Device reveals mechanical behavior of 3D multicellular tissue samples

Everyday physical cues experienced by cells in the human body play fundamental roles in regulating their behavior. Whereas previous research on the topic has often focused on isolated single cells grown on 2D surfaces, Walker et al. took this one step further by creating a microfabricated vacuum actuated stretcher to study the straining and relaxation of 3D multicellular samples.

“We contributed a device and methodological approach that allows us to study how a group of hundreds of cells growing as 3D ‘micro-tissues’ change their properties in response to stretching, while also being able to visualize the responses at the single cell-level,” said author Andrew Pelling.

This research provides information on not only the mechanical phenomena that lead to the deformation of cells, but also how external forces govern the biological behavior of cells.

It has been understood that cells possess the ability to both store mechanical energy like an elastic solid and dissipate energy like a viscous fluid. However, contrary to the existing understanding of the mechanics of single cells, the authors found that large groups of cells relieve and recover mechanical forces over time with a fundamentally different behavior.

Looking forward, the authors hope that their device can be used to study the effects of cytoskeletal mutations, and as a screening platform to assess how living tissues are degraded by pharmacological agents, genetic mutations or environmental stimuli.

“We are currently collaborating with the Children’s Hospital of Philadelphia to investigate the role tissue mechanics plays in visceral myopathies such as chronic intestinal pseudo-obstruction and megacystis microcolon intestinal hypoperistalsis syndromes,” said Pelling.

Source: “Time dependent stress relaxation and recovery in mechanically strained 3D microtissues,” by Matthew Walker, Michel Godin, James L. Harden, and Andrew E. Pelling, APL Bioengineering (2020). The article can be accessed at https://doi.org/10.1063/5.0002898 .