By adapting life's own microscopic machinery, some researchers hope to create minuscule factories that will churn out novel drugs and materials. In that quest, scientists have already commandeered mobile threadlike cell structures called microtubules as potential factory workers. But those wriggly strands have tended to wander aimlessly, preventing any useful work from getting done.
Now, Taro Q.P. Uyeda of the National Institute of Advanced Industrial Science and Technology in Tsukuba, Japan, and his colleagues have devised a novel way to boss microtubules into following one-way paths. The trick is to construct routes with wee trail makers shaped like arrowheads.