Researchers are working on ‘optical tweezers’, which use the force of light for biomedical research.

The inventors of the ground-breaking laser technology were awarded the 2018 Nobel Prize in physics. The device is being used in biology, medicine and materials science to assemble and manipulate nanoparticles such as gold atoms. However, the technology relies on a difference in the refractive properties of the trapped particle and the surrounding environment.

Now, scientists have discovered a new technique that allows them to manipulate particles that have the same refractive properties as the background environment, overcoming a fundamental technical challenge.

“This breakthrough has huge potential, particularly in fields such as medicine,” says leading co-author Dr Fan Wang from the University of Technology Sydney (UTS).

“The ability to push, pull and measure the forces of microscopic objects inside cells, such as strands of DNA or intracellular enzymes, could lead to advances in understanding and treating many different diseases such as diabetes or cancer.

“Traditional mechanical micro-probes used to manipulate cells are invasive, and the positioning resolution is low. They can only measure things like the stiffness of a cell membrane, not the force of molecular motor proteins inside a cell,” he says.

Dr Peter Reece, from the University of New South Wales, says the latest research is a significant advancement in a field that is becoming increasingly sophisticated for biological researchers.

“The prospect of developing a highly-efficient nanoscale force probe is very exciting. The hope is that the force probe can be labelled to target intracellular structures and organelles, enabling the optical manipulation of these intracellular structures,” he said.

Fellow researcher Professor Dayong Jin says this work opens up new opportunities for super resolution functional imaging of intracellular biomechanics.

“IBMD research is focused on the translation of advances in photonics and material technology into biomedical  applications, and this type of technology development is well aligned to this vision,” Professor Jin says.

“Once we have answered the fundamental science questions and discovered new mechanisms of photonics and material science, we then move to apply them. 

“This new advance will allow us to use lower-power and less-invasive ways to trap nanoscopic objects, such as live cells and intracellular compartments, for high precision manipulation and nanoscale biomechanics measurement.”