A new material for creating artificial vessels
Researchers at the Vienna University of Technology and the Vienna Medical University have developed artificial blood vessels made of a new elastic material, which is gradually replaced by a new tissue in the conditions of the body. Eventually, new fully functional blood vessels are formed in place of such polymer structures.
Atherosclerosis-induced disorders of the functioning of blood vessels are the most common cause of death in industrialized countries. Very often in such situations, the only way out is surgical replacement of the affected areas with vessels removed from other parts of the patient's body.
Earlier attempts to replace such transplants with polymer prostheses were not very successful mainly due to the poor compatibility of artificial materials with body tissues. Such grafts, especially those with a small diameter, were very easily clogged with blood clots.
To solve this problem, the authors have developed a new class of polymer materials, called thermoplastic polyurethanes.
In the process of creating vascular prostheses from a polymer solution, thin fibers are spun in an electric field, which are subsequently wound onto a coil-frame. The result is a vessel whose wall consists of an elastic polymer material.
Transplantation of such vessels has demonstrated very good results in experiments on rats. The study of the interaction of the graft and blood using mass spectrometry showed that the pores initially present in the polymer wall of the vessel pass a small amount of blood, ensuring saturation of the wall with growth factors and attracting endogenous cells. Analysis of the condition of the transplanted vessels 6 months after surgery revealed no aneurysms, as well as signs of thrombosis and inflammation. Moreover, endogenous cells attracted by growth factors colonized the prosthesis material and gradually replaced it with living tissue.
On the left – a tube made of porous polyurethane, on the right – a blood vessel formed from it
(collage from an article in Acta Biomaterialia).
According to the authors, in fact, the new vascular wall was formed much faster than expected, so the degradation period of polymer tubes can be shortened. They are currently working on improving the properties of the polymer.
Before the start of clinical studies of the developed approach, scientists will have to carry out several more preclinical works. However, the results obtained to date give them confidence that the new method will be introduced into clinical practice in the coming years.
Article by Helga Bergmeister et al. Biodegradable, thermoplastic polyurethane grafts for small diameter vascular replacements is published in the journal Acta Biomaterialia.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of Vienna Medical University:
New material for creating artificial blood vessels.
06.05.2015