Why do scientists need hybrid organisms? Organ growing

Artificial human organs will soon be grown in a clinic under construction at the Kirov Military Medical Academy in St. Petersburg. The decision to build the clinic was made by the Minister of Defense. They plan to equip the multidisciplinary center with the most modern equipment, which will allow the most detailed study of stem cells. Scientific and technical department, which will deal cell technologies, has already been formed.

“The main direction of the department’s work will be the creation of a biological bank and the creation of opportunities for growing artificial organs,” says the head of the organization’s department scientific work and training of scientific and pedagogical personnel of the Academy Evgeniy Ivchenko. “Russian scientists have been working on artificial organs for a long time.”

Two years ago, the head of the Federal scientific center Transplantology and Artificial Organs named after Academician V.I. Shumakov Murat Shagidulin reported on the creation of an artificial analogue of the liver, suitable for transplantation. Scientists were able to obtain an artificial liver and test it in preclinical conditions. The organ was grown on the basis of an acellular framework of the liver, from which all tissue was previously removed using a special technology. Only the protein structures of the blood vessels and other organ components remained. The scaffold was seeded with autologous cells bone marrow and liver. Experiments on animals have shown: if the grown element was implanted into the liver or mesentery small intestine, it promoted tissue regeneration and gave full recovery functions of the damaged organ. The animals were models of acute and chronic liver failure. And the grown element made it possible to double the survival rate. A year after implantation, all animals were still alive. Meanwhile, in the control group, about 50% of the individuals died. Seven days after implantation in the main group, biochemical indicators of liver function were already at normal levels. After 90 days after transplantation into the mesentery of the small intestine, scientists found viable hepatocytes and new vessels that had grown through the element’s frame.

“Research into the creation of complex bioengineered organs such as the liver, kidneys, lungs and heart, in last years are being carried out in leading scientific laboratories in the USA and Japan, but they have not yet progressed beyond the stage of study on an animal model,” comments Murat Shagidulin, head of the department of experimental transplantology and artificial organs of the Center. - Our experiments on animals went well. Three months after transplantation, they found in the bodies of the animals healthy cells liver and new blood vessels. This indicated that the regeneration process of the transplanted liver was taking place and that it had taken root.”

Japanese scientists from the University of Yokohama managed to grow a liver several millimeters in size. They were able to do this thanks to induced pluripotent stem cells (iPSCs). The grown liver functions as a full-fledged organ. According to the head of the research group, Professor Hideki Taniguchi, the mini-liver copes with the processing harmful substances as effective as the real thing human organ. Scientists hope to start clinical trials artificial liver in 2019. New organs created in the laboratory will be transplanted into patients with severe liver diseases to maintain its normal functions.

Somewhat earlier, Japanese scientists in the laboratory almost came close to newest discovery- creation of fully functioning kidneys that can replace real ones. Before this, prototypes of an artificial kidney were created. But they were unable to excrete urine normally (they became swollen from pressure). However, the Japanese corrected the situation. Experts are already quite successfully transplanting artificial kidneys pigs and rats.
Dr. Takashi Yooko and his colleagues at Jinkei University School of Medicine used stem cells to not just grow kidney tissue, but to grow both a drainage tube and bladder. In turn, rats, and then pigs, were incubators in which embryonic tissue was already developing and growing. When a new kidney was connected to an existing one in the body of animals bladder, the system worked as a whole. Urine flowed from the transplanted kidney into the transplanted bladder, and only after that did it enter the animal’s bladder. As observations showed, the system worked eight weeks after transplantation.

According to scientists, in the future, it may be possible to create full-fledged vocal cord implants for people. Researchers collected tissue fragments four people suffering from problems with the vocal cords. These patients had their ligaments removed. Tissue was also collected from one deceased donor. Experts isolated, purified and grew mucosal cells in a special three-dimensional structure that mimics the environment of the human body. In about two weeks, the cells grew together and formed tissue that resembles real ones in elasticity and stickiness. vocal cords. Then specialists attached the resulting vocal cords to an artificial trachea and passed humidified air through them. When the air reached the ligaments, the tissues vibrated and produced a sound, as if it happened when normal conditions in organism. In the near future, doctors expect to consolidate the results obtained on people who need it.

