12-02 :: February/March 2012

nanotimes News in Brief

cles within slightly larger vesicles. This “Russian doll” structure mimics the organization of cell compartments. Reproducing it is a first major step towards triggering controlled reactions within the structure of the cell. Over the last 10 years, the team coordinated by Sébastien Lecommandoux has been developing “intelligent” polymersomes from polypeptides whose properties and structures are analogous to those of viruses.

The researchers are now taking this biological mimicry and inspiration further, by encapsulating polymersomes within each other. This compart- mentalization mimics the structure of cells, which are themselves composed of compartments (small internal organelles, where thousands of interactions and reactions take place everyday) and a viscoelas- tic cytoplasm, providing the cell with a degree of mechanical stability. However, forming such encap- sulated polymersomes in a controlled manner is no mean feat.

The researchers are the first to have achieved this type of multiple, controlled encapsulation in com- partmentalized vesicles, especially polymers, that also mimic the cytoskeleton, thus reproducing the structure of the cell in its entirety. The next step will be to use this system to trigger controlled chemical reactions in attoliter volumes (10-18 liters), in a confined environment.

Maïté Marguet, Lise Edembe, Sébastien Lecommandoux: Polymersomes in polymersomes: multiple loading and permeability tuning, In: Angewandte Chemie Internatio- nal Edition, Volume 51(2012), Issue 5, January 27, 2012, Pages 1173-1176, DOI:10.1002/anie.201106410: http://dx.doi.org/10.1002/anie.201106410

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Top, encapsulation of two types of internal polymersome populations, one in green and the other in red. Bottom, encapsulation in all the possible compartments: external membrane (blue), cavity of the external polymersome (green), internal polymersomes (red). © Organic Polymer Chemistry Laboratory (CNRS/ Bordeaux 1 University/ Polytechnic Institute of Bordeaux)

At the Micro and Nano Laboratory in Gaustadbek- kdalen in Oslo, scientists have created one of the most advanced radiation sensors in the world: an X-ray detector that can reveal the composition of materials in a fraction of a second. The sensor has been developed by SINTEF nanotechnologists, and is already an exclusive component in great demand by industries that supply advanced analytical instru- ments for materials science. This type of sensor is known as a silicon drift diode (SDD), and it is the basic component of a number of instruments that