A curious hybrid of a red blood cell and an聽E. coli bacterium could make an ideal transporter for carrying drugs inside the body.
Drug treatments often have side effects by causing changes elsewhere in the body, prompting researchers to hunt for clever ways to package drugs and target them more precisely to where they are needed. A previous effort used sperm to carry drugs towards mini tumours in a dish.
Cells of E. coli bacteria are also strong swimmers, with a spinning tail that acts like a propeller. However, these cells are small and don鈥檛 have much room for cargo. Red blood cells, meanwhile, are big and spacious, but can鈥檛 propel themselves.
Advertisement
Metin Sitti and colleagues at the Max Planck Institute for Intelligent Systems in Stuttgart, Germany decided to combine the two. They loaded mouse red blood cells with a cancer drug and magnetic nanoparticles, then chemically stuck them onto E. coli bacteria that had been engineered not to cause disease.
Drugs on demand
These hybrid swimmers reached speeds of around 10 micrometres per second, and were easily steered using magnetic fields. The transporter was able to squeeze through tiny channels only 3 micrometres wide, which shows that they can get to anywhere in the circulatory system, says Sitti.
So that they would release their drug cargo on demand, the microswimmers were injected with a heat-responsive dye. When they reach their target, the team used a flash of radiation to heat them up, causing them to rupture, release the drugs, and die.
If the swimmers are injected close to their target, it might take them a few hours to reach it, says Sitti. The team plans to test their swimmers in rodents next. 鈥淒epending on the results, we can apply in humans in three or four years,鈥� says Sitti.
[video_player id=鈥�0rlJDggh鈥� access_level=鈥漞veryone鈥漖
