Bengaluru, India: Researchers at the Indian Institute of Science (IISc) have uncovered an important scientific mechanism that explains why epithelial tissues—the protective layers covering organs and body surfaces—display glass-like behaviour even though the cells within them remain highly active. The discovery resolves a decades-old puzzle in biology and could significantly improve our understanding of tissue development, wound healing, and cancer progression.
A Biological Mystery Finally Explained
In physics, glass is known for its slow internal movement despite appearing solid. Surprisingly, scientists have observed similar slow-motion dynamics in epithelial tissues, where densely packed cells behave as though they are trapped in a glass-like state. This was difficult to explain because living cells constantly consume energy, move, divide, and communicate, making such sluggish behaviour seem unlikely.
The IISc research team has now shown that the answer lies not in crowding alone but in the combination of cell density and mechanochemical feedback—the continuous interaction between mechanical forces and biochemical signals inside tissues. Together, these processes allow cells to remain biologically active while the tissue as a whole exhibits slow, glass-like dynamics.
Beyond Cell Crowding
Earlier theories suggested that tightly packed cells were enough to produce glass-like behaviour. However, the IISc researchers demonstrated that crowding by itself cannot fully explain the phenomenon.
Their experiments revealed that changes in cell shape, driven by the actomyosin network—the molecular machinery responsible for generating force inside cells—create a feedback loop that stabilizes the tissue. This feedback counteracts the fluidizing effects of cell division and enables the tissue to behave like an active glass even under normal biological conditions.
A New View of Living Tissues
The researchers combined laboratory experiments with advanced computational modelling to recreate the behaviour of epithelial cell layers. Their simulations matched real biological observations and revealed how neighbouring cells continuously exchange mechanical information.
The study also identified collective mechanochemical oscillations, showing that groups of cells coordinate their behaviour through biochemical communication. This finding highlights that tissues are not simply collections of independent cells but highly organized systems capable of synchronized responses.
Why the Discovery Matters
Understanding how epithelial tissues transition between fluid-like and glass-like states has broad implications for medicine and biology.
The findings could help scientists better understand:
- How wounds heal after injury.
- How embryos develop complex organs.
- Why cancer cells sometimes escape from tightly packed tissues to spread throughout the body.
- How tissue mechanics influence disease progression and regeneration.
Improved knowledge of these processes may eventually contribute to new therapies for cancer, regenerative medicine, and tissue engineering.
Advancing the Science of Active Matter
The research bridges the fields of biology and condensed matter physics by showing how living tissues can exhibit properties similar to non-living materials while remaining biologically active.
Instead of viewing glass-like behaviour as a sign of inactivity, the study reveals that living tissues achieve this state through coordinated communication between cells and continuous mechanical regulation. This insight reshapes existing theories about active matter and opens new directions for interdisciplinary research.
A Milestone for Indian Science
The IISc team’s work represents a major contribution to global research on tissue mechanics. By resolving a long-standing scientific paradox, the study strengthens India’s growing reputation in advanced biological physics and biomedical engineering.
As scientists continue exploring how physical forces shape living systems, this discovery provides a powerful framework for understanding the hidden principles governing life at the cellular level.