A synthetic pore that lets sodium cross imitation cell membranes is 'a significant step towards tissue-mimetic materials,' say UK scientists.

Scientists at the University of Manchester have synthesised channels in vesicles - synthetic cell mimics - which open and close when palladium(II) ions are added or removed. The open channels span the vesicles' lipid outer membrane to allow sodium into or out of the structure.

Adding palladium ions opens a channel in a synthetic cell membrane to allow sodium ions through

The channel imitates ligand gated ion channels in nature. These channels are regulated by molecular messengers that bind to the pore protein to either open or close it. 

Simon Webb, who worked on the channel with Craig Wilson, says that 'one of our primary research themes is the construction of biomimetic materials that can replicate tissue structure and function.' He explains that while the production of synthetic mimics of other types of ion channel has progressed rapidly, 'ligand gated ion channels such as this, have remained a challenge.'

The basic skeleton of the new synthetic channel is easy to make from commercially available chemicals and can readily be modified to study the effects of a broad range of different ligands. Webb plans to exploit this property to synthesise channels that are gated by bacterial signalling molecules that can be used to develop and study antibiotics that will block these molecules.

Scott Cockroft from the University of Edinburgh, UK, is interested in using ion channels for physical experiments. He says that 'synthetic ligand gated ion channels have the potential to find applications in all manner of advanced materials. Perhaps one day they might even serve as components within completely synthetic biological systems.' 

Webb agrees and says that his ultimate aim is to create ligand gated channels that can form a pore between two vesicles to mimic the cell-cell adhesion in real tissues. 

Laura Howes