Taking cues from slime molds, ants, and living biological cells, a team of University of Pittsburgh researchers has designed a system of artificial cells that can communicate with one another and cooperate to carry out tasks. The computer models they've devised could lead to artificial cellular systems that perform highly specialized jobs at the microscopic level.
The artificial cells are more like microcapsules that can move independently and deposit cargo wherever it's needed. But directing these microcapsules -- or more accurately, getting them to direct themselves -- is the real breakthrough. By secreting special nanoparticles, the microcapsules are able to communicate (video here), assemble into groups (video here), move in tandem, or deposit their cargos just like living cells can. But unlike living cells, the lack the complicated biochemistry that can make living cells so hard to manipulate.
To communicate, a signaling cell will secrete special nanoparticles known as agonists that prompt the target cell to respond by secreting different nanoparticles known as antagonists. When the antagonists reach the original signaling cell, it stops secreting agonists. Once the signaling cell goes silent, the target cell does the same (it was only secreting antagonists in response to the agonists). At that point, the signaling cell knows to start signaling again.