Blood vessels were printed on a bioprinter

Anna Govorova, Infox.ru

Bioengineers from the University of California at San Diego managed to approach the solution of a very important problem in regenerative medicine - they were able to print a network of blood vessels on a 3D bioprinter, reports Infox.

This is a great achievement, because no organ can work without blood supply. And, if scientists have already learned how to grow some organoids and tissues from stem cells (this is the intestine, stomach, liver, heart, lung, retina and cornea of the eye, even a tiny brain), then the question of how to supply these organs with blood vessels remains open. At the same time, this is very important, because regenerative medicine aims to ensure that in the future organs grown from stem cells or printed on a bioprinter can be transplanted to a person.

In their current study, American bioengineers decided to take up the cultivation of vessels using 3D bioprinting technology. Bioprinting is a direction that is now actively developing around the world. There are several large corporations that develop bioprinters and printing technologies. We have already learned well how to print cartilage and bone tissues, which are successfully used in clinical practice, while, of course, not very widely.

As the head of the current study, Professor Shaochen Chen, explains, they used two types of material as a printing material: liquid polymers for printing the vascular framework and living cells (induced pluripotent stem cells, iPSC), which formed the inner lining layer of the vessels – the endothelium. The use of iPSC here is justified for many reasons, the authors explain. First of all, since these cells are obtained from the skin cells of the patients themselves, there should be no problems with rejection and immune response during further transplantation.

After the scientists prepared the material for printing, they created a model of what they were going to print using a computer program. And then the bioprinter layer by layer began to print vessels, distributing polymers and living cells in the right way.

A model of a network of blood vessels that was embedded in a 3D bioprinter
(pictures from the UC San Diego press release How 3D printing could save lives – VM).

Surprisingly, the printing was very fast – the whole process took no more than a few seconds.

3D bioprinter created by Professor Chen's group.

To test how the printed vessels would work, they were implanted into mice. Two weeks later, scientists were able to observe how the vessels took root and began to unite with the network of blood vessels of the animals themselves.

This is a good result, the authors say. However, they admit that another important task remains unresolved: implanted vessels cannot perform their main functions – the transport of nutrients and waste disposal.

The ultimate goal of our research and dream, says Professor Chen, is to introduce the method of printing vessels into clinical practice, but it is still a matter of the distant future. In the meantime, it is realistic to talk about the beginning of clinical trials, but this may happen only in a few years.

The authors report on the results of their work in the latest issue of the journal Biomaterials (Direct 3D bioprinting of prevascularized tissue constructs with complex microarchitecture).

Portal "Eternal youth" http://vechnayamolodost.ru  07.03.2017