Artificial cells reveal how living ones take shape

A team of researchers led by Makito Miyazaki from the RIKEN Center for Integrative Medical Sciences in Japan has successfully used artificial cells to unravel the fundamental physical principles governing how living cells shape themselves. Through a combination of experiments, computer simulations, and theoretical analysis, the scientists demonstrated how actin cytoskeleton—the protein network providing cellular structure—can generate shape changes and front-rear polarity without complex biochemical signaling.

Published in Science Advances, the findings offer insights into biological processes such as cell migration, cell division, and embryonic development. The research also paves the way for advancing the development of artificial cells for applications ranging from drug discovery to regenerative medicine and synthetic biology.

Using liposomes—cell-like structures that simulate cell membranes without cellular machinery—the researchers created an artificial cell system encapsulating purified actin cytoskeletal proteins. This minimal, precisely controlled model allowed them to investigate how the cell membrane changes shape, a task impossible in living cells due to their complexity.

The key breakthrough came when the team manipulated the artificial cells physically, consistently observing the spontaneous formation of a single membrane bleb—bubble-like protrusions at the cell's front that direct migration. This demonstrated that front-rear polarity in cells can emerge from simple mechanical properties of the actin cytoskeleton alone, without the need for biochemical signaling or pre-existing asymmetry.

As Miyazaki explains, "By reconstructing membrane morphogenesis from purified proteins, we showed that local interactions within the actin cytoskeleton are sufficient to generate large-scale changes in cell shape." The study not only unearths basic cellular mechanisms but also provides a foundation for future technologies, potentially enabling programmable microscopic systems for sensing, drug delivery, compound manufacturing, and tissue repair.

Miyazaki emphasizes, "By identifying the physical rules that govern cell shape, the present study lays important groundwork for numerous future applications." The team is now focusing on recreating more complex cellular behaviors, bringing artificial cells closer to practical uses in medicine, biotechnology, and synthetic biology.