Stem cells
Stem cells are one of the most promising discoveries in biomedicine in recent years.
From any cell of the embryo in the early stages of development, like branches from a trunk, any of the hundreds of cell types that make up our body can grow. In an adult organism, specialized cells are unable to divide or differentiate into other cell types. In diseases, injuries, poisoning and age–related changes, cells die, and their recovery occurs only at the expense of stem cells: specialized regional and universal - mesenchymal, which, as a strategic reserve, are stored in the bone marrow. They, like the cells of the embryo, can divide and turn into cells of various tissues. But their resources are limited, and with age, the stocks of stem cells are depleted, their activity decreases, and by the time the body needs repairs more and more often, there are not enough spare parts in it even to simply keep it on the go, and even more so for major repairs.
If you extract from the bone marrow, multiply and inject a dozen or two million stem cells directly into the injury site or just into a vein, you can cure many diseases. In addition to their own mesenchymal cells, donor stem cells (including from umbilical cord blood) and fetal cells are used in medicine – obtained from the so-called abortive material.
Reports of another successful application of cell therapy for the treatment of new diseases appear daily. The list of diseases that are already being treated with cell therapy has long exceeded a hundred. These include those in which traditional medicine can offer, for example, amputation (with age-related or diabetic disorders of the blood supply to the legs) or heart transplantation (with severe heart failure). In oncology, the use of stem cells that restore healthy cells destroyed by chemo or radiotherapy increases the chances of recovery many times, and in oncological diseases of the hematopoietic system is already an obligatory part of the treatment protocol.
In addition, researchers are already using tissue engineering methods to create bone sections from stem cells (including almost all of them, except for the jaw joints, the lower jaw), transplant blood vessels, heart valves, bladders, ligaments and tendons grown from their own cells to patients (including with such a common injury as rupture of the meniscus of the knee joint), phalanges of the fingers (also a very common injury), restore the vocal cords, eardrums, bile ducts, trachea and intestines… And the restoration of the skin, cornea, bone and cartilage with a transplant from the patient's own cells in some clinics around the world is already becoming a routine procedure.
In animal experiments, kidneys and even eyes were grown and successfully functioned. Many groups of researchers are working on improving the method of layered three-dimensional printing of blanks of future organs. With the help of a specialized inkjet printer, it is possible to create a frame from a biodegradable polymer in which the structure of the organ is formed by stem cells already differentiated in the right direction – to turn into blood vessels, muscles, connective tissue, etc. Along with the cells, various growth factors are introduced into the workpiece – biologically active molecules that stimulate cell division and their final specialization. Such an organ can be grown in a bioreactor or even in the body of the patient himself – in the abdominal cavity or in the muscles, and transplanted to the place of the worn one. According to the wildest forecasts, the first human artificial hearts, kidneys, lungs, etc. will be created in the next 10 years.
In addition to the development of cellular technologies proper, the study of stem cells is also necessary for a better understanding of the processes of aging and carcinogenesis: the mechanisms that ensure both neoplastic processes and the properties of stem cells have much in common.
In a few years, methods of growing teeth, hair and mammary glands from stem cells will be introduced into widespread practice. At different stages of clinical trials necessary for permission to use them in any licensed medical institution, there are methods of treatment with stem cells of heart attack, stroke, severe injuries, including spinal cord, diabetes and dozens of other diseases, including typically senile – arthrosis, Parkinsonism, Alzheimer's disease, etc. And in relatively healthy people the introduction of stem cells is used in cosmetology and for revitalization – rejuvenation of the body.