What are Stem Cells?
Stem cells have the remarkable potential to develop into many different cell types in the body during early life and growth. In addition, in many tissues they serve as a sort of internal repair system, dividing essentially without limit to replenish other cells as long as the person or animal is still alive. When a stem cell divides, each new daughter cell has the potential either to remain a stem cell or become another type of cell with a more specialized function, such as a muscle cell, a red blood cell, or a brain cell.
Stem cells are distinguished from other cell types by two important characteristics. First, they are unspecialized cells capable of renewing themselves through cell division, sometimes after long periods of inactivity. Second, under certain physiological or experimental conditions, they can be induced to differentiate into tissue- or organ-specific cells with specialized functions. In some organs, such as the gut and bone marrow, stem cells regularly divide to repair and replace worn out or damaged tissues. In other organs, however, such as the pancreas and the heart, stem cells only divide under special conditions.
What are Adult Stem Cells?
There are two primary types of stem cells, embryonic and adult stem cells. As the name suggests, the controversial embryonic stem cells are derived from embryos. A previously overlooked alternative source for therapeutic stem cells resides within our own bodies, known as adult stem cells.
The adult stem cell is an undifferentiated cell that is found in a differentiated tissue. It has the ability to renew itself and become specialized to yield all the cell types of the tissue from which it originated and, in the appropriate environment, can also become a specialized cell of a different tissue. Adult stem cells are capable of self-renewal for the lifetime of the organism.
Adult stem cells have been found in numerous tissues including bone marrow, the blood stream, cornea and retina of the eye, the dental pulp of the tooth, liver, skin, gastrointestinal tract, adipose tissue and pancreas.
What are the Advantages of Adult Stem Cells?
The advantages of adult stem cells for cell therapeutics are many. Adult stem cells offer the possibility of a renewable source of replacement cells and tissues to treat a myriad of diseases, conditions and disabilities. Adult stem cells are relatively quiescent (inactive) cells, particularly in organisms where cell turnover is low, yet they can mount a rapid and strong response to tissue stress and injury.
As cells designed to withstand crisis and orchestrate repair, stem cells must be especially resilient. Until recently, it had been thought that a stem cell collected from the bone marrow or peripheral blood could not give rise to cells of a different tissue type, such as nerve cells. A number of clinical studies over recent years have confirmed the phenomenon known as plasticity. Plasticity is the ability of adult stem cells to differentiate into other cell types from a specific cell line. In other words, adult stem cells do have the ability in some circumstances, to differentiate into other cell types such as heart cells or nerve cells. NeoStem is investigating this capability of very small embryonic-like stem cells (NeoStem’s VSEL™ Technology).
This plasticity is another advantage of adult stem cells. Because of this plasticity, for certain indications, your own adult stem cells may be the perfect ethical and moral alternative to stem cells derived from other donors or from embryonic stem cells. Furthermore, when a patient’s own adult stem cells (autologous cells) are used to treat the patient, there are clinical and economic advantages, as there are no issues with immune rejection.
What are the Benefits of Stem Cell Research?
Adult stem cell transplants (bone marrow transplants) have been used for over 40 years in successfully treating cancers such as leukemia, multiple myeloma and lymphomas, and research has now opened the doors to regenerative and reparative therapeutics. There has been an increase in adult stem cell therapy clinical trials which are showing great promise in the areas of skin and wound healing, orthopedics, and in treating diseases including peripheral vascular disease, scleroderma, diabetes, congestive heart failure, myocardial infarction, and much more.
NeoStem’s research and development of VSEL™ Technology further illustrates the possible benefits of stem cell research. While it was previously believed that only controversial embryonic stem cells or costly induced pluripotent stem cells offered the potential for tri-lineage differentiation (that is, yielding cells of the endoderm, ectoderm, and mesoderm germ layers of a human), NeoStem has demonstrated that VSELs, found in many tissues of the human body, can do the same. This potential is why NeoStem is engaged in multiple grant-funded studies to investigate VSEL™ Technology and intends to file an investigational new drug application (IND) for the first human clinical trial of VSEL™ Technology.