Desiccated medical supplies could be sent on long space missions, and it should become possible to create cell-based biosensors that detect poisons such as nerve gas. Human cells usually die within seconds without water, however, Potts and his colleague David Helm knew of a photosynthetic bacterium, or cyanobacterium, called Nostoc commune, that can survive such harsh conditions. N. commune lives on exposed rock surfaces, where it dries out often. N. commune survives by surrounding itself with a slimy substance called glycan, according to Potts. It forms a woolly overcoat for the cells.
Researchers think that glycan protects cell membranes, slowing the rate of drying.
Potts and Helm tried to mix purified glycan with human kidney cells and dry them out at room temperature. When they rehydrated the cells after 8 days, half of the cells recovered and started dividing again, said Potts in a meeting of Britain's Society for Experimental Biology in Canterbury a few weeks ago. By applying the techniques we have found in cyanobacteria, we can dry out human cells. It's very exciting. Alan Tunnacliffe of the Institute of Biotechnology at Cambridge University admits surprise at the fact that the cells survived with only glycan to protect them, since it does not get inside the cells.