Lab-grown steaks nearing the menu
Fancy a beefburger, but want to spare the cow? Tissue engineers experimenting with ways of growing meat in a lab dish could soon provide a solution.
The aim of the work is to develop food for astronauts on long space journeys, such as a mission to Mars. But like much other space research, what happens up there could one day become commonplace down here too - just look what happened to Velcro.
A NASA-funded team led by Morris Benjaminson, at Touro College in New York City, has already taken the first steps. The team removed chunks of live muscle tissue from freshly killed goldfish and raised them in a standard cell-culture fluid for a week. The tissue grew by as much as 14 per cent, thanks to partially differentiated "myoblast" cells in the adult muscle dividing to make more muscle cells, he says.
But growing larger pieces of muscle tissue in the lab will be tricky. The main problem is ensuring a constant supply of nutrients for the growing cell mass. In a tissue fed by a blood supply, the capillaries must be no more than 200 microns apart or else the cells in between become necrotic and the tissue dies.
Although the Touro team developed techniques for growing white and dark chicken muscle in the lab, without a blood supply the chicken meat grew for just two months before it was dead in the dish. Benjaminson is now submitting another NASA proposal to investigate mechanical or electrical methods of stimulating blood vessel growth.
Protein spheres
However, you only need to establish a good blood supply if you want to grow thick slabs of muscle. Vladimir Mironov, director of the Shared Tissue Engineering Laboratory at the Medical University of South Carolina in Charleston has other ideas. His team thinks the meat of the future will be a processed food closer to a sausage or hamburger.
In a detailed project proposal to NASA, he sets out how to grow cells on protein spheres suspended in growth medium. These could then be harvested and made into nuggets or patties.
His starting cells will be myoblasts, which normally live at the edges of muscle fibres and help repair the muscles if they are damaged. They are better suited than embryonic stem cells, Mironov says, because they are already part of the way down the road to forming the desired cell type, rather than being totally undifferentiated.
SD
Mmmmm, I'll have the double-myoblastburger with pasteurized process cheese-food product, fries and a coke.