressure was observed as a cause of the nanofibrous layered structure, and the materials used. Compliance values were in the order of natural coronary arteries and very close to the bypass gold standard-saphenous vein. The suture retention strength and burst pressure values were also in the range of natural vessels. Therefore, the bilayered vascular grafts presented here are very promising for future application as smalldiameter vessel replacements.

Biomechanical Remodeling of Biodegradable Small-Diameter Vascular Grafts in Situ

“…Сто-ит отметить, что несмотря на высокую жесткость, PCL-и PHBV/PCL-графты показали хорошую комплаентность относительно Dacron и ePTFE в сравнительном аспекте с v. saphena. На основании полученных результатов и данных литературы по вязкоэластическим свойствам графты были более приближены к v. saphena, a. mammaria и коронар-ным артериям человека, чем протезы из Dacron и ePTFE [8]. Возможно, что при применении PCL-и PHBV/PCL-графтов в качестве трехмерного каркаса с инкорпорированием клеток их комплаентность бу-дет более близкой к нативным сосудам в сравнении с экспериментами in vitro.…”

“…ст. ), r -внутренний радиус сосуда (мм), h -толщина стенки сосуда (мм) [8,9]. Биомеханическое моделирование.…”

Cell layer‐electrospun mesh composites for coronary artery bypass grafts

“…The combined requirement for high strength as well as high compliance (low modulus) under physiological loading conditions has proven challenging to meet with single component scaffolds . For instance, electrospun scaffolds based on nano‐ or micron‐scale fused‐fibers have a number of potential advantages in terms of arterial graft applications .…”

“…Circumferentially aligned fibers have the capacity not only to provide necessary circumferential strength but also to provide contact guidance, inducing cells to take on the circumferential orientation typical of smooth muscle cells (SMCs) within the arterial medial layer . That said, the modulus of electrospun mesh scaffolds at normal arterial stresses is generally significantly greater than the ≈200–400 kPa circumferential modulus of the coronary artery medial layer at physiological pressures . Therefore, a scaffold design that maintains the high tensile strength of an electrospun mesh, while bringing the compliance of the constructs nearer to that of native coronary artery would be desirable.…”

“…The combined requirement for high strength as well as high compliance (low modulus) under physiological loading conditions has proven challenging to meet with single component scaffolds. [9][10][11][12][13][14] For instance, electrospun scaffolds based on nano-or micron-scale fused-fibers have a number of potential advantages in terms of arterial graft applications. [15][16][17][18] In particular, the ability to control fiber alignment by tailoring spinning conditions can allow for circumferentially oriented fibers.…”