DNA Tinker Toys

Dendrimers are star-like molecules that can carry drugs or biological markers on their different arms.  They can be engineered to deliver their payload to a specific target - say, a tumor cell.

Producing these drug-delivery systems is long and difficult.  But recently, researchers at the University of Michigan have used strands of DNA to increase the speed and efficiency of the manufacture of dendrimer complexes.

Because DNA strands have a specific code, they can control what attaches to what in specially formulated solutions.

In a preliminary experiment, Youngseon Choi, a graduate student, took a solution of two different dendrimers and employed short pieces of DNA to connect them.  The resulting barbell is pictured in the illustration above, where one of the dendrimers (yellow) is shown in the background docking with the wall of a tumor cell.

In a cancer therapy scenario, the non-docking dendrimer (green) might carry a poison that would kill the targeted cell.

James R. Baker, Choi's adviser, plans to develop a library of dendrimers that can be linked together with DNA to perform a wide variety of tasks.

"So it's like having a shelf full of Tinker Toys," Baker said.

A paper describing these results was published in the Jan. 21 issue of Chemistry and Biology. 

-- Michael Schirber

Credit: Michigan Center for Biologic Nanotechnology