Researchers at the University of Sydney in Australia have developed an electrospun blood vessel replacement. The material contains tropoelastin, a natural precursor for elastin, a key component of blood vessel walls. Elastin is present in concentric circles in natural blood vessels and provides the elastic properties which allow them to distend slightly and then reform their original shape in response to changes in blood flow and blood pressure. This latest construct allows similar layers of elastin to form when implanted into the body, and over time the grafted vessel appears to develop into something approaching a functional blood vessel. The researchers hope that the technology will provide off-the-shelf solutions for blood vessel transplants. Diseased blood vessels sometimes need to be replaced, but at present there are no reliable blood vessel replacements that fully mimic their natural counterparts. Synthetic materials are sometimes used in surgical implants that are intended to replace vessels, but these do not grow and mature with the patient, and will typically need to be replaced several times as pediatric patients grow. The researchers behind this latest technology hope to change things. They report that their new vessel constructs should grow and mature in the body, and they have claim to have shown the most sophistication and complexity in mimicking natural vessels than previously reported vessel replacement technologies. “Nature converts this manufactured tube over time to one that looks, behaves and functions like a real blood vessel,” said Anthony Weiss, a researcher involved in the study. “The technology’s ability to recreate the complex structure of biological tissues shows it has the potential to not only manufacture blood vessels to assist in surgery, but also sets the scene for the future creation of other synthetic tissues such as heart valves.” The engineered vessel constructs were created using electrospinning, which is a way to create and deposit ultrafine fibers through a needle in such a way that they solidify together to form a coherent structure. The spun structure contains tropoelastin fibers, which are a natural elastin precursor that cells use to create elastin. These fibers are embedded in a polyglycerol sebacate matrix, which is a biodegradable biomaterial. When implanted into animals, the new constructs appear to allow structures to develop that are naturally found in blood vessels, such as the concentric elastin rings that give the vessels their elastic properties. The researchers hope that this will translate to better therapeutic outcomes in human patients. “Currently when kids suffer from an abnormal vessel, surgeons have no choice but to use synthetic vessels that function well for a short time but inevitably children need additional surgeries as they grow,” said Christopher Breuer, another researcher involved in the study. “This new technology provides the exciting foundation for the manufactured blood vessels that to continue to grow and develop over time.” Top image: Artist’s representation of the ‘living blood vessel’. Credit: Designed by Ziyu Wang and illustrated by Ella Maru Studio Source
