A new ‘Trojan horse’ anti-cancer drug disguises itself as fat.
Scientists say that the “promising” method delivers chemo drug straight into tumours – with fewer side effects.
They explained that the stealthy new drug-delivery system disguises chemotherapeutics as fat in order to outsmart, penetrate and destroy tumours.
Thinking the drugs are “tasty” fats, tumours invite the drug inside.
Once there, the targeted drug activates, immediately suppressing tumour growth.
The drug is also lower in toxicity than current chemotherapy drugs, leading to fewer side effects.
Study leader Professor Nathan Gianneschi, of Northwestern University in the United States, said: “It’s like a Trojan horse.
“It looks like a nice little fatty acid, so the tumour’s receptors see it and invite it in.
“Then the drug starts getting metabolised and kills the tumour cells.”
To develop the targeting system, Prof Gianneschi and his team engineered a long-chain fatty acid with two binding sites – able to attach to drugs – on each end.
The fatty acid and its “hitchhiking” drugs are then hidden inside human serum albumin (HSA), which carries molecules, including fats, throughout the body.
The researchers explained that the body’s cellular receptors recognise the fats and proteins supplied by the HSA and allow them inside.
Quick-growing and hungry, cancer cells consume the nutrients much faster than normal cells. When the cancer cells metabolise the hidden drug, they die.
Prof Gianneschi said: “It’s like the fatty acid has a hand on both ends: one can grab onto the drug and one can grab onto proteins.
“The idea is to disguise drugs as fats so that they get into cells and the body is happy to transport them around.”
In the study, the researchers used the drug delivery system to carry a common, approved chemotherapy drug, called paclitaxel, into tumours in a small animal model.
Disguised as fat, the drug entered and completely destroyed the tumours in three types of cancer: bone, pancreatic and colon.
And the researchers also found that they could deliver 20 times the dose of paclitaxel via the new system, compared to two other paclitaxel-based drugs.
But even at such a high quantity, the drug in Prof Gianneschi’s system was still 17 times safer.
He added: “Commonly used small-molecule drugs get into tumours – and other cells.
“They are toxic to tumours but also to humans. Hence, in general, these drugs have horrible side effects.
“Our goal is to increase the amount that gets into a tumour versus into other cells and tissues. That allows us to dose at much higher quantities without side effects, which kills the tumours faster.”
The findings were published in the Journal of the American Chemical Society (JACS).