Physics of biological and biomimetic systems (PSCVB)

Physics of living systems is approached by using concepts and experimental methods derived from soft matter and by designing model systems that reproduce the complexity of tissues and cells.

Biomimetic prototissues

To study the flow of biological tissues, we design artificial prototissues as model systems through the controlled assembly of giant vesicles. Our biomimetic approach offers the possibility of modulating the mechanical properties of the vesicles as well as their adhesion. The rheological behavior of the prototissues is studied using microfluidics to understand the relationship between cell adhesion and tissue flow.

Figure: A. Microfluidic device designed to assemble giant vesicles and develop prototissues. B. Suction experiment for the rheological characterization of prototissues (the bar corresponds to 100 µm).

Mucociliary function of the bronchial epithelium

We measure the properties of bronchial mucus directly on cultures or samples, combining standard rheometry and microrheology. At the same time, we quantify the coordination of cilia beating and mucus flow on these same tissues from the cilia scale to the tissue scale. We also use simple numerical models of cilia coupled by fluid.

A) Illustration of the structure of the mucus gel, as suggested by our measurements. B) Cell-averaged beat orientation, with the standard deviation of the angle shown on the color scale. Scale bar 100 microns.

Micro-physiology

Very small animals constitute a considerable part of animal biodiversity, but very little is known about their physiology. Nanoindentation makes it possible to observe the mechanical activity of the heart and periodic variations in blood pressure in fish embryos.