Nano-Spies Make Light Work of Disease Detection

A world of cloak-and-dagger pharmaceuticals has come a step closer with the development of stealth compounds programmed to spring into action when they receive the signal.

Researchers at the University of Nottingham’s School of Pharmacy have designed and tested large molecular complexes that will reveal their true identity only when they’ve reached their intended target.

The compounds have been developed as part of a five-year programme funded by the Engineering and Physical Sciences Research Council (EPSRC) called “Bar-Coded Materials”.

The cloak each spherical complex wears is a sheath of biocompatible polymer that encapsulates and shrouds biologically active material inside, preventing any biological interaction so long as the shield remains in place.

The smart aspect is in the DNA-based zips that hold the coat in place until triggered to undo. 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.

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.

Professor Cameron Alexander, who leads the project, says: “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. It might even become possible to use mobile phones rather than medical scanners to detect programmed responses from later generations of the devices.”