Artificial organ transplantation will become a common practice in 10 years

How to create a printed organ
Russian researchers intend to print thyroid gland on 3D bioprinter

Ksenia Kolesnikova, Rossiyskaya Gazeta

What "spare parts" for a person may appear in the near future? Liver and kidney factories – fiction or reality? What are the prospects for regenerative medicine? For an answer to these questions, the correspondent of "RG" went to the laboratory of the Research Institute of Molecular Medicine of the First Moscow State Medical University named after I.M. Sechenov.

In the "clean block" of the laboratory of the Department of Biomedical Research – complete sterility. You can get here only in a special suit, after several stages of processing and sterilization. It is necessary to observe how experiments are conducted through thick glass. A researcher at the microscope. The focus is on a tablet with six compartments, each of which contains a liquid nutrient medium for stem cells.

– These red drops can become part of a bioengineered organ, – Mikhail Krasheninnikov, a senior researcher at the department, explains to me.

It shows something resembling a colorless jellyfish.

– This is the rat liver, from which we "washed" all living cells, – Mikhail explains. – Only a protein tissue framework, resembling an organ in shape, remains. It is into it that we will populate the cells of another individual (to which the liver will be transplanted), "growing" now in the laboratory. This will avoid rejection of a foreign body.

Skin, bones, vessels, muscles, trachea, ear and even kidney, liver, heart – all this has already been created in laboratories in different countries. But most of the artificial organs are not yet able to fully work and are tested only on animals. For example, researchers from the University of Texas decided to grow lungs in this way, and scientists from Harvard University transplanted a bioengineered kidney to a rat. But it didn't function as efficiently as the natural original.

The technology is not yet perfect, experts emphasize. It is important that stem cells "understand" where they should develop depending on their position in the framework. The right direction for their growth is created by the nutrient medium where the workpiece is placed. It is important that the cells do not turn, for example, into cancerous tumors. Another problem is a full–fledged circulatory system in artificial organs, which is very difficult to reproduce.

Nevertheless, specialists have already learned how to make relatively simple "spare parts" for a person. For example, in the First honey, a tissue-engineered urethra was created and successfully transplanted to the patient in laboratory conditions. The cadaveric artery, cleared of cells, served as a framework for it, which took root perfectly.

There are successes in 3D bioprinting. But in the next 2-3 years, organ printing factories should not be expected

– According to the same principle, this year we performed a trachea transplant to a rabbit, but we went further. As a frame, not donor organs were used, but a completely artificial base," says Mikhail Krasheninnikov and shows a soft transparent sponge. – The recovered silk turned out to be a plastic and porous material, but the web is also used for these purposes. The rabbit's own cells isolated from the bone marrow were "sown" on it. Then this structure was treated in a special way and placed in a bioreactor, where the cells were attached to the frame. The animal's body did not reject such a trachea, and the transplanted organ began to adapt to new conditions.

The prospects of using this technology are huge: treatment of burns, bone fractures, diseases of articular cartilage, liver damage. For example, if a person's hand is burned, it will be possible to put on a glove soaked in his own cells. Gradually, the frame will dissolve, and the new skin formed from the applied cells will remain. If a leg is broken, you can put an artificial frame in which there will be cells aimed at forming bone and cartilage tissues.

Similar experiments have already been carried out on mice: a part of the foot grew in the animal in two weeks. And this technology is already close enough to be used in medical practice: next year, at the First Sechenov Moscow State Medical University, they want to present tissue-engineered cartilage that can be transplanted to a person.

Scientists are confident that the transplantation of organs created in the laboratory will enter into everyday practice in 10 years, and 3D printing technology will play a significant role in this. For example, Russian researchers – residents of Skolkovo – promise to print a thyroid gland on a bioprinter by mid-March.

– Why the thyroid gland? This is a fairly simple organ: on the one hand – the arterial entrance, on the other – the venous exit, between them - tissue from cells. The most difficult thing is to prove that it works on a living organism, the same rat," said the scientific director of the laboratory of biotechnological research, Professor Vladimir Mironov. – To plant a printed organ for her, we will expose the animal to radioactive radiation. After that, the level of hormones in the body will drop. Then we will transplant the structure we have recreated. And if the hormone levels recover, it will be possible to celebrate a breakthrough.

In medicine, 3D printing is mainly used for the manufacture of prostheses. In Holland, an elderly woman was implanted with a titanium jaw created on a printer, and in China, a 3D vertebra was inserted into a teenager. The next stage – bioprinting – already allows you to reproduce cartilage tissues, skin and blood vessels. American scientists even managed to create with the help of a 3D bioprinter a semblance of an artificial liver that functioned for 40 days.

The cost of bioprinters varies depending on the model: from 250 thousand dollars to a million. But how does bioprinting differ from 3D prostheses and tissue-engineered structures? Adipose tissue is taken from the patient, from which stem cells are isolated. Then they are reprogrammed into the cell types needed to create the organ. Biochernils – spheroids are made of them. These are micron-sized balls containing up to 10 thousand living cells of the required type. Next, the printer places them in the base – a thick layer of hydrogel. Thus, the living tissue is created immediately, and not formed on the frame.

But before you start printing, you need to create a 3D model of the organ: virtually cut it into layers, set the distribution of cells of different types in them, provide for the placement of cavities inside the spheroids from which vessels are formed. The result is a tissue sample consisting of layers of cells and a hydrogel. This sample is placed in a special bioreactor, where the organ "matures": the spheroids fuse with each other, forming a tight bond, and the hydrogel self-destructs.

– Organs can be divided into four groups according to the complexity of printing: flat – for example, skin, hollow tubular – vessels or urethra, hollow non–tubular – bladder or uterus, and solid organs - for example, liver or kidney. Certain successes in 3D bioprinting have been achieved in the first two groups: preclinical animal tests were conducted in the USA to replace skin defects, as well as animal tests using a printed vessel in Japan," says Professor Andrey Vinarov, Deputy director of the Research Institute of Uronephrology and Human Reproductive Health of the First Moscow State Medical University. Sechenov. – Any bioengineering technology must pass serious preclinical tests. There are a huge number of difficulties that may arise, including regulatory ones. So it is premature to talk about the supply of organ seals to the stream.

The law on the circulation of biomedical cell products, which has been discussed for several years, has not yet been adopted. In addition, in order to put the creation of artificial organs on stream, it will be necessary to amend the law on transplantation – after all, only related transplantation and transplantation from a cadaver donor appear there.

Today, any operation using artificially created bioengineered structures is carried out only with the approval of the independent ethics committee and the academic council of the university. In addition, the permission of the patient, his relatives and a considerable amount of insurance is required. So in the next 2-3 years, organ printing factories should not be expected. And what will happen in 10 years depends on the legislative framework and administrative decisions, according to the First Honey: there are scientists, doctors and equipment to "put the bioengineering industry on its feet."

Help "RG"
The lack of donor organs is one of the main problems of Russian transplantology. According to the Ministry of Health, over the past seven years in Russia organ donation has doubled and amounted to 1,400 operations per year. However, 9 thousand transplants need to be carried out annually. In addition, organ transplants are carried out only in 22 regions of Russia.

Portal "Eternal youth" http://vechnayamolodost.ru21.11.2014