The MIT Technology Review has an interesting article about ongoing progress at the Mayo Clinic to develop an artificial liver–liver “dialysis” machine–using clusters of porcine hepatocytes. The Mayo machine is loaded with 200 grams of freshly isolated pig hepatocytes, which is about 20% of liver mass of normal human liver. The research is being conducted by a group of associates led by Scott L. Nyberg M.D., Ph.D.
From the article:
The Mayo liver device looks vaguely like a fish tank set on a cantilevering metal platform. The reservoir is filled with a highly oxygenated liquid medium into which Nyberg deposits up to 500 grams of live pig hepatocytes. Blood from the patient first courses through membranes that separate red cells and plasma from the larger white blood cells.
The plasma and smaller blood cells continue on their circuit into a tube immersed in the liquid suspension of clustered pig cells. The pore size of the tube’s membrane allows blood to flow in and out of the hollow fiber while the hepatocytes remove bile, ammonia, urea, and other impurities. The pore size also blocks the hepatocytes and any pig cell debris from entering the patient’s blood.
The machine uses a rocking motion — 15 seesaws per minute — to bathe the liver cells in nutrients so they can survive longer and function better. In the dog tests, Nyberg says, the cells remained fully active in the reservoir for 48 straight hours of blood detoxification. He says he’s kept pig liver cells metabolically viable in the device for up to a month, and sees no reason why humans could not be kept alive while attached to the device for at least that long.
To read more, go straight to the article or visit Dr. Nyberg’s lab…