Stem Cells

Currently, a major focus of biomedical researchers has been the study of stem cells. Stem cells can be categorized in three major groups. The first major group is known as embryonic stem cells (ES). These stems cells are derived, as their name suggests, from embryos that were formed in vitro. These cells can be further classified into totipotent and pluripotent. The totipotent stem cells are obtained from a fertilized egg in its earliest stages, whereas pluripotent stem cells are obtained from the blastocyst. These embryonic stem cells have not yet differentiated, thus, they can be used in any part of the body and become specific to a given tissue, organ, etc. This research as been hindered by the moral dilemma regarding whether or not a fertilized embryo is considered alive.

Totipotent and pluripotent stem cells

Another major category of stem cells is induced pluripotent stem cells (iPS). These cells are adult stem cells which are essentially "reprogrammed" to exhibit behaviors of an embryonic stem cell. They behave has pluripotent stem cells and can develop all of the germ layers of a normal cell, and then differentiate.

The final major category of stem cells is adult stem cells, also known as somatic stem cells. These cells are undifferentiated and are retrieved from mature tissues, as opposed to embryonic stem cells. While they can differentiate to be any type of cell, they typically differentiate to be the same type of cell as its surrounding tissue.

Cell differentiation

These cells can be manipulated to specialize in a laboratory. After retrieving a sample of the desired stem cells, the scientists then remove the outermost layer of the blastocyst, and allow them to foster in a petri dish. Colonies of the cells begin to grow, and as they do, certain cells begin to develop into endoderm, mesoderm and ectoderm cells. Scientists can then manipulate the differentiation by adding growth factors, causing the cell to believe that its environment is that of a specific tissue type. This process results in the differentiation of a cell.



Cell development



Stem cells are invaluable to curing and treating various diseases. Currently, stem cells are being utilized to treat blood-cell disorders and in bone marrow. Ongoing research is studying the possibilities of using stem cells to treat damaged cardiac muscle in heart disease, creating skin grafts for burn victims, repairing the spinal cord, treating Parkinson's disease, Alzheimer's disease, diabetes, osteoarthritis, and rheumatoid arthritis.

Potential usage of stem cells to treat heart disease