A new family of organic nanotubes was reported in a recent article in Nature Communications. The group of Sébastien Perrier, in collaboration with Professor Kate Jolliffe at the University of Sydney, have designed cyclic peptide / polymer conjugates that can assemble into tubular structures based on the stacking of the cyclic peptides, and provide a tube with a sub-nm internal diameter. Attached to each of the cyclic peptides are two different types of polymers, which tend to de-mix and form a shell for the tube with two faces, and form Janus nanotubes (after the Roman god Janus who is usually depicted as having two faces, since he looks to the future and the past).

The faces provide two remarkable properties – in the solid state, they could be used to make solid state membranes which can act as molecular ‘sieves’ to separate liquids and gases one molecule at a time. This property is promising for applications such as water purification, water desalination and gas storage. In a solution, they assemble in lipids bilayers, the structure that forms the membrane of cells, and they organise themselves to form pores which allow the passage of molecules of precise sizes. In this state they could be used for the development of new drug systems, by controlling the transport of small molecules or ions inside cells.

Maarten Danial, Carmen My-Nhi Tran, Philip G. Young, Sébastien Perrier & Katrina A. Jolliffe, Janus cyclic peptide–polymer nanotubes, Nature Communications 4, doi:10.1038/ncomms3780

Link to the article: http://www.nature.com/ncomms/2013/131113/ncomms3780/full/ncomms3780.html

Link to the Press release: http://tinyurl.com/kjbvlqk