Development of a vascular substitute produced by weaving yarn made from human amniotic membrane

Abstract

Because synthetic vascular prostheses perform poorly in small-diameter revascularization, biological vascular substitutes are being developed as an alternative. Although their in vivo results are promising, their production involves long, complex, and expensive tissue engineering methods. To overcome these limitations, we propose an innovative approach that combines the human amniotic membrane (HAM), which is a widely available and cost-effective biological raw material, with a rapid and robust textile-inspired assembly strategy. Fetal membranes were collected after cesarean deliveries at term. Once isolated by dissection, HAM sheets were cut into ribbons that could be further processed by twisting into threads. Characterization of the HAM yarns (both ribbons and threads) showed that their physical and mechanical properties could be easily tuned. Since our clinical strategy will be to provide an off-the-shelf allogeneic implant, we studied the effects of decellularization and/or gamma sterilization on the histological, mechanical, and biological properties of HAM ribbons. Gamma irradiation of hydrated HAMs, with or without decellularization, did not interfere with the ability of the matrix to support endothelium formation in vitro. Finally, our HAM-based, woven tissue-engineered vascular grafts (TEVGs) exhibited clinically relevant mechanical properties. Thus, this study demonstrates that human, completely biological, allogeneic, small-diameter TEVGs can be produced from HAM, thereby avoiding costly cell culture and bioreactors.

Effects of weaving parameters on the properties of completely biological tissue-engineered vascular grafts

“…Mechanical mismatch between a vascular graft and the host artery is considered as an important cause of intimal hyperplasia, which is a major cause of graft failure [21,[23][24][25][26]39]. Our group recently published two studies in which TEVGs were woven either from CAM or human amniotic membrane threads [29,40]. Both grafts displayed burst pressure, suture retention strength, and transmural permeability that would support implantation, but would create a mechanical mismatch with native blood vessels.…”

“…Both grafts displayed burst pressure, suture retention strength, and transmural permeability that would support implantation, but would create a mechanical mismatch with native blood vessels. In the amniotic membrane study, high transmural permeability was reduced by using wider threads [40]. In the current study, we took advantage of the versatility of textile assembly to better understand how to control the overall properties of our woven CAM-based TEVG.…”

Current biofabrication methods for vascular tissue engineering and an introduction to biological textiles

“…This will allow evaluation of the effectiveness of the woven CAMbased TEVGs in a clinically relevant allogeneic context for long-term studies in large animals to justify translation to humans. A recent approach to produce human woven TEVG, which is more economical, uses biological yarns made from human amniotic membranes [98].…”

The cell-assembled extracellular matrix: A focus on the storage stability and terminal sterilization of this human “bio” material

“…Cross-section of CAM ribbons was evaluated as previously described with biaxial laser micrometer [ 15 ]. Then, ribbons extremities were clamped between the flat jaws of a tensile test apparatus (100N load cell, AGSX, Shimadzu), pre-loaded (to 0.05 N, 20 mm/min), and stretch (to breaking point, at a speed of 1% of sec of the initial length (L0) of the sample after preloading.…”