Advances in drug delivery

Micromotors unload antibiotics before dissolving in the stomach’s acid. They have been tested successfully in mice and may someday help deliver drugs to humans with fewer side effects than current methods. (Image provided)

For a long time, our advances in human health and ever-increasing life expectancy have come from both improved health practices (such as washing hands) and from creating new drugs to help combat diseases. Of course, there are many diseases which we have still been unable to tame with conventional drugs. Many types of cancer evidence this fact.

There has been plenty of focus on making new drugs, but in recent times there has also been a focus on drug delivery. The idea is a simple one: if you can make a targeted delivery of drugs to a specific region, you can reduce the harm any drug does, thus in a sense also increasing the benefit. It is here where cancer provides a great example. Imagine if, rather than trying to kill cancer cells with radiation or chemotherapy, both of which kill many healthy cells in the process, could we simply deliver a toxic drug to only the cancer cells, leaving the healthy cells in place?

This is only one potential benefit of targeted drug delivery, but thus far the idea has proven somewhat difficult in practice. There have been many ideas about how to make it work but the use of micromoters has been shown to have great potential.

Some nanoengineers at the University of California San Diego have been able to put these tiny machines to work in order to attack a bacterial infection in the stomach. The micromoters are truly microscopic; they are about half the width of a human hair. The motors were able to raise the pH levels in the area of drug delivery (drugs typically work better at certain pH levels) and then release their load of antibiotics.

Of course, these micromoters are not your typical machines, as can be seen in the figure; they are specially designed to be effective inside the body. These micromoters also dissolve readily in the stomach acid, without producing any harmful material.

While this successful test was only carried out in mice, it holds great promise for human use as well. Perhaps we can imagine a time in the near future where no disease can hide from our medicine.