The ability to grow a human organ in a test tube and transplant it into a person in need of a transplant is the dream of transplantologists. Scientists around the world are working on this and have already learned how to make tissues, small working copies of organs, and we are actually only a short distance away from full-fledged spare eyes, lungs and kidneys. So far, organelles are used mainly for scientific purposes; they are grown to understand how organs work and how diseases develop. But from this to transplantation there are only a few steps. MedNews has collected information about the most promising projects.

Lungs. Scientists from the University of Texas grew human lungs in a bioreactor. True, without blood vessels such lungs are not functional. However, a team of scientists from Medical center Columbia University Medical Center, New York recently obtained a functional lung with perfusion and healthy tissue for the first time in the world. vascular system in rodents ex vivo.

Heart muscle tissue. Bioengineers from the University of Michigan managed to grow a piece of muscle tissue. True, a heart made of such tissue will not be able to function fully yet; it is twice as weak as the original. However, this is the strongest sample of heart tissue yet.

Bones. Israeli biotech company Bonus BioGroup used 3D scans to create a gel-like scaffold of bone before seeding it with stem cells taken from fat. They successfully transplanted the resulting bones into rodents. Experiments are already being planned to grow human bones using the same technology.

Stomach tissue. Scientists led by James Wells from Children's Medical clinical center in Cincinnati (Ohio) managed to grow three-dimensional structures “in vitro” human stomach using embryonic stem cells and from adult pluripotent cells reprogrammed into stem cells. These structures turned out to be capable of producing all necessary for a person acids and digestive enzymes.

Japanese scientists grew an eye in a Petri dish. The artificially grown eye contained the main layers of the retina: pigment epithelium, photoreceptors, ganglion cells and others. It is not yet possible to transplant it entirely, but tissue transplantation is a very promising direction. Embryonic stem cells were used as the starting material.

Genentech scientists have grown a prostate from a single cell. Molecular biologists from California managed to grow an entire organ from a single cell.
Scientists managed to find the only powerful stem cell in prostatic tissue, which can grow into an entire organ. Such cells turned out to be slightly less than 1% of the total number. In the study, 97 mice were transplanted with such a cell under the kidney, and 14 of them grew a full-fledged prostate capable of functioning normally. Biologists found exactly the same population of cells in the human prostate, although at a concentration of only 0.2%.

Heart valves. Swiss scientists Dr. Simon Hoerstrup and Dorthe Schmidt from the University of Zurich were able to grow human heart valves using stem cells taken from amniotic fluid. Now doctors will be able to grow heart valves specifically for an unborn child if he has heart defects in his embryonic state.

Auricle. Using stem cells, scientists grew. The experiment was carried out by researchers from the University of Tokyo and Kyoto University under the direction of Thomas Cervantes.

Leather. Scientists from the University of Zurich (Switzerland) and the university children's hospital of this city for the first time managed to grow human skin in the laboratory, permeated with blood and lymphatic vessels. The resulting skin flap is able to almost completely perform the function healthy skin for burns, surgical defects or skin diseases.

Pancreas. Scientists have created for the first time capable of producing insulin. Another attempt to cure type I diabetes.

Kidneys. Scientists from the Australian University of Queensland have learned to grow artificial kidneys from skin stem cells. So far these are only small organoids measuring 1 cm, but in structure and functioning they are almost identical to the kidneys of an adult.

Medical scientist at work

For many years, scientists around the world have been working on creating working tissues and organs from cells. The most common practice is to grow new tissues from stem cells. This technology has been developed for many years and is consistently bringing success. But it is not yet possible to fully provide the required number of organs, since it is possible to grow an organ for a specific patient only from his stem cells.

