Micro-machines journey inside animal for first time
It really is a case of science fiction meets reality; microscopic “machines” have travelled inside a living animal for the first time. The small devices delivered a cargo of nano-particles into the stomach lining of a mouse. The research conducted by scientists at the University of California has been published in the journal ACS Nano. Medical applications for micro-machines include the release of drugs into key locations within the body. However, up till now, they have only been tested in laboratory cell samples. Wei Gao and colleagues from UC, Berkeley, fed the little motors to mice. The machines are constructed of polymer tubes coated with zinc, are simply 20 micrometres in length – which is the width of a strand of a human hair.
In the stomach acid, the zinc reacts to produce bubbles of hydrogen, this propels the machines into the stomach lining and then they attach. When the machines dissolve, they send their cargoes into the stomach tissue. The researchers behind this have stated that this method could provide a much more efficient way to deliver drugs directly to the stomach, to treat peptic ulcers and various other conditions. In the paper, they make the suggestion that further work is required in order to “further evaluate the performance and functionalities of various man-made micro-motors in living organisms. This study represents the very first step toward such a goal”. The concept of molecular-scale surgery is able to be traced back to a lecture by celebrated physicist Richard Feynman in 1959 named There is Plenty of Room at the Bottom.
He explained in a talk to the American Physical Society (APS); “Although it is a very wild idea, it would be interesting in surgery if you could swallow the surgeon. You put the mechanical surgeon inside the blood vessel and it goes into the heart and ‘looks’ around. It finds out which valve is the faulty one and takes a little knife and slices it out.” The overall concept has been played out in science fiction, most famously in the cult classic Fantastic Voyage. However, in this case, miniaturised humans journeyed inside the human body rather than tiny machines.