A Complete “Makeover”
The human body is in a continual state of regeneration as worn out cells die off and new, healthy cells replicate. In fact, our bodies go through a complete “makeover” every 5-10 years; for instance, the cells of our skeletal system are replaced every 10 years, liver cells every 2 years, while red blood cells are renewed every three to four months.
And if we’re in good health, our body’s response to injury is just as astonishing. Cuts can be sutured, broken bones reconnected, and healthy organs can be transplanted to replace injured ones.
But many of the traditional procedures that physicians use, such as surgeries and transplants, are limited in nature and only restore partial or temporary function to tissue, organs, and joints.
What if a cancerous tumor could be replaced by healthy cells that would restore a kidney or a lung back to its healthy state? Or if cells could be injected into an arthritic joint to ease pain and regrow cartilage that had worn away? In recent years, physicians have shifted their focus to regenerative medicine; methods and technologies that encourage healthy new cells to proliferate and grow.
Born to be Alive
The problem is, once our cells start to deteriorate with age, or when injury or disease occurs, our bodies weaken and we slowly lose strength and mobility. Our cells are eventually unable to replicate into healthy new cells.
At the focal point of regenerative medicine are stem cells. We’re used to hearing about these types of cells because of the ethical controversy of harvesting them from embryos. They’re present at this phase of human development for obvious reasons; stem cells can either replicate into more stem cells or differentiate into any other type of body cell.
Researchers are studying the activity of stem cells when they’re injected into a site where a patient’s own cells have been lost due to injury or disease. They’re hoping that stem cells could be used to encourage growth that would replace missing or worn out cells, replenish tissue, and speed up the healing process.
They’ve successfully used stem cells to treat some types of bone and blood cancers and they’re experimenting with their potential use in treating arthritis, diabetes, heart disease, and most significantly, brain and spinal cord injuries.
If stem cell therapies could potentially cure diseases and slow the aging process, then the challenge becomes, where to find them?
Stem cells normally grow in small numbers in our bone marrow, liver, and brain. However, these only have the ability to grow into the same type of cell where they’re located.
Most of the stem cells being used in research have been harvested from sources related to pregnancy. They’re present in the placenta, in umbilical cord blood, and in the amniotic fluid that surrounds a fetus during gestation.
Embryonic stem cells are the most valuable to medical research because they’re “pluripotent,” meaning they have the ability to differentiate into any other type of body cell. Harvesting these is somewhat controversial, though, because they’re extracted in a laboratory from discarded embryos.
In 2007, Shinya Yamanaka and Sir John Gurdon discovered a method for changing a normal adult body cell back into a stem cell by manipulating it’s DNA. These induced pluripotent stem cells respond the same way as embryonic stem cells, replicating themselves and differentiating into other types of body cells.
IPSC’s might even have benefits that embryonic stem cells don’t. Generating them isn’t at all controversial and, ideally, a patient could have a supply of them stored up for future use to treat a variety of conditions. IPSC’s are currently being used in the laboratory to test for the side effects of certain “patient-matched” medications. And the fact that a patient’s own cells are sourced to create the iPSC means that there is little risk of rejection when used in tissue transplants.