What powers our heart and lungs decoded

A favourable electrical property is present in a type of protein found in organs that repeatedly stretch and retract such as the lungs, heart and arteries, researchers including one of Indian-origin, say.

PTI| Last Updated: Jun 24, 2014, 20:37 PM IST

Washington: A favourable electrical property is present in a type of protein found in organs that repeatedly stretch and retract such as the lungs, heart and arteries, researchers including one of Indian-origin, say.

Measurements taken at the molecular scale have for the first time confirmed a key property that could improve our knowledge of how the heart and lungs function.

These findings by University of Washington researchers and colleagues are the first that clearly track this phenomenon, called ferroelectricity, occurring at the molecular level in biological tissues.
"We wanted to bring in different experimental techniques, evidence and theoretical understanding of ferroelectricity in biological functions," said Jiangyu Li, a UW professor of mechanical engineering and corresponding author of the paper.

"We certainly have much more confidence now in the phenomenon itself," said Li.

Ferroelectricity is a response to an electric field in which a molecule switches from having a positive to a negative charge.

This switching process in synthetic materials serves as a way to power computer memory chips, display screens and sensors.
This property only recently has been discovered in animal tissues and researchers think it may help build and support healthy connective tissues in mammals.

The study, co-authored by Pradeep Sharma at the University of Houston, proves that ferroelectric switching happens in the biological protein elastin.

When the researchers looked at the base structures within the protein, they saw similar behaviour to the unit cells of solid-state materials, where ferroelectricity is well understood.

The researchers wanted to establish a more concrete, precise way of verifying ferroelectricity in biological tissues.

They used small samples of elastin taken from a pig`s aorta and poled the tissues using an electric field at high temperatures.

They then measured the current with the poling field removed and found that the current switched direction when the poling electric field was switched, a sign of ferroelectricity.

They did the same thing at room temperature using a laser as the heat source, and the current also switched directions.

The research was published in the journal PNAS.