A stem cell is a type of cell found in multi-cellular organisms that has the unique ability to propagate, differentiate and grow into many different types of cells. Stem cells are considered by many experts to be vitally important to medical advancements, as they can be stimulated to grow into organs, repair damaged tissue, or be transplanted into the body to help fight disease. A stem cell culture refers to cells that are removed from source material and grown under laboratory conditions. The use of stem cells is still in infancy as of the early 21st century, and human stem cell culture research remains an area of considerable ethical debate.
To create a stem cell culture, scientists remove cells from their original source and place them in a culture dish with liquid material that provides nutrients. The stem cells feed on the nutrients, sometimes with the aid of an additional layer of cells from another source, known as feeder sells. If the culture succeeds, the stem cells will begin to replicate by division. The new cells are placed in more culture environments to further the replication.
A stem cell culture is often grown for several months to establish a stable stem cell line. Until the line is established, the stem cells remain in a basic state that prevents them from turning into a specific type of cell, such as a blood cell. Once the stem cell culture has grown to a large enough size, chemicals or genetic material may be added to cause the cells to differentiate and morph into a specific cell form. Differentiation can also occur spontaneously, if cells gather together in certain combinations. For the purpose of some research, keeping cells from differentiating too early or without direction is a major concern.
Stem cell cultures can be used to create specific types of cells for medical treatment. Bone marrow cells can be grown and given to leukemia patients, to replace diseased cells killed by chemotherapy with healthy cells. Some early research has shown that stem cell therapy may be able to reverse or repair spinal cord damage, returning some ability to move or walk to paralyzed patients. Other studies show that stem cell treatments may even be able to stimulate regrowth in the body, potentially leading to the ability for humans to regrow hair, teeth, and even organs by stem cell injection. Many potential uses of stem cells are undergoing research in the early 21st century, while experts continue to express confidence that new treatments will be discovered with continued study.
Although stem cell experimentation has existed since the late 18th century, the use of human stem cells, particularly those from lab-fertilized human embryos, has raised serious ethical questions about the practice and potential outcomes of human stem cell research. Although according to experts, stem cell research may provide the key to a greatly advanced medical system, many believe that careful regulation is required to prevent improper treatment of human genetic material. As the debate rages on, many countries and medical research foundations have worked quickly to create laws and regulations that prevent unethical treatment and provide oversight to the process of maintaining, culturing, and experimentation on human stem cells.