A device for investigating cell signalling has been invented by bioengineers in the US. The device, prepared by a group headed by Albert Folch at the University of Washington, allows controlled delivery of molecules to individual cells.

The researchers grew muscle cells on a plastic chip and used small holes in the plastic to control the flow of signalling molecules into the cells. In this way they could precisely specify the strength and duration of the cell stimulus. The device can therefore be used to mimic cell-cell signalling, which could be exploited for example to model synapses, the junctions between nerve and muscle cells through which chemical signals are passed.

Folch's group used the device to follow the early stages of formation of these nerve-muscle junctions. They injected a cell signalling factor, agrin, into small regions of the muscle cells and observed the cells' response to the stimulus. Folch suggests that the method represents a great improvement over previous studies of synapse formation. These rely on bathing cells in a solution of agrin, a process that does not accurately represent the conditions in real organisms, he said.

The device need not be limited to studying synapses, said Folch. Since each chip has multiple holes it can be used to perform several experiments at once, or to observe how nearby signals interact, he continued. This device could have wide applications in 'modulating cellular microenvironments in cell biology studies and biotechnology assays,' he said.

Clare E Boothby