Making nanoparticles in artificial cells( This release is available in A HREF ...),Health

Two new construction manuals are now available for the world's smallest lamps. Based on these protocols, scientists from the Max Planck Institute of Colloids and Interfaces have tailor-made nanoparticles that can be used as position lights on cell proteins and, possibly in the future as well, as light sources for display screens or for optical information technology. The researchers produced cadmium sulphide particles in microscopically small membrane bubbles. Depending on which of the construction manuals they follow, the particles can be 4 or 50 nanometres in size. Because the membrane bubbles have the same size as living cells, the scientists' work also provides an indication as to how nanostructures could arise in nature. (Small, published online: June 8, 2009/DOI: 10.1002/smll.200900560)

Cells and microorganisms are absolute masters when it comes to working in the smallest possible dimensions. Like particularly efficient micro-factories, they produce particles and structures from inorganic material, for example pieces of chalk, that are only a few nanometres in size, that is, millionths of a millimetre. Cells have two different factors to thank for this capability. First, they have peptides, a biological tool at their disposal that may shape the chalk into a desired form. Second, the fact that they are very small themselves is convenient: the chalk particles cannot grow boundlessly - the end is reached when the calcium carbonate, the building block of chalk, runs out in the cell.

"We used the fact that cells represent a closed reaction container as a model for the synthesis of nanoparticles," says Rumiana Dimova. Her group at the Max Planck Institute of Colloids and Interfaces studies membranes - the cell envelope. The scientist and her colleagues form bubbles that are around 50 micrometres i
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