What are stem cells? How are they regulated?
Stem cells are cells that have the ability to divide and develop into many different cell types in the body during early life and growth. Stem cells may also help repair the body by dividing to replenish cells that are damaged by disease, injury, or normal wear. When a stem cell divides, each new cell has the potential either to remain a stem cell or to become another type of cell with a more specialized function, such as a nerve cell, a skin cell, or a red blood cell.
Three types of stem cells have been identified:
1. adult stem cells
2. human embryonic stem cells
3. induced pluripotent stem cells
These three types of stem cells share properties:
- They are capable of surviving over long periods and divide to make additional stem cells.
- They are unspecialized (“blank slates” that can become specific types of cells).
- They can develop into specialized cell types (cells that do specific work in the body).
Adult stem cells can be found throughout the body. They are found as unspecialized cells among the specialized cells in tissues and organs as well as in umbilical cord blood and peripheral blood (that is, hematopoietic stem cells). An adult stem cell can either divide to make more adult stem cells, or differentiate to produce some or all of the major specialized cell types of the tissue or organ.
Human embryonic stem cells (hESC) come from embryos that develop from eggs that have been fertilized in vitro (in a test tube or another artificial environment). Embryonic stem cells can develop into any specialized cell type in the body.
Induced pluripotent stem cells (iPS) are generated by reprogramming adult cells that have already differentiated into a specific cell, such as a skin cell. After reprogramming, iPS cells are able to develop into any specialized cell type in the body.
Stem cells, like other medical products that are intended to treat, cure or prevent disease, generally require FDA approval before they can be marketed. At this time, there are no licensed stem cell treatments.
- Webinar on FDA’s Safety Monitoring of Approved Vaccines
- FDA Basic Video: Dianne Murphy Discusses Effective and Proper Uses of Medicines and Devices in Children (Video)
- FDA Basic Video: Norman Baylor Discusses Vaccines (Video)
- FDA Webinar on Safety of the Blood Supply
- FDA Webinar on Protecting Your Child's Health Through Safe and Effective Vaccines
- What are stem cells? How are they regulated?
- What is thimerosal? Is it safe when used in some vaccines?
- How can I get my name removed from a donor deferral list?
- What is a biological product?
- How does FDA regulate tissue products? What safeguards are in place for recipients?
- How do I know if I’m eligible to donate blood?
- How do I report an adverse event related to a vaccine?
- What is the Vaccine Adverse Event Reporting System (VAERS)?
- How does FDA assess the safety of vaccines?
- What is the approval process for a biological product?
How helpful was this information?