Stem cells can multiply or make more of themselves. They can also turn into specialized cells that make up your blood, brain, muscles, bones, and more.
Researchers study them to learn if these basic building blocks of life can help unlock new medical treatments. They can also shed light on why certain health conditions and diseases happen.
Because stem cells may be a way to replace diseased or damaged cells, the hope is that research could one day lead to breakthroughs in treatment for conditions like:
- Parkinson’s disease
- Alzheimer’s disease
- Spinal cord injuries
- Heart disease
Researchers are also looking into the role certain stem cells might play in helping drugmakers test the safety and effectiveness of medications. The idea is that they’d be changed in the lab to become like the specialized cells a given drug targets. Researchers could then test the drug on those specialized cells to see if it works.
Where Do Stem Cells Come From?
There are two main types of stem cells: embryonic and adult.
Embryonic stem cell research uses cells that come from embryos. These are fertilized eggs that weren’t used during in vitro fertilization (IVF). In other words, the doctor didn’t put them in a person’s womb. It’s common for people who get IVF to have leftover embryos, and they have the option to donate them to science for research. Embryonic stem cells have the potential to make every type of cell in the body.
Despite the name, adult stem cells are found in babies, children, and adults. They usually make cells for the organ or tissue where they’re located. For example, an adult stem cell in the skin would make more skin cells.
Scientists can change adult stem cells in the lab to make them act more like embryonic stem cells. These are called induced pluripotent stem cells (iPS). They’re a hot topic among researchers because they’re a good way to make lab-made stem cells for a specific disease. These disease-specific stem cells help researchers study the cause of a certain illness and then test drugs or discover other ways to treat or cure that illness.
Researchers have also found stem cells in amniotic fluid and umbilical cord blood. These cells can also turn into specialized stem cells.
Which Treatments Use Stem Cell Research?
The only stem cell-based treatments that the FDA has approved are made of blood-forming cells that come from umbilical cord blood. They’re approved for use in people with disorders that affect your body’s ability to make blood. Doctors also use stem cells from bone marrow for these treatments -- the FDA just generally doesn’t regulate them for that use.
A stem cell transplant can be a treatment for conditions such as:
- Cancers like leukemia and lymphoma
- Blood disorders like sickle cell anemia
- Autoimmune diseases like multiple sclerosis
Stem cell transplants can also help replace bone marrow cells destroyed by cancer or cancer treatments, such as chemotherapy and radiation.
What’s more, doctors can treat some diseases or injuries that affect bones, skin, and the cornea (the outer layer of your eye) by grafting tissues that come from or are maintained by stem cells.
Is Stem Cell Research Legal in the U.S.?
Yes, but each state’s laws are different. Some states encourage embryonic stem cell research, but many have different restrictions in place. States that specifically allow embryonic stem cell research have set up guidelines for scientists, like consent rules, and approval and review procedures for projects.
What Are Some Challenges Researchers Face?
Adult stem cell research has been going on for decades, but scientists have much more to learn about embryonic stem cells. They’ve only been studying them since 1998. If researchers get a clearer idea of how embryonic stem cells form, it could help them understand how to control the kinds of cells made from them. But some people aren’t comfortable with the idea of using stem cells that come from embryos.
Another challenge is that many researchers find it hard to grow adult pluripotent stem cells in the lab. These cells are also present in small amounts throughout the body, but there is a higher chance that they could have DNA problems.