Saturday, February 23, 2008
Can a Seaweed Wrap Help Beat Diabetes?
Seaweed could hold the secret to curing diabetes. An ingredient extracted from it is being wrapped around insulin-producing cells taken from pigs and injected into patients' bodies.
The jelly-like substance, called alginate, effectively hides the pig cells from the immune system, so it does not destroy them once they are injected.
This allows the animal cells to carry on producing insulin, potentially banishing the need for patients to inject themselves with the hormone up to four times a day.
It's a wrap: Alginate from seaweed is wrapped round insulin-producing cells taken from pigs and injected into patients' bodies. Some sufferers have been 'cured'
Harvesting insulin-producing islet cells from healthy donors and injecting them into the patient's liver, where they start to make insulin.
This involves the harvesting of islet cells, from a healthy donor pancreas and injecting them into patients who cannot produce their own insulin.
The huge quantity of cells needed, around 300,000 per patient, means up to four matching donors have to be found for just one transplant.
An alternative could be the use of so called xenotransplants using organs or cells from animals, such as pigs on humans.
Insulin-producing pig cells are a close match for human ones and are in plentiful supply. But they still get picked up by the body's defense system as a foreign invader.
Now experts at San Diego-based firm MicroIslet Inc have developed the seaweed coating as a potential solution.
Alginate is already widely used in areas such as wound dressings because the body seems to recognize it as friendly rather than foreign.
Millions of pig cells are coated in it before being injected into the abdomen. Once inside the body, they continue to release insulin and there is no need for a anti-rejection drugs.
Mexican researchers are exploring a similar technique where the cells harvested from baby piglets are buried in the body.
The cells are encased in a metal tube that allows insulin to escape, but does not allow immune system cells to get in and destroy the pig tissue.
Scientists behind the experiments claim a number of children have already been cured of their diabetes using this technique.
This research may have huge potential. A major limiting factor in the use of either a whole pancreas or islet cell transplant is the lack of available donor organs.
Transplants of any kind mean a life-time of anti-rejection drugs, however there are serious ethical issues around xenotransplants