Researchers from the Jawaharlal Nehru Center for Advanced Scientific Research (JNCASR), an autonomous institute of the Department of Science and Technology (DST), and the Indian Institute of Science (IISc) have discovered that the mechanism that helps activate particles of matter such as tissues and bacterial colonies escape transformation into glass, can facilitate the study of cancerous metastases.
When a liquid is supercooled, the particles in the liquid slow down dramatically, and by lowering the temperature further, the molecules stop moving altogether and turn into glass. Pragya Arora, Prof. Rajesh Ganapathy of JNCASR and Prof. Ajay K Sood of IISc, who studied the glassy dynamics of an artificial active matter system, found that patterns can form in systems made of elongated particles active ingredients that help it avoid becoming glassy.
Their research published in the journal Physical Review Letters showed that the patterns were triggered by defects in particle orientation, which helped keep the particles moving, preventing the system from behaving like typical glass. They have now identified the mechanism that helps these particles of active material, where the individual constituents are elongated, to avoid becoming glassy. This mechanism that helps active systems escape transformation into glass may facilitate the study of cancerous metastases.
“Assemblies of active elongated particles spontaneously merge into beautiful swirls, a technique that prevents them from congealing in the glass. Swirls are mediated by flaws in the packaging. Since these mobile defects are known to play a role in defending the human body against abnormal precancerous cells, this study could provide a tool to probe cancer metastasis,” the researchers said.
“In an effort to develop well-controlled experiments with a synthetic active material where the activity can be systematically tuned while keeping the shape characteristics of the particles fixed, the JNCASR team chose a vibrated pellet system for their experiment. They used millimeter-sized ellipsoidal particles made by 3D printing, made self-propelled by vertical vibrations. Researchers had found in previous studies that particles with asymmetry in shape, mass, and/or coefficient of friction along both ends would become active or self-propelled under vibration,” DST said.
“Building on these results, they created particles with one end rougher than the other to accommodate differences in friction. They also included a hole in the printing process to increase the mass asymmetry between the two sides and tuned the activity of the particles by altering its center of mass by playing with the position of the hole. Arora and his colleagues found that at higher particle densities, most active particles spontaneously coalesce into vortices.” , he added.
According to Arora, cellular systems have several biological functions, such as cell death, extrusion, tissue regeneration, and sorting, which exhibit active behavior. This study can shed light on these fundamental biological processes where these motile defects are critical players.