Opto-acoustics is a rapidly developing, non-invasive technique for three-dimensional imaging in tissue with relatively high penetration depth, in some cases in the centimetre range. Optoacoustic methods use the ingenious principle of “listening to light”: Weak laser pulses minimally warm the target tissue, which leads to its temporary expansion. The subsequent tissue relaxation creates ultrasonic signals that the scientists acquire with appropriate sensors and “translate” them into three-dimensional images.
However, certain approaches and applications require additional so-called labels; namely molecules that facilitate to see the desired target structures or physiological processes in the tissue. For Opto-acoustics such labels would provide heating and ultrasound creation only to those regions where the labels are present. For example labels can be targeted to cell relevant for medical-research and thus rendering these cells “audible” for Opto-acoustics.
With high throughput towards new labels
“However, there are still relatively few of these labels available so far,” says Andre Stiel. “This is primarily due to the fact that we are working with a very new method here.” He and his team now want to change this with the project ‘Sorting Sounds – A high throughput microfluidic screening platform for the development of genetically coded labels for opto-acoustic imaging‘.
“Our goal is to develop and construct a high-throughput cytometer for opto-acoustics that is capable of very rapidly analysing and sorting numerous molecules for their suitability as labels. This means to measure the strength of the emitted ultrasound for each molecule,” explains Stiel. “We are additionally going to attempt the modification of existing molecules, such as those from fluorescence microscopy, for opto-acoustics.”
The scientists are planning to provide a future toolbox of signal molecules for opto-acoustic imaging in order to enable a wide range of applications answering urgent scientific questions directly in the target tissue. This would not only benefit basic research of physiological processes, but also extends towards question of pathophysiology of diseases including cancer, chronic inflammation and metabolic diseases.