From active matter to artificial cells: a mechanical insight into the fabric of life

Summary

The goal of the proposed research is to theoretically investigate an artificial cell-like structure to understand how mechanical functionality emerges in living matter. Living cells, from the simple prokaryotes to the more complex eukaryotes, are capable of astonishing mechanical functionalities. They can deform spontaneously or in response to environmental stimuli, move in a fluid or on a substrate and generate enough force to split themselves in two while remaining alive. These unique properties are possible because the building blocks that form the mechanical apparatus of the cell are active: they are able to transform stored or ambient energy into mechanical work. But how does functionality emerge from mechanical activity? In order to address this question I will focus on an artificial cell-like structure consisting of a lipid vesicle enclosing an active liquid crystal that performs the functions of the cytoskeleton and that can be experimentally obtained from purified extracts of cytoskeletal filaments and motor proteins (Fig. 1). Using this active prototype cell (or simply active protocell) as a model system, I will shed light into the complex mechanical properties that characterise the ?fabric of life?, via a challenging theoretical and computational research program.
Building on my expertise in continuum mechanics, liquid crystals, topological defects and geometry, I will investigate: (1) how active and passive forces allow the cell to control and modify its shape; (2) how activity and geometrical confinement can drive cell division in the absence of a regulatory network; (3) how the interactions between the cell and its environment lead to spontaneous motion and how this can be directed by chemical and hydrodynamic cues.
Our endeavours on active protocells will be complementary to the ongoing grand challenge on artificial life and will create a much needed link between the world of artificial cells and theoretical physics.

Details

Project number

680-47-547

Main applicant

Dr. L. Giomi

Affiliated with

Universiteit Leiden, Faculteit der Wiskunde en Natuurwetenschappen, Leids Instituut voor Onderzoek in de Natuurkunde (LION)