Amid all the hype and ethical debate about stem cell therapy, one mode of delivering stem cell treatments for tissue engineering and regenerative medicine remains medically sound: adipose-derived stem cell (ASC) treatment using adipose (fat) tissue taken from the patient’s own body.
While these cells are available from umbilical cord blood and animals, the problem presented by introducing tissue from another person or an animal remains the same: the risk of tissue rejection poses its own set of health risks and makes regenerative therapy expensive.
Stem cells are valued in medicine because of their ability to self-renew. These cells have yet to be assigned specific functions and can be used to grow tissue for nerves, cartilage to ease degenerative arthritis, and tissue to repair a damaged heart.
An extensive study undertaken by researchers Jeffrey Gimble, Adam Katz and Bruce Bunnell published in the March 2007 edition of the American Heart Association’s Circulation Research Journal found that fat can be harvested from the patient’s own body in sufficient amounts for regenerative therapy at negligible risk of tissue rejection.
Adipose tissue can be harvested through liposuction, a minimally-invasive procedure. Because ASC can be done on an outpatient set-up, the risk of tissue contamination is also greatly reduced and the physician’s control over the process is improved.
The availability of stem cells remains a challenge for scientists and clinicians in the field of regenerative medicine. Owing to the abundant supply of adipose tissue in the patient’s own system, this limitation is readily surmounted.
The researchers focused on the adipose tissue deposits found beneath the skin, the same tissue siphoned out when a person undergoes liposuction. One liposuction session can yield “between 100 mL to more than three liters” of aspirated fatty tissue.
The study found that the greatest amount of viable adipose tissue recovered from the arm as compared with the thigh, abdomen, and breast. ASCs, the researchers found, are “tripotent”, capable of producing more fat, bone marrow, and bone tissue.
“Adipose tissue contains multipotent progenitor cells,” the researchers stated. These cells develop into specific tissues as the body demands.
The team pointed to a number of nonexclusive mechanisms through which ASCs can be used to repair and regenerate tissues. “First, ASCs delivered into an injured or diseased tissue may secrete cytokines and growth factors that stimulate recovery.”
The study said that ASCs might also provide antioxidants chemicals, free radical scavengers, and heat shock proteins that locate and recycle damaged proteins.