Nanoparticles may advance medical technology

Scientists at Leicester University hope to develop a new kind of nanoparticle that could improve cancer treatment and MRI scans.

Nanoparticles made by adding layers of transition metals and other materials to helium droplets could be used to create magnetic fields for use in medical technology, according to Dr Shengfu Yang of Leicester’s chemistry department.

The university recently pioneered the technique of adding atoms or molecules of a material to tiny droplets of liquid helium to create multi-layered nanoparticles.

But transition metals such as iron and cobalt, as well as metals such as sodium and potassium, remain on the surface of the droplet, limiting their use.

Yang’s new research, funded by an £800,000 ESPRC grant, will attempt to seed the helium droplets with positive ions or neutral clusters of substances such as gold or xenon, in the hope that the transition metal atoms will be dragged toward the interior.

These unique core and multi-shell magnetic nanoparticles (CMS-MNPs) will be particularly useful because of the strength of the magnetic fields they create.

They could be used to produce more focused MRI scans or to improve the effectiveness of hyperthermia cancer treatment, where microwaves heat up and destroy tumorous cells.

‘The stronger the magnetic field, the easier it would be to heat up the cells,’ Yang told The Engineer. ‘If you inject the nanoparticles into the body part with the tumour, the microwaves will interact with the magnetic field provided by the nanoparticles and the temperature will rise.’

The four-year project is primarily proof-of-principle research, but Yang said companies that have expressed an interest in the work may begin looking at possible commercial uses within two or three years.

‘We will make some really unique nanoparticles,’ he added. ‘For example, we can put something such as sodium in the core, mixing with a transition metal and then coated with a protective outer layer. I don’t think you could make these by any other means.

‘Sodium will melt at a very low temperature, 370K (97°C). But if you want to coat sodium nanoparticles with a protective material of much higher melting point – for example, 1,340K (1,067°C) for gold – the sodium core would melt or even vaporise when passing through the hot region.’