Scientists from Great Britain have managed to do something that no one else has managed to do so far - to reprogram cells and grow them into a working organ. This will make it possible in the foreseeable future to provide organs for transplantation to everyone who needs it.

Growing organs from stem cells

Growing organs from stem cells has been familiar to doctors for a long time. Stem cells are the progenitors of all cells in the body. They can replace any damaged cells and are intended to restore the body. The maximum number of these cells occurs in children after birth, and with age their number decreases. Therefore, the body’s ability to heal itself gradually decreases.

The world has already created many fully functioning organs from stem cells; for example, in 2004 in Japan, capillaries and blood vessels were created from them. And in 2005, American scientists managed to create brain cells. Valves were created in Switzerland in 2006 human heart from stem cells. Also in 2006, liver tissue was created in Britain. Until today, scientists have dealt with almost all tissues of the body, even growing teeth.

A very interesting experiment was carried out in the USA - they grew a new heart on a frame from an old one. The donor heart was cleared of muscle and new muscles were grown from stem cells. This completely eliminates the possibility of donor organ rejection, since it becomes “our own.” By the way, there are suggestions that it will be possible to use a pig’s heart, which is anatomically very similar to a human’s, as a frame.

A new way to grow organs for transplantation (Video)

Main disadvantage existing method growing organs is a necessity for their production of the patient’s own stem cells. Not every patient can have stem cells, and especially not everyone has ready-made frozen cells. But recently, researchers from the University of Edinburgh managed to reprogram the body's cells in such a way that they allowed them to grow the necessary organs. According to forecasts wide application This technology will become possible in about 10 years.

The post-industrial pace of human development, namely science and technology, is so great that it was impossible to imagine it 100 years ago. What previously could only be read about in popular science fiction has now appeared in the real world.

21st century medicine is more advanced than ever. Diseases that were previously considered deadly are now being successfully treated. However, the problems of oncology, AIDS and many other diseases have not yet been solved. Fortunately, in the near future there will be a solution to these problems, one of which will be the cultivation of human organs.

Fundamentals of Bioengineering

Science, which uses the information basis of biology and uses analytical and synthetic methods to solve its problems, originated not so long ago. Unlike conventional engineering, which uses technical sciences, mostly mathematics and physics, for its activities, bioengineering goes further and uses innovative methods in the form of molecular biology.

One of the main tasks of the newly created scientific and technical sphere is the cultivation of artificial organs in laboratory conditions for the purpose of their further transplantation into the body of a patient whose organ has failed due to damage or wear and tear. Based on three-dimensional cellular structures, scientists have been able to make progress in studying the effects of various diseases and viruses on the functioning of human organs.

Unfortunately, these are not full-fledged organs yet, but only organoids - rudiments, an unfinished collection of cells and tissues that can only be used as experimental samples. Their performance and livability are tested on experimental animals, mainly on different rodents.

Historical reference. Transplantology

The growth of bioengineering as a science was preceded by a long period of development of biology and other sciences, the purpose of which was to study human body. At the beginning of the 20th century, transplantology received an impetus for its development, the task of which was to study the possibility of transplanting a donor organ to another person. The creation of techniques capable of preserving donor organs for some time, as well as the availability of experience and detailed plans for transplantation, allowed surgeons from all over the world to successfully transplant organs such as the heart, lungs, and kidneys in the late 60s.

On this moment The principle of transplantation is most effective if the patient is in danger of deadly danger. The main problem is the acute shortage of donor organs. Patients can wait for their turn for years without getting it. In addition, there is a high risk that the transplanted donor organ may not take root in the recipient’s body, since immune system patient he will be considered as foreign object. Into confrontation this phenomenon Immunosuppressants were invented, which, however, are more likely to cripple than to cure - human immunity is catastrophically weakened.

Advantages of artificial creation over transplantation

One of the main competitive differences between the method of growing organs and transplanting them from a donor is that in laboratory conditions organs can be produced on the basis of tissues and cells of the future recipient. Basically, stem cells are used that have the ability to differentiate into cells of certain tissues. This process the scientist is able to control from the outside, which significantly reduces the risk of future organ rejection by the human immune system.

