A team of researchers at the Technical University of Catalonia (UPC) in Spain have studied the use of gold nanoparticles to detect and treat cancer.
Team leader Romain Quidant, an ICREA researcher at the UPC's Institute of Photonic Sciences (ICFO) and a fellow of the Cellex Foundation Barcelona, is working on a strategy called "plasmonic oncology" that he claims will revolutionise cancer treatment.
The idea is to introduce gold nanoparticles into tumour cells, to which laser light would subsequently be applied. The nanoparticles would heat up to such a degree that the damaged cells would be completely burnt.
What is revolutionary about this use of nanoparticles is that they can be designed in such a way that they can be selectively introduced into a patient's body so that they penetrate only damaged cells. Unlike with chemotherapy and radiotherapy, the treatment would affect only tumour tissues without damaging healthy ones.
The system has resulted from nanoparticle engineering carried out by the researchers. First, the nanoparticles must be able to recognise damaged cells and, second, they must become excellent nanosources of heat. The former is achieved by coating the nanoparticles with molecules that detect and go into the cancer cells. With the latter, the nanoparticles are designed so that their shape optimises the generation of heat in response to an external light source.
The project is still at the experimental stage and is being undertaken in collaboration with experts in medicine and biology. One of the key processes in the experimental work is the selection of the particles from the damaged cells, which are inserted once their possible toxicity has been minimised. In principle, gold is biocompatible and is readily evacuated by body fluids, but the researchers must make sure that the chemistry involved in the process does not affect the cells.
The interaction between light and gold nanostructures is useful not only for the treatment of cancer but also for its diagnosis.
Quidant is working on a chip that is made up of a multitude of metal nanostructures that are able to send a light signal when they come into contact with cancer markers.
This "nanolaboratory" performs a vast number of analyses in parallel from a single drop of blood. Each metal nanostructure is coated in receptors that are able to recognise and trap a specific cancer marker. When this happens, the nanostructure responds to the external light differently from when no markers are trapped.
The researchers have already developed a nanosensor prototype that detects doping substances in the blood, such as steroids.
The main advantages of this type of device are its small size and its sensitivity, which would make it possible to detect cancer in its early stages when there is a low density of markers.
Quidant anticipates that the detector will be ready within the next ten years.