Embryonic stem cell

Embryonic Stem Cell

Human embryonic stem cells

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

Diagram of stem cell types

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

Mouse embryonic stem cell-derived embryoid bodies

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 engineering.

Derivation

The derivation of embryonic stem cells involves isolating the inner cell mass from a blastocyst and culturing these cells in vitro. This process requires precise conditions to maintain the cells' pluripotency and prevent spontaneous differentiation.

Applications

Embryonic stem cells hold significant promise for therapeutic cloning and regenerative medicine. They can potentially be used to generate tissues and organs for transplantation, model diseases, and screen for new pharmaceuticals.

Ethical Considerations

The use of embryonic stem cells raises ethical concerns, primarily because the process of deriving these cells involves the destruction of a human embryo. This has led to debates about the moral status of the embryo and the ethical implications of using ESCs in research and therapy.

Research and Discoveries

Sir Martin Evans, Nobel Prize winner for his work on embryonic stem cells

The pioneering work of scientists such as Martin Evans, who was awarded the Nobel Prize for his contributions to the field, has paved the way for advancements in understanding and utilizing embryonic stem cells.

Induced Pluripotent Stem Cells

Induced pluripotent stem cells

Research into induced pluripotent stem cells (iPSCs) has provided an alternative to embryonic stem cells. iPSCs are generated by reprogramming adult cells to a pluripotent state, thus avoiding the ethical issues associated with ESCs.

Embryoid Bodies

When cultured in suspension, embryonic stem cells can form embryoid bodies, which are three-dimensional aggregates that can differentiate into various cell types, mimicking early embryonic development.

Related Pages

• Stem cell
• Pluripotency
• Regenerative medicine
• Therapeutic cloning
• Induced pluripotent stem cell