The next step in ultrasound imaging will let doctors view specific cells and molecules deeper in the body, such as those associated with tumors or bacteria in our gut. A new study from Caltech outlines how protein engineering techniques might help achieve this milestone. The researchers engineered protein-shelled nanostructures called gas vesicles (which reflect sound waves) to exhibit new properties useful for ultrasound technologies. In the future, these gas vesicles could be administered to a patient to visualize tissues of interest. The modified gas vesicles were shown to give off more distinct signals (making them easier to image), target specific cell types, and help create color ultrasound images.
…In another set of experiments, the researchers demonstrated how the gas vesicles could be made to target certain tissues in the body. They genetically engineered the vesicles to display various cellular targets, such as an amino acid sequence that recognizes proteins called integrins that are overproduced in tumor cells.