Ames (Iowa) Laboratory researchers have developed a porous silica nanosphere that can be taken up by a cell and deliver a payload into it on command. The nanospheres are roughly the size of a virus, so they won't trigger an immune response in the body.

The spheres have thousands of parallel channels running completely through them. The spheres soak up molecules of the drug to be delivered. When the channels are filled, the ends of channels are capped to safely seal the drug inside. The caps can be made of magnetic material, so that using a strong magnet externally, the spheres can be opened inside the cells, releasing their contents.

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