Researchers have successfully built the simplest artificial cell ever that can navigate using chemicals, much like living cells do.
Chemotaxis is the essential navigation system cells use to find their way, whether it’s bacteria seeking food or white blood cells moving to fight an infection.
Researchers at the Institute for Bioengineering of Catalonia (IBEC) have shown how to program tiny bubbles to follow chemical trails.
The study details the creation of a “minimal cell” that’s essentially a tiny lipid vesicle (a microscopic bubble).
What makes it special is that it encapsulates enzymes and can propel itself using chemotaxis, meaning it actively moves in response to chemical signals.
These lipid vesicles can be programmed to move towards specific substances, mimicking how living cells like bacteria, white blood cells, and even sperm navigate.
‘What we find particularly fascinating is that this type of directed movement can occur even without the complex machinery typically involved, such as flagella or intricate signalling pathways. By recreating it in a minimal synthetic system, we aim to uncover the core principles that make such movement possible,” explained Bárbara Borges Fernandes, a PhD student, and study’s first author.
Artificial cell movement
To accomplish their goal, the researchers observed how cell-like vesicles moved when exposed to varying concentrations of glucose and urea.
They placed either glucose oxidase or urease enzymes inside liposomes (lipid-based vesicles) to transform these substances into their final products.
A crucial step was adding a membrane pore protein to the liposomes.
The enzymes convert specific substances, while the pores act as channels for exchange.
Imagine the liposome as a boat. The pore and the enzyme act as its engine and navigation system, propelling it precisely toward its destination.
This active motion relies on “breaking symmetry.”
Trapping enzymes inside the vesicle and using pores to swap chemicals creates an uneven concentration around the particle.
This slight imbalance then generates a fluid flow that propels the vesicle in a specific direction.
The IBEC team carefully analyzed over 10,000 vesicles.
What they found was remarkable: as the number of pores increased, the artificial cells showed a stronger chemotactic response, moving directly towards higher concentrations of the desired substances.
Understanding cell functioning
Professor Battaglia emphasizes that by simplifying biological systems, like building an artificial cell with just a fatty shell, one enzyme, and a pore, researchers can uncover the fundamental principles of cellular communication and transport.
He sees this minimalist approach, inherent to synthetic biology, as a way to reveal the elegant, underlying chemistry that drives complex biological processes.
“These synthetic cells are like blueprints for nature’s navigation system. Build simple, understand profoundly,” said Battaglia, ICREA Research Professor at IBEC, Principal Investigator of the Molecular Bionics Group, and leader of the study.
The study is not just a scientific curiosity.
The ability to engineer artificial cells provides insights into how early, simple cellular units might have evolved into the complex life forms we see today.
The findings were published in the journal Science Advances