Development of biomimetic thermoplastic polyurethane/fibroin small‐diameter vascular grafts via a novel electrospinning approach

Abstract

A new electrospinning approach for fabricating vascular grafts with a layered, circumferentially aligned, and micro-wavy fibrous structure similar to natural elastic tissues has been developed. The customized electrospinning collector was able to generate wavy fibers using the dynamic "jump rope" collecting process, which also solved the sample removal problem for mandrel-type collectors. In this study, natural silk fibroin and synthetic thermoplastic polyurethane (TPU) were combined at different weight ratios to produce hybrid small-diameter vascular grafts. The purpose of combining these two materials was to leverage the bioactivity and tunable mechanical properties of these natural and synthetic materials. Results showed that the electrospun fiber morphology was highly influenced by the material compositions and solvents employed. All of the TPU/fibroin hybrid grafts had mechanical properties comparable to natural blood vessels. The circumferentially aligned and wavy biomimetic configuration provided the grafts with a sufficient toe region and the capacity for long-term usage under repeated dilatation and contraction. Cell culture tests with human endothelial cells (EC) also revealed high cell viability and good biocompatibility for these grafts. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 985-996, 2018.

Fabrication and modification of wavy multicomponent vascular grafts with biomimetic mechanical properties, antithrombogenicity, and enhanced endothelial cell affinity

“…To achieve this property, a special design for the wavy inner layer was proposed in this study. We recently demonstrated that this wavy structure can mimic the biological configuration of native blood vessels and provide a “toe region” in single‐layered SDVGs . In this study, their performance was further enhanced by using multiple materials with properties similar to the components in native blood vessels.…”

“…We recently demonstrated that this wavy structure can mimic the biological configuration of native blood vessels and provide a "toe region" in single-layered SDVGs. 29,30 In this study, their performance was further enhanced by using multiple materials with properties similar to the components in native blood vessels. As illustrated in Figure 3(G), at low pressure, the wavy silk/PLA fibers oriented and aligned in the same fashion as collagen in blood vessels.…”

“…Biodegradable elastic thermoplastic polyurethane (TPU) with a molecular weight of 80,000 g/mol was synthesized using polyether–polyester copolymer as the soft segment following the procedure reported in our previous study . Solid silk fibroin was extracted from the cocoons of Bombyx mori silkworms following a procedure we previously described . All other chemicals and solvents were purchased from Sigma–Aldrich.…”

“…28 Solid silk fibroin was extracted from the cocoons of Bombyx mori silkworms following a procedure we previously described. 29 All other chemicals and solvents were purchased from Sigma-Aldrich. Milli-Q DI water was used throughout the experiment.…”

Effect of different emitter types on the production of nanofibrous tubular structures: Thickness uniformity and productivity

“…Besides planar nanofibrous layers, various structures prepared from nanofibers are being used as well. Example of these structures are tubes, that find applications mostly as vascular replacements [1][2][3][4][5][6] because electrostatic spinning allows the direct preparation of grafts of less than 6 mm in diameter which is very hard to achieve by common methods. Other potential application is their use as scaffolds for vascular tissue regeneration.…”