Elastic Polydimethylsiloxane Micropillars Seeded With Vascular Muscle Cells

As the research study using mechanics and physics could predict diseases that stress out cells. This discovering a new way to identify; the state of individual cells by bringing principles of mechanical engineering; and physics to bear on processes that are now well understanding at the macro level; but not yet at the cellular level; how stressors such as injury and polydimethylsiloxane micropillars disease force an organism into a new level of equilibrium a biological process of finding a new normal called allostasis.

The researchers findings carry major implications for the diagnosis; and staging of chronic diseases like hypertension and diabetes. By using live cell imaging and a novel micro-mechanical tool to apply a transient, local physical stress on cells while simultaneously measuring dynamic allostatic responses and the tension of the cells’ cytoskeleton (CSK) and other cellular structures, cellular energies.

Energy Mediated Machinery Drives Cellular Mechanical Allostasis;  which will be featuring in Advanced Materials, details how the team measured mechanical stress; and energies of cells and compared the stress patterns to those of cells in patients with chronic conditions like type II diabetes; allowing them to build predictive models for diabetes and other conditions.

Elastic polydimethylsiloxane micropillars

The cells remodeled themselves through mechanical and energy relating processes in response to  external stimuli; the team employing a tweezer developing by Chen that uses ultrasound pulses and microbubbles; that attach to the cell membrane and as the pulses perturb the bubbles exert mechanical forces on the cells. The team embedded the vascular muscle test cells in a substrate comprising elastic polydimethylsiloxane (PDMS) micropillars.

This setup allowed them to quantify cellular force and energy during the operation by measuring deflections of the micropillar substrate; fluorescent microscopy allowed the team to visually monitor how stress reorganized the CSK, especially its constituents actin and myosin that, like metal fibers in a steel-belted radial tire, can become dysfunctional and deformed under force.

Biophysical model of energy

Using experimental results, the team built a new biophysical model of energy-driven cellular machinery for understanding allostasis in cells. In this process, cellular energy not only provides the driving power for adaption; but also a negative feedback to help in restabilizing the cell’s system. A skewed energy pattern and cell maladaptation; may indicate a transformation of healthy condition into a pathological contexts, such as diabetes, hypertension, or aging.

For example, disruption in such cell CSK structures as actin fibers; can result in a weak adaptative process which may reveal pathological condition like diabetes; while over-activity in actin polymerization in cells may cause “prolonged excitation” or hypo reactivity without an “off” time after a perturbation in conditions like hypertension.