When fighting cancerous tumors, all too often the very drugs that can destroy a lesion tend to have significant negative effects on the rest of the body. Doses have to be maintained at moderate levels to avoid side-effects that are even worse than the disease. In light of this, researchers have been trying to develop ways to more precisely deliver cancer drugs so that they target where they are needed.
An exciting new approach, which involves using microbubbles to deliver drugs directly to tumors, has shown significant promise thanks to researchers at the University of Leeds in England. A team there has now shown that they can load microbubbles with a cancer drug, attach antibodies to it that seek out a growth hormone associated with blood tumor vasculature, and deliver the drug to specific locations. The microbubbles that were used are about half the size of red blood cells. When at the target, ultrasound was used to break up the microbubbles and release the therapeutic agent within.
So far this has been tried in laboratory animals, but the researchers believe that human clinical trials will help to translate this technology into practice.
“One of the big problems with cancer drugs is that they are highly toxic to the rest of the body too,” said Dr. Nicola Ingram of the School of Medicine at the University of Leeds, one of the leaders of the research. “Microbubble technology could allow us to use these very powerful drugs with precision and that reduces the risk of the drug damaging healthy cells nearby. It is about finely focused drug delivery.”
In addition to better targeting, the researchers also noted that the microbubbles with the drug attached stayed within the circulatory system much longer than when the drug was naked. This allowed for even greater concentrations to gather at the tumors, improving the efficacy of the treatment and allowing for even lower dosing.
“The results of this study are exciting because we not only show the very precise and targeted way microbubbles can be guided to cancer sites but that the efficacy of drug delivery is substantially improved, opening the way to use highly toxic drugs to fight cancer, without the harmful side effects,” added Professor Stephen Evans, head of the Molecular and Nanoscale Physics Group at Leeds and one of the paper’s authors. “Put simply: you get more bang for your buck.”
Here’s Professor Steve Evans at the University of Leeds explaining the research further:
Study in journal Theranostics: Ultrasound-triggered therapeutic microbubbles enhance the efficacy of cytotoxic drugs by increasing circulation and tumor drug accumulation and limiting bioavailability and toxicity in normal tissues
Via: University of Leeds