Moreover, using the method artificial cultivation organs can be produced in unlimited quantities, thereby satisfying the vital needs of millions of people. The principle of mass production will significantly reduce the price of organs, saving millions of lives and significantly increasing human survival and pushing back the date of its biological death.

Advances in bioengineering

Today, scientists are able to grow the rudiments of future organs - organoids, on which they test various diseases, viruses and infections in order to trace the infection process and develop counteraction tactics. The success of the functioning of organoids is tested by transplanting them into the bodies of animals: rabbits, mice.

It is also worth noting that bioengineering has achieved certain successes in creating full-fledged tissues and even in growing organs from stem cells, which, unfortunately, cannot yet be transplanted into humans due to their inoperability. However, at the moment, scientists have learned to create artificially cartilage, blood vessels and other connecting elements.

Skin and bones

Not long ago, scientists at Columbia University managed to create a bone fragment with a structure similar to a joint. lower jaw connecting it to the base of the skull. The fragment was obtained through the use of stem cells, as in growing organs. A little later, the Israeli company Bonus BioGroup managed to invent new method recreating a human bone, which was successfully tested on a rodent - the artificially grown bone was transplanted into one of its paws. In this case, stem cells were again used, only they were obtained from the patient’s adipose tissue and subsequently placed on a gel-like bone scaffold.

Since the 2000s, doctors have been using specialized hydrogels and natural regeneration methods to treat burns. damaged areas skin. Modern ones experimental techniques allow you to cure severe burns in a few days. The so-called Skin Gun sprays a special mixture of the patient's stem cells onto the damaged surface. There are also major advances in creating stable functioning skin with blood and lymphatic vessels.

Recently, scientists from Michigan managed to grow in laboratory conditions a piece of muscle tissue, which, however, is half as weak as the original one. Similarly, scientists in Ohio created three-dimensional stomach tissues that were able to produce all the enzymes needed for digestion.

Japanese scientists have accomplished the almost impossible - they have grown a fully functioning human eye. The problem with transplantation is that to attach optic nerve eyes to the brain is not yet possible. In Texas, lungs were also grown artificially in a bioreactor, but without blood vessels, which casts doubt on their functionality.

Development prospects

It won’t be long until the moment in history when it will be possible for a person to transplant most of the organs and tissues created in artificial conditions. Already, scientists from all over the world have developed projects and experimental samples, some of which are not inferior to the originals. Skin, teeth, bones, everything internal organs after some time it will be possible to create in laboratories and sell to people in need.

New technologies are also accelerating the development of bioengineering. 3D printing, which has become widespread in many areas human life, will also be useful in growing new organs. 3D bioprinters have already been used experimentally since 2006, and in the future they will be able to create three-dimensional workable models of biological organs by transferring cell cultures to a biocompatible substrate.

General conclusion

Bioengineering as a science, the purpose of which is to grow tissues and organs for their further transplantation, originated not so long ago. The leaping pace at which it is marching along the path of progress is characterized by significant achievements that will save millions of lives in the future.

Bone and internal organs grown from stem cells will eliminate the need for donor organs, the number of which is already in short supply. Scientists already have many developments, the results of which are not yet very productive, but have enormous potential.

Before starting to discuss the topic of the article, I want to make a short excursion into what the human body is. This will help you understand how important the work of any link in complex system human body what can happen in case of failure, and how modern medicine tries to solve problems if any organ fails.

The human body as a biological system

The human body is a complex biological system that has a special structure and is endowed with specific functions. Within this system there are several levels of organization. The highest integration is the organismic level. Further descending are the systemic, organ, tissue, cellular and molecular levels of organization. The coordinated work of the entire human body depends on the coordinated work of all levels of the system.
If some organ or organ system does not work correctly, then the violations affect more lower levels organizations such as tissues and cells.

