Vessels in reserve
Semi-finished vessels have learned to grow from donor cells
CNewsR&D based on ScienceNOW: Off-the-Shelf Blood VesselsSemi-finished vessels grown with the help of donor cells can solve the problem of the lack of transplants, which doctors often face when various surgical interventions are necessary.
Blood vessel transplantation is necessary during aorto-coronary bypass surgery and in a number of other cases. Usually doctors remove veins for transplantation from the legs or other parts of the patient's body. Unfortunately, this is not always possible, and the use of donor tissues and animal tissues for these purposes is unsafe and inefficient. In search of a solution to the problem, some researchers grow layers of the patient's own cells in the laboratory and fold them into the likeness of blood vessels. However, this procedure is very expensive and takes up to 9 months, which exceeds the expectations of many patients.
A finished vessel grown using donor smooth muscle cells
Researchers of the biotechnological company Humacyte, based in Morrisville, North Carolina, have proposed a fundamentally new approach to the creation of blood vessel transplants (Shannon L.M. Dahl et al., Readily Available Tissue-Engineered Vascular Grafts // Science Translational Medicine, Vol. 3, Issue 68, p. 68 – VM).
They have developed a method for growing smooth muscle cells of dead donors on tubular scaffolds made of a biodegradable polyglycolic acid polymer. As the culture grows, the cells completely cover the surface of the skeleton, and the collagen and extracellular matrix proteins produced by them gradually replace the decomposing polyglycolic acid. After some time, the cells are removed with a special detergent, and the remaining cell-free vessel can theoretically be stored for several months and should not cause an immune rejection reaction during transplantation.
Comparison of the properties, including strength, of vessels grown from cells of one donor and from a mixture of cells of several donors revealed no differences. This fact made the researchers very happy, since the use of a mixture of cells will increase the number of vessels grown in one batch, and, accordingly, will significantly reduce the cost of the process.
When transplanted into the upper limbs of eight baboon monkeys, artificial vessels retained functionality and patency for at least six months. They also did not cause the development of rejection reactions, despite the fact that they consisted of human collagen and extracellular matrix proteins. Transplantation of similar vessels grown using dog cells to five dogs who underwent aorto-coronary bypass surgery also showed good results that persisted for at least one year. In both models, new vessels were populated with cells of various types forming the tissues of normal blood vessels, which indicates a good survival rate of transplants.
Despite the small number of animals used in the experiments, the authors consider the results to be very promising. They are currently preparing the ground for clinical trials.
Portal "Eternal youth" http://vechnayamolodost.ru04.02.2011