What look like animated illustrations that could easily spring from a child’s imagination are actually newly unveiled artificial cells under a microscope.
Biophysicists at Germany’s Technical University of Munich along with an international team developed simple self-propelled biomachines in a quest to create cell models that display biomechanical functions.
The researchers say their work represents the first time a movable cytoskeleton membrane has been fabricated.
They did it by making sealed packets of double-layered lipid membranes, like those surrounding real cells. Inside the packets, they inserted microtubules like those that create cellular cytoskeletons and kinesins, the tiny proteins that act like motors and move objects along the cytoskeletons of real cells. At high microtubule concentrations, they were able to coat the entire membrane’s surface with bundles of microtubules that are capable of being stretched out and protruded. They then added adenosine triphosphate, the cellular energy source, to make the system go.
The result is a tunable, shape-changing biomachine that can move through shifting of the microtubules and by growing long projections called filopodia. Their work was published today in the journal Science.
"With our synthetic biomolecular model we have created a novel option for developing minimal cell models," said Andreas Bausch, a TUM biophysicist who worked on the project. “It is ideally suited to increasing the complexity in a modular fashion in order to reconstruct cellular processes like cell migration or cell division in a controlled manner.”
Gifs: Vesicles on the move. The reconstitution of cytoskeletal activity into cell-sized vesicles creates different dynamic shape variations. Forces and activity are produced by kinesins embedded in a nematic cortex of microtubules. All gifs created from movie courtesy of Keber, Loiseau, and Bausch.