Every tissue and organ of human body is composed of different types of cells. The nerve cells are different from the cardiomyocytes or cells of the heart. It is impossible to transfer a differentiated cell from a tissue or an organ to another. However, all cells have one thing in common: they come from one cell source. During early stages of cell development, these cells can become any tissue or organ, that is to say they are not yet specialized and they retain the property of totipotency. These cells are called stem cells.
Stem cells have two important characteristics that differentiate them from other cell types. Firstly, as mentioned above, all stem cells are unspecialized, which means they can differentiate into any type of cell irrespective of their tissue type. Stem cells can renew themselves for long periods through cell division. When they receive chemical signals, they can differentiate. This means they can divide to generate cells that have special functions, such as respiratory muscle cells of heart or pancreatic cells that produce insulin.
The research of the stem cells aims at gaining control over cell differentiation. This will enable researchers to generate potentially any organ or tissue from a single stem cell. This involves the study of the genetic nature of the stem cells, their physiology , the biological factors they contain and their receptors that receive the signals about cell differentiation. Scientists have been working on generating adult stem cells that can be transformed into various functional tissue types like the neurocytes or the cardiomyocytes. One such stem cell that has been studied extensively is hematopoietic stem cells. These are the cells involved in generation of white and red blood cells.
Stem cells can be employed to create enzymes or factors like insulin and introduced in the body. This would result in the natural production of insulin in the body of an insulin deficient patient and the need for an external source of insulin would stop. Stem cells can also be transformed into cells to resist infections from known strains of viruses. There are several researches being carried out to study the possibility of stem cells that could resist HIV. Their basic objective will be to reinvigorate the immune system of the AIDS patients by producing and differentiating into cells resistant to the virus. With a cell mass resistant to the HIV and the immune strength restored back to normal, the body of the patient can put up great resistance against AIDS.
Stem cell research can immensely contribute towards tissue engineering as they could be used to produce part or full organs like liver, kidneys, eyes and even heart or parts of brain. This can make a great difference to the patients suffering from neurological disorders and other ailments. In future, this will solve the problem of mismatches and transplants for dysfunctional organs in the body of the recipient.
Stem cells can have applications in various areas of medicine and biotechnology. They can facilitate the study of natural and induced genetic mutations on the body and tissues. As the source is stem cell from the human body, the results of the research and experiments will be more accurate and informative than similar experiments carried with animal models.