It has been called the age of stem cells, the seemingly magic root cells of life that can be used to generate almost every other type of cell, possibly opening a door to a new world of regenerative therapy. Hardly a day goes by that some new stem cell development isn't announced, and yet actual treatments involving stem cell technology are still very limited. Much has yet to be learned.
The idea behind stem cells has in fact been around for a very long time. Ever since the invention of the microscope and the development of cell theory, scientists have known that somehow the complex collection of specialized cells that make up the human body have their origin in a single fertilized egg. It was clear that, somewhere during the earliest stages of the developmental process, cells were being systematically transformed into specialized heart cells or nerve cells or liver cells or blood cells. The term "stem cell" was used as early as the late 1800s, before anything was really known about particular stem cells, but, by the early 1900s, it was recognized that different blood cells were all parented by a particular stem cell. By the early 1960s, there was a better understanding of the operation of bone marrow cells and the production of blood cells, which eventually led to today's bone marrow transplants, the transplanting of adult stem cells for the treatment of leukemia and other blood related diseases.
As the technology to grow and work with human cells increased in the late 20th century, human stem cell research took off. Soon the first human embryonic stem cell lines were introduced, which scientists were able to use to fully establish the remarkable abilities of stem cells, suggesting their possible use in generating replacement cells for a broad range of tissues and organs. Since then, researchers have gained a deeper knowledge of the different types of stem cells, how to manipulate them, and the applications for which they can be most effectively used.
Nevertheless, for all of its promise, most forms of stem cell research and application present a number of challenges. The most public issue involves the ethics of using stem cells derived from human embryos, but there are other questions. Might stem cells, because of the way some are cultivated, pass on viruses that could actually cause disease? Could the improperly controlled growth of embryonic stem cells lead to tumors? There are also ongoing questions about how to economically generate enough stem cells for practical therapeutic use without damaging the biological effectiveness of the cells in the process.
There are several different categories of stem cells, from different sources, and with different capabilities, and this determines how practical they might be for therapeutic application.
· Totipotent - These are the most basic of stem cells, resulting from the initial fusion of egg cell and sperm cell and its immediate offspring. It can differentiate into any type of cell and can even build a complete organism.
· Pluripotent - These are the descendants of totipotent cells. They can differentiate into almost any type of cell, though they cannot build a complete organism.
· Multipotent - These are able to differentiate into a number of cells, but only those of the same basic type, such as a blood cell or a brain cell.
· Oligopotent - These are able to differentiate into only a few specific cells.
· Unipotent - These are able to produce only one type of differentiated cell, but are still considered stem cells because of their ability to self-renew, meaning that they can spin off a differentiated cell while remaining unchanged themselves.
To obtain the right kind of stem cell, with the ability to do what is needed, requires getting it from the right source and/or changing the cell's nature through outside manipulation. Stem cells obtained from human embryos are pluripotent, with characteristics especially valuable to researchers. Developed human beings also carry stem cells, adult stem cells, but they are tougher to find and have a limited ability to differentiate.
In addition, scientists now have the ability to manipulate cells, changing some aspect of their basic nature, such as inducing pluripotency. This is important, since pluripotent human stem cells derived from human embryos remain the center of a firestorm of controversy. However, induced pluripotent stem cells, differentiated cells that are chemically or otherwise forced back to an earlier developmental stage, may face a barrage of regulatory scrutiny before they are ever allowed for therapeutic application.
There are an increasing number of publicly traded companies focused exclusively on stem cell research, primarily for potential therapeutics.
· International Stem Cell Corporation (OTC:ISCO) could be the most promising as the company has developed a breakthrough technology that provides pluripotent stem cells without using viable human embryos and without the issues associated with induced pluripotent stem cells or adult stem cells. It's called parthenogenesis, based upon unfertilized human eggs, and also allows superior immune-matching capabilities. Learn more here.
A caveat here for investors ... this is a stock which trades below $1 per share. It is therefore less liquid and more volatile than other non-penny stocks. Please exercise your due diligence before placing any orders on such stocks.
Geron (GERN) is a world leader in the development of human embryonic stem cell-based therapeutics, with its spinal cord injury treatment anticipated to be the first product to enter clinical development. The company is also developing biopharmaceuticals for the treatment of cancer and chronic degenerative diseases. Learn more at here.
· Osiris Therapeutics, Inc. (OSIR) is a leading stem cell therapeutic company researching the treatment of inflammatory, orthopedic, and cardiovascular diseases. Their products are designed to regulate inflammation and promote tissue regeneration. Learn more here.
· Neuralstem, Inc. (CUR) is a biotherapeutics company applying its patented human neural stem cell technology to treat diseases of the central nervous system, such as Traumatic Spinal Cord Injury, ALS, and Parkinson's Disease. Learn more here.
People with diseases that currently have no effective treatment options available to them will finally have hope of survival and better quality of life as stem cell research continues to advance. It's truly an exciting time for medical science and the possibilities are endless.