Researchers develop two-layered artificial blood vessels

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Cross of a human artery Credit: Wikimedia commons
Cross of a human artery Credit: Wikimedia commons

Blocked arteries are a cause of major concern, and may lead to death by coronary (heart) artery disease or severe pain and disability in peripheral artery disease, in which arteries of legs are blocked. In invasive strategies, healthy vessels from another part of the patient’s body are used as grafts to bypass blocked arteries in coronary and peripheral artery disease.

More recently, synthetic grafts made from various polymers have also been explored as an alternative. In a recent article, a team of researchers have bioengineered blood vessels from stem cells to be used as grafts in vascular disease.

In this study, Zhou and his team successfully bioengineered two-layered small-diameter blood vessels by differentiating human stem cells into smooth muscle cells (SMCs) and endothelial cells (ECs) and growing them on polymer scaffolds. A polymeric mesh was prepared by electrospinning a mixture of polycaprolactone and gelatin into thin fibers. Differentiated SMCs, that form the wall of the artery, were seeded onto this mesh in a tubular shape. Once the cells had grown into a tube-like shape and the polymeric mesh had degraded, ECs, which line the inner wall of blood vessels, were deposited in the lumen of the SMC “tube” to form artificial blood vessels.

Blood vessels-3D rendering. 3D rendering of a 1 cubic millimeter portion of mouse brain cortex. Blood vessels staining Credit: Wikimedia commons
Blood vessels-3D rendering.
3D rendering of a 1 cubic millimeter portion of mouse brain cortex. Blood vessels staining Credit: Wikimedia commons

Authors claim that the bio-mechanical properties of the artificial blood vessels made in their lab, were similar to those of human blood vessels. These bioengineered blood vessels may avoid the undesired risk of secondary site injury with autologous grafts, as well as overcome limitations of polymeric grafts such as lack of biocompatibility.

However, the vessels engineered in this study also come with some limitations, such as the long time required to prepare them (8-12 weeks), cost, and requirement of delicate handling during storage or transport. Further testing in animals will reveal how these vessels perform in vivo and whether they are feasible to be used in bypass surgeries.

Read more here: http://www.nature.com/articles/srep35422