The molecular level is the first building block. As the name suggests, the entire human body, like all living things, consists of countless molecules.

The cellular level can be imagined as diverse component composition molecules that make up different cells.

Cells united into tissues of different morphology and functioning form the tissue level.

Human organs contain a variety of tissues. They provide normal functioning any organ. This is the organ level of organization.

The next level of organization is systemic. Certain anatomically united organs perform a more complex function. For example, digestive system, consisting of various organs, ensures the digestion of food entering the body, the absorption of digestive products and the removal of unused residues.
AND highest level organizations – organismal level. All systems and subsystems of the body work like a well-tuned musical instrument. Coordinated work of all levels is achieved thanks to the mechanism of self-regulation, i.e. support at a certain level of various biological indicators. At the slightest imbalance in the functioning of any level, the human body begins to work intermittently.

What are stem cells?

The term “stem cells” was introduced into science by the Russian histologist A. Maksimov in 1908. Stem cells (SC) are unspecialized cells. They are still considered as immature cells. They are present in almost all multicellular organisms, including humans. Cells reproduce themselves by dividing. They are capable of turning into specialized cells, i.e. from them can be formed various fabrics and organs.

The most a large number of KS in infants and children; in youth, the number of stem cells in the body decreases by 10 times, and in adulthood - by 50 times! A significant decrease in the number of SCs during aging, as well as serious illnesses reduces the body's ability to heal itself. This leads to an unpleasant conclusion: the life activity of many important systems organs decreases.

Stem cells and the future of medicine

Medical scientists have long paid attention to the plasticity of SCs and the theoretical possibility of growing various tissues and organs of the human body from them. Work on studying the properties of SC began in the second half of the last century. As always, the first studies were carried out on laboratory animals. By the beginning of this century, attempts began to use SCs for growing human tissues and organs. I would like to tell you about the most interesting results in this direction.

In 2004, Japanese scientists managed to grow capillary blood vessels from SC in laboratory conditions.

IN next year American researchers from Florida State University managed to grow brain cells from SCs. Scientists said such cells can be implanted into the brain and could be used to treat diseases such as Parkinson's and Alzheimer's.

In 2006, Swiss scientists from the University of Zurich grew human heart valves in their laboratory. For this experiment, SCs from amniotic fluid were used. Dr. S. Hoerstrap believes the technique could be used to grow heart valves for an unborn child who has heart defects. After birth, the baby can receive new valves grown from amniotic fluid stem cells.

In the same year, American doctors grew an entire organ – the bladder – in the laboratory. SCs were taken from the person for whom this organ was grown. Dr. E. Atala, director of the Institute of Regenerative Medicine, said that cells and special substances are placed in special form, which remains in the incubator for several weeks. After this, the finished organ is transplanted into the patient. Such operations are now performed as usual.

In 2007, at an international medical symposium in Yokahama, Japanese specialists from the University of Tokyo presented a report on an amazing scientific experiment. From a single stem cell taken from the cornea and placed in a nutrient medium, it was possible to grow a new cornea. Scientists intended to begin clinical research and further use this technology in eye treatment.

The Japanese are the leaders in growing a tooth from a single cell. The SC was transplanted onto a collagen scaffold and the experiment began. After growing, the tooth looked like a natural one and had all its components, including dentin, blood vessels, enamel, etc. The tooth was transplanted into a laboratory mouse, took root and functioned normally. Japanese scientists see great prospects for using this method in growing a tooth from one SC and then transplanting the cell into its owner.

Japanese doctors from Kyoto University managed to obtain kidney and adrenal tissue and a fragment of a renal tubule from SCs.

Every year, millions of people around the world die from diseases of the heart, brain, kidneys, liver, muscular dystrophy etc. Stem cells can help treat them. However, there is one point that can slow down the use of stem cells in medical practice is the lack of international legislative framework: where the material can be taken from, how long it can be stored, how the patient and his doctor should interact when using SC.

Probably, the conduct of medical experiments and the development of such a law should go in parallel.