LEICESTER, UK: Research to be carried out at the University of Leicester will develop silver nanoparticles, in a form which can play a significant role to play in combating MRSA, Cystic Fibrosis and AIDS, as well as the treatment of wounds.

It has been known for some time that silver is highly toxic to a wide range of bacteria, and silver-based compounds have been used extensively in bactericidal applications. This property of silver has caused great interest especially as new resistant strains of bacteria have become a serious problem in public health.

For example MRSA bacteria kill 5,000 hospital patients a year in the UK alone and any method of attacking them, not involving normal antibiotics, is becoming increasingly important.

Silver in the form of nanoparticles is even more effective, partly because of the high surface/volume fraction so that a large proportion of silver atoms are in direct contact with their environment. In addition, nanoparticles are sufficiently small to pass through outer cell membranes and enter cells' inner mechanisms.

A recent medical study showed that only silver nanoparticles with sizes less than 10 nm (1,000 times smaller than the width of a human hair) were able to enter cells and disrupt them. The same study showed that silver nanoparticles are highly toxic to the bacteria that colonise the lungs of cystic fibrosis sufferers often with fatal consequences.

Another study indicated that there may be a role for nanoparticles in the fight against AIDS by showing that silver nanoparticles of the same size attach themselves to structures on the surface of the HIV virus and prevent it from binding to host cells.

Professor of Nanoscience at the University of Leicester, Chris Binns, commented: "Clearly there are important medical treatments using silver nanoparticles and this is just one of the examples of how nanotechnology shows great promise in healthcare.

"One of the problems, however, is in getting assemblies of nanoparticles of the same size into the right environment, for example on the surface of a wound dressing or in a colloidal suspension that can either be turned into an aerosol or injected into the body.

"The medical studies carried out so far acknowledge that in existing commercially available nanoparticle suspensions, only 1% of the material consists of nanoparticles of the right size. The Condensed Matter Physics group in Leicester has many years' experience in designing and building sources of size-selected metal nanoparticles.

"With support from the "Higher Education Reach -Out to Business and the Community Innovation and Regional Fund" (HIRF) this is now being put to good use to develop a machine specifically to produce nanoparticle assemblies for medical applications. The impressive uniformity of silver nanoparticles produced by the source is illustrated in the figure (available on request) and the design enables the nanoparticles to either be coated onto a solid surface or incorporated into a liquid suspension."

Trials of the anti-microbial effectiveness of the nanoparticle suspensions will begin shortly.

Ather Mirza
Director of Press and Publications
University of Leicester
University Road
Leicester
LE1 7RH
tel: 0116 252 3335
email: pressoffice@le.ac.uk

THE UNIVERSITY OF LEICESTER

The University of Leicester is the UK's top ranked University for teaching quality and overall satisfaction amongst universities teaching full time students and was rated joint 1st in the UK in the 2005 National Student Survey. Founded in 1921, the University of Leicester has 19,000 students from 120 countries. Teaching in 18 subject areas has been graded Excellent by the Quality Assurance Agency- including 14 successive scores - a consistent run of success matched by just one other UK University.

Leicester is world renowned for the invention of DNA Fingerprinting by Professor Sir Alec Jeffreys and houses Europe's biggest academic Space Research Centre. 90% of staff are actively engaged in high quality research and 13 subject areas have been awarded the highest rating of 5* and 5 for research quality, demonstrating excellence at an international level. The University's research grant income places it among the top 20 UK research universities.

The University employs over 3,000 people, has a turnover of £300m, covers an estate of 94 hectares and is engaged in a £300m investment programme- among the biggest of any UK university.