Self-assembling medicine-delivery cubes

Researchers at Johns Hopkins University created tiny perforated cubes the size of dust specks that self-assemble. The idea is to load the metallic cubes with medications or living cells like those used in certain therapies. Then, magnets might be used to guide the through the body to a specific site where their cargoes could then be released. From a press release:

 Images Release Graphics Jhu121205 1To make the self-assembling containers, (researcher David) Gracias and his colleagues begin with some of the same techniques used to make microelectronic circuits: thin film deposition, photolithography and electrodeposition. These methods produce a flat pattern of six squares, in a shape resembling a cross. Each square, made of copper or nickel, has small openings etched into it, so that it eventually will allow medicine or therapeutic cells to pass through.

The researchers use metallic solder to form hinges along the edges between adjoining squares. When the flat shapes are heated briefly in a lab solution, the metallic hinges melt. High surface tension in the liquified solder pulls each pair of adjoining squares together like a swinging door. When the process is completed, they form a perforated cube. When the solution is cooled, the solder hardens again, and the containers remain in their box-like shape.

"To make sure it folds itself exactly into a cube, we have to engineer the hinges very precisely," Gracias said. "The self-assembly technique allows us to make a large number of these microcontainers at the same time and at a relatively low cost."

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