Synthetic Microcapsules Mimic Real Cell Behavior

Scientists at the University of Pittsburgh have designed tiny polymer-based microcapsules that are capable of basic communication and cooperation based on signals sent and received between them. These artificial “cells” perform the trick by secreting specific nanoparticles, appropriately called agonists, that trigger certain behavior of other capsules. Once the signal has been processed, the receiving capsules in return can signal a feedback loop by releasing particles called antagonists. The receiving capsules are even able to move thanks to how the released nanoparticles alter the surface beneath them.

The cell’s polymer-based walls begin to push on the fluid surrounding the capsule and the fluid pushes back even harder, moving the capsule. At the same time, the nanoparticles from the signaling cell pull it toward the target cells. Groups of capsules begin to form as the signaling cell rolls along, picking up target cells.

Here are a few videos demonstrating the signaling ability of the microcapsules:

As the signaling cell (right) emits the agonist nanoparticles (shown as blue), the target cell (left) responds with antagonists (shown as red) that stop the first cell from secreting. Once the signaling cell goes dormant, the target cell likewise stops releasing antagonists–which makes the signaling cell start up again. The microcapsules get locked into a cycle that equates to an intercellular conversation, a dialogue humans could control by adjusting the capsules’ permeability and the quantity of nanoparticles they contain.

These are so called trailing “ants,” wherein the particle secretions of one microcapsule group are delayed until another group passes by and activates it. The newly awakened cluster then follows the chemical residue left behind by the lead group.

A “dragon” formation comprising two cooperating signaling cells (shown as red) leading a large group of targets. Similar to these are “snakes” made up of competing signaling capsules pulling respective lines of target cells.
Press release: Pitt Team Designs Artificial Cells That Communicate and Cooperate Like Biological Cells, Follow Each Other Like Ants …
Abstract in Proceedings of National Academy of Sciences: Designing communicating colonies of biomimetic microcapsules