Boston researchers are delving into the physical forces at work in the cell and building a new field along the way.

Eric Smalley

Biologists in the 1800s studied the body as a mechanical machine. Before long, biochemical, genetic, and molecular approaches came to dominate biology. Now Boston-area scientists are updating this mechanical view and helping to forge a new and growing discipline: biomechanics at the cellular and molecular level.

Using powerful technologies to observe and model cells and molecules, scientists are discovering that mechanical forces—the pushing, pulling, and squeezing of cells and tissues—play a surprisingly large role in biology.

“There’s an entire mechanical signaling pathway—the transmission of forces through tissues, cells, and molecules—that parallels the biochemical signaling pathways that molecular biologists have been studying for years,” says Roger Kamm, a mechanical engineering and biological engineering professor at MIT. “Biologists typically haven’t fully appreciated the role of mechanics until relatively recent times,” he says.

Mechanical forces turn out to affect cell growth, division, migration, and death. They also regulate tissue development and even gene activity. For example, the contraction of protein skeletons inside embryonic lung cells stimulates lung development. When cells stretch, ion channels in their membranes open or close.

Under the cell’s hood

This research is coalescing into a field dubbed mechanobiology. Kamm is co-hosting an invitation-only summit of biomechanics researchers scheduled for next month in Colorado that is charged with laying out a research agenda for the field for the next 10 years. Mechanobiology is one of the summit’s main focuses.

Thanks to technologies like computer simulations and fluorescence microscopy, biomechanics researchers have found that natural forces affect biochemical activity in the cell by physically changing the structures of cells and molecules and hence how they interact with each other. For instance, forces can change the shape of a protein molecule, which in turn can alter its ability to bind to another molecule.

“The same chemical signal or gene activity produces entirely different biological effects in a different mechanical environment,” says Donald Ingber, a vascular biology professor at Children’s Hospital Boston and Harvard Medical School and a pioneer in mechanobiology.

Mechanical medicine

The main goal for the field is to figure out how the mechanical and biochemical signaling pathways interact and how those interactions can be controlled for therapeutic applications, says Kamm.

Researchers are increasingly linking mechanical forces at the cellular level to a wide range of diseases including cancer, heart failure, stroke, rheumatoid arthritis, asthma, and glaucoma, says Ingber.

For some diseases, like lung inflammation, changes in cell mechanics are thought to be a causal factor, so new drugs could target specific cellular components that affect cells’ physical properties.

Because mechanical changes in cells can also occur as a result of certain disease processes, such as cancer, measuring these changes could be the basis for a new type of diagnostic. “I think we’ll see new diagnostic methods that measure the mechanical properties of cells,” says Kamm.