Researchers have developed a new tool that could evaluate new drugs for diseases associated with abnormal levels of cell strength, such as asthma, hypertension and muscular dystrophy.

According to the researchers, the tool named "fluorescently labeled elastomeric contractible surfaces" (FLECS) can measure the physical strength of individual cells 100 times faster than current technologies. "Our new experimental platforms are capable of screening millions of molecules to identify the best drug candidates for the right patients," said co-author of the study, Reynold A. Panettieri Jr. Professor at Rutgers Robert Wood Johnson Medical School in the US.

"FLECS" key component is a flexible rectangular plate with more than 100,000 uniformly spaced X-shaped micropatterns of proteins that are sticky so cells settle on and attach to them. The X's embedded in the plate are elastic, so they shrink when the cells contract. The X's are made fluorescent with a molecular marker to enable imaging and quantification of how much the shapes shrink.

For the study, published in the journal Nature Biomedical Engineering, researchers analysed drugs that make cells either contract or relax, using human smooth muscle cells that line airways in the body -- in effect, simulating an asthma attack in the lab. The researchers compared the results of those tests to what was already known about how lung tissue reacts to the drugs and found that "FLECS" captured the same types of reactions -- only more precisely because it could analyse the reactions in cell-by-cell detail.

The researchers also conducted an additional experiment where they tested the force of macrophages, cells in the immune system that rid the body of potentially harmful particles, bacteria and dead cells. They found that when a typical macrophage receives a signal that an infection is present, it can exert force approximately 200,000 times its own weight in water. "Our tool tracks how much force individual cells exert over time, and how they react when they are exposed to different compounds or drugs," said Dino Di Carlo, Professor of bioengineering at the University of California, Los Angeles.