“Our invention is the first of its kind that allows drug particles to be directed deep into a tumour in a few milliseconds,” said lead researcher Xu Chenjie, assistant professor at Nanyang Technological University (NTU) in Singapore.
The micro-sized gas bubbles, successfully tested in mice, are first coated with cancer drug particles and iron oxide nanoparticles. Using magnets, these bubbles are then directed to gather around a specific tumour.
Through ultrasound, the micro bubbles are vibrated, which provides them the energy to direct the drug particles into the targeted area.
The drug particles can penetrate a depth of 50 cell layers or more – which is about 200 micrometres, twice the width of a human hair.
“The first unique characteristic of our microbubbles is that they are magnetic. After injecting them into the bloodstream, we are able to gather them around the tumour using magnets and ensure that they don’t kill the healthy cells,” explained Chenjie in the paper published by the Nature Publishing Group in Asia Materials.
The method ensures that the drugs can reach the cancer cells on the surface and also inside the core of the tumour.
Also, it can be a good alternative treatment in the future, which is low cost and yet effective for the treatment of cancers involving solid tumours, as it might minimise the side effects of drugs, the researchers added.
According to the team, the current chemotherapy drugs are largely non-targeted. The drug particles flow in the bloodstream, damaging both healthy and cancerous cells.
These drugs are also typically flushed away quickly in organs such as the lungs and liver, limiting their effectiveness.
The remaining drugs are also unable to penetrate deep into the core of the tumour, leaving some cancer cells alive.
They estimated that it would take another eight to ten years before the method reaches human clinical trials.