Volume 7 Issue 3, March 2008

Simplification in large-area manufacturing of complex organic electronics is a critical step towards ubiquitous, flexible, portable applications; why not make the molecules do the work?

Peptide-functionalized polymer nanoparticles target and bind to articular cartilage tissue, making them promising drug-delivery vehicles.

The mechanical properties of granular matter are affected by the addition of liquid — however, over a wide range, the actual amount of liquid is unimportant. Now, imaging techniques look inside the wet granular pile, or 'sandcastle', to help solve this puzzle.

The complex electronic properties of alkali-doped fullerides derive from the interplay between competing interactions. Fine control of the doping levels and thickness of fulleride films makes it possible to tune relevant parameters.

Theoretical work has highlighted the potential of using devices in which spin-polarized carries are injected in single molecular magnets, and a few experiments have shown promising results. The challenges are great, but the advantages compared with more conventional strategies may be considerable, and future research promises to be intriguing and rewarding.

Mixing granular materials such as sand with a liquid leads to stiffening, but the mechanical properties are surprisingly independent of the amount of liquid. This phenomenon is shown to result from the particular organization of the liquid into open structures within the granular pile.

The precise mechanism of the insulator-to-metal transition in MnO has been unravelled by a computational approach that shows that the transition is a result of the simultaneous collapse of the magnetic moment.

Controlling and monitoring individual spins is desirable for building spin-based devices. The optical manipulation of the spin of manganese ions in gallium arsenide is now possible. The spins of a small number of ions can be oriented by selecting the polarization of a laser beam. Reduction of the ion concentration enables control of single manganese spins.

Crystallization of acenes into high-mobility structures for transistors is achieved by pretreating the substrate in the region where crystallization is required. Cross-talk is prevented between devices by the amorphous material produced on the untreated region.

A three-step synthetic method that involves silica coating, heat treatment and removal of the silica layer is reported for the preparation of hollow iron oxide nanocapsules. The magnetite nanocapsules made by this simple wrap-bake-peel process show potential as drug-delivery vehicles and MRI contrast agents.

The extracellular matrix of dense, avascular tissues presents a barrier to polymer-based therapeutics, such as drugs encapsulated within polymeric particles. Jeffrey Hubbell and colleagues now show that biomolecular binding of sufficiently small polymer nanoparticles can transform the matrix of cartilage tissue from a barrier into a reservoir, considerably improving the bioavailability of drugs in the matrix.