This century is witnessing huge advances in medical technology, including the rapidly developing — and enthusiastically embraced — field of stem cell and regenerative medicine. Stem cells are the body’s master cells, with the ability to divide throughout their life cycle to create highly specialized new cells, such as muscle, red blood or brain cells.

Stem cells are crucial for the development of living organisms, and researchers are working with two types — those from animals (embryonic cells) and those from humans (adult cells). During the early stages of embryo development, stem cells give rise to the organism’s entire body, including the heart, lungs, skin, sperm and eggs. In some adult tissues, such as bone marrow, muscle and brain, discrete populations of adult stem cells generate replacements for cells that are lost through normal wear and tear, injury, or disease.

REGENERATIVE MEDICINE This is an exciting new field that holds out hope for any number of diseases. In regenerative medicine, scientists use human stem cells to test new drugs to understand normal growth and identify the causes of birth defects. A method of growing cells in the laboratory, known as cell culturing, can be used to grow embryonic stem cells — a significant scientific advancement to avoid the risk of viruses.

Due to their unique regenerative abilities, stem cells offer a renewable source of replacement cells and tissues to treat muscular degeneration, spinal cord injuries, stroke, burns, heart disease, diabetes, osteoarthritis, rheumatoid arthritis, traumatic spinal cord injuries, heart disease, and vision and hearing loss.

The recent discovery of induced pluripotent stem (iPS) cells signaled a new era in human biology. These cells offer hope for a renewable source of replacement cells and tissues to treat a myriad of diseases.

Stem cells offer exciting promise for future therapies, but significant technical hurdles remain unresolved. Tissue regeneration is probably the most important possible application of stem cells. Currently, organs must be donated and transplanted, but demand for organs far exceeds the supply. Stem cells could potentially be used to grow a particular type of tissue if directed to differentiate in a certain way. For instance, stem cells that lie just beneath the skin can be used to culture new skin tissue that can be grafted onto burn victims.

The use of embryonic and adult-derived stem cells for cardiac repair is a new research area. Stem cells are being investigated for their ability to regenerate and repair damaged heart tissue, which could provide an effective treatment for cardiovascular disease.

In Type 1 diabetes, the pancreatic cells that produce insulin are destroyed by the immune system. New studies indicate that it is possible to direct the differentiation of human embryonic stem cells in a cell culture to create insulin-producing cells for transplant.

Treatment of Parkinson’s and Alzheimer’s diseases is now possible by replenishing the damaged brain tissue. Embryonic stem cells can be directed to differentiate into these types of cells, indicating the possibilities of promising treatments.

INTERNATIONAL SCENARIO The International Society for Stem Cell Research, an independent nonprofit organization, has been established in many countries to promote exchange and dissemination of knowledge relating to stem cells. It encourages research on stem cells to promote professional and public education.