Stem Cells Explained

Adult Stem Cells (Somatic Stem Cells)

• Replace old cells and repair damaged tissues.
• Examples of cells that need replacing:
  • Taste buds (every 10 days)
  • Skin cells (every couple of weeks)
  • Liver cells (every 300-500 days)
• Undifferentiated: Haven't specialized yet.

Types of Adult Stem Cells

• Pluripotent:
  • Can become many different types of cells all over the body.
  • Difficult to find due to low quantity in each organ/tissue.
• Multipotent:
  • More common in the body.
  • Restricted in the types of cells they can become.

Embryonic Stem Cells

• Pluripotent: Can become any type of cell in the body.
• Sourced from human embryos (blastocyst stage – 4-5 days old).
  • Embryo is destroyed when stem cells are extracted.
  • Obtained from in vitro fertilization (IVF) clinics with donor consent.

Advantages of Embryonic Stem Cells

• Can be grown in culture (nutrient solution) for longer and faster than adult stem cells.
  • Example: 30 embryonic stem cells can yield millions in 6 months.
• Less likely to be rejected in transplant therapies compared to adult stem cells.

Stem Cell Research

• Used to repair/replace damaged cells and organs.
• Used to create new drugs.
• Regulations: U.S. has fewer stem cell lines available for federally funded research compared to Europe.
  • US: ~35 stem cell lines.
  • Europe: ~2,000 stem cell lines.