Sneaky molecules unzip when they locate disease

"These types of switchable nanoparticles could be extremely versatile. As well as initial detection of a medical condition, they could be used to monitor the progress of diseases and courses of treatment, or adapted to deliver potent drugs at particular locations in a patient's body," says Cameron Alexander. (Credit: University of Nottingham)

Scientists are testing encapsulated molecules that unzip and spring into action when triggered to do so.

A sheath of biocompatible polymer shrouds the biologically active material inside, preventing any interaction so long as the shield remains in place.

The smart aspect is in the DNA-based zippers that hold the coat in place. Because any DNA code (or “molecular cipher”) can be chosen, the release mechanism can be bar-coded so that it is triggered by a specific biomarker—for example a message from a disease gene.

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What is then exposed—an active pharmaceutical compound, a molecular tag to attach to diseased tissue, or a molecular beacon to signal activation—depends on what function is needed.

“These types of switchable nanoparticles could be extremely versatile. As well as initial detection of a medical condition, they could be used to monitor the progress of diseases and courses of treatment, or adapted to deliver potent drugs at particular locations in a patient’s body,” says Professor Cameron Alexander of the University of Nottingham’s School of Pharmacy, who leads the project.

“It might even become possible to use mobile phones rather than medical scanners to detect programmed responses from later generations of the devices.”

In their initial trials, the team showed the concept works in the test tube—the switchable molecular constructs do respond as expected when presented with the right molecular signals.

An early application might be in dipstick technology—testing for specific infections in a blood or spit sample, for example.

But because the polymer coating (called polyethylene glycol) is biocompatible, the researchers are hopeful that in the long run “self-authenticating medicines” based on the approach could be injected into patients to seek out diseased tissue and report their success.

The journal Nanoscale published the team’s results. The Engineering and Physical Sciences Research Council funded the project.

Source: University of Nottingham