Taking ultrasound to the molecular level

Ultrasound could be used to image cells and molecules deep inside the human body thanks to developments in protein engineering at Caltech in the US.

The researchers are said to have engineered protein-shelled nanostructures called gas vesicles - which reflect sound waves - to exhibit new properties useful for ultrasound technologies.

The modified gas vesicles were shown to give off more distinct signals, making them easier to image; target specific cell types; and help create colour ultrasound images. In the future, they could be administered to a patient to visualize tissues of interest.

"It's somewhat like engineering with molecular Legos," said Mikhail Shapiro, an assistant professor of chemical engineering and senior author of a new paper about the research published in ACS Nano. "We can swap different protein 'pieces' on the surface of gas vesicles to alter their targeting properties and to visualise multiple molecules in different colours."