Embryonic stem cell

Embryonic Stem Cells

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Diagram of stem cell differentiation.

Embryonic stem cells (ESCs) are pluripotent stem cells derived from the inner cell mass of a blastocyst, an early-stage pre-implantation embryo. Human embryos reach the blastocyst stage 4–5 days post fertilization, at which point they consist of 50–150 cells.

Characteristics

Embryonic stem cells are characterized by their ability to differentiate into any cell type of the three germ layers: ectoderm, mesoderm, and endoderm. This pluripotency distinguishes them from adult stem cells, which are multipotent and can only differentiate into a limited range of cell types.

ESCs are also capable of self-renewal, meaning they can divide and replicate indefinitely while maintaining their undifferentiated state. This property is crucial for their potential use in regenerative medicine and tissue replacement after injury or disease.

Sources

Embryonic stem cells are typically derived from the inner cell mass of the blastocyst. The process involves isolating the inner cell mass and culturing it in vitro. This procedure raises ethical concerns, as it involves the destruction of the embryo.

Applications

Embryonic stem cells hold significant promise for regenerative medicine. They can potentially be used to generate cells and tissues for transplantation, including neurons for neurodegenerative diseases, cardiomyocytes for heart disease, and insulin-producing cells for diabetes.

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Stem cell research in a laboratory setting.

In addition to their therapeutic potential, ESCs are valuable for research purposes. They provide a model for studying early human development, understanding disease mechanisms, and testing new drugs.

Ethical Considerations

The use of embryonic stem cells is controversial due to ethical concerns regarding the destruction of human embryos. This has led to the development of alternative methods, such as induced pluripotent stem cells (iPSCs), which are derived from adult cells reprogrammed to an embryonic-like state.

Challenges

Despite their potential, several challenges must be addressed before ESCs can be widely used in clinical applications. These include the risk of immune rejection, the potential for tumor formation, and the need for precise control over differentiation.

Related Pages

• Stem cell
• Induced pluripotent stem cell
• Regenerative medicine
• Blastocyst
• Cell differentiation