CASE STUDY: UNIVERSITY OF LIMERICK:THE DEVELOPMENT of clothing that kills superbugs may seem like the stuff of science fiction, but it is fast becoming a reality thanks to the work of a team co-ordinated by the Materials and Surface Science Institute at the University of Limerick.
The BioElectricSurface research team has succeeded in bonding certain nanoparticles onto textiles used in hospital uniforms, drapes, bed linens and upholstery, transforming them into powerful anti-bacterial materials in the process. Nanoparticles are 1,000 times smaller than the width of a human hair and possess extraordinary properties, which the team has harnessed to fight MRSA, the antibiotic-resistant superbug.
The MRSA bug is one of the major causes of hospital-acquired infections. The European Centre for Disease Prevention has identified such micro-organisms as the most important infectious disease threat in Europe. One in 10 patients entering a European hospital can expect to catch an infection caused by drug-resistant microbes. Every year, about 3 million people in the European Union catch a healthcare-associated infection, resulting in about 50,000 deaths.
“As they get smaller, certain nanomaterials become photoactive,” explains Dr Syed Tofail, the project coordinator. “These photo-catalytic properties mean that when the particles are exposed to light, they produce an electrical charge that can crack water molecules. This produces hydrogen peroxide and ozone, which are both anti-bacterial substances.
“These properties were already well known and are already used in the manufacture of self-cleaning glass. What we have done is to build them into a textile to make it anti-bacterial.”
The BioElectricSurface research team comprises scientists and engineers from the University of Limerick, Comenius University in Slovakia, Wroclaw University of Technology and Wroclaw Medical University in Poland, who have been working on developing this technology since 2008.
They have embedded commercially available and custom-made nanoparticles into textiles through a patent-pending process. The process ensures the nanoparticles adhere tightly to the textile, which is an essential feature as it minimises “free” or “loose” particles.
Among the difficulties faced by the team was the very different nature of the particles to be bonded and the textiles. “We are trying to bond hard and soft materials together while retaining the characteristics of both,” Tofail explains. “We have developed a method of applying the nanoparticles to the surface of the textile in such a way that their anti-bacterial properties are enhanced.”
The trick here lies in the application of the particles in a non-uniform pattern. It is not simply a question of painting a layer of nanoparticles onto a textile, more a case of sprinkling them in such a way that the surface area exposed to light is maximised. This enhances their photo-activity and effectiveness against MRSA and other bugs.
The bonding process is also critical as the textile has to be able to withstand normal wear and tear and laundering without the particles being worn or washed away. “We are at the very preliminary stages of our investigations but we have shown that the textile can be washed up to 10 times without losing its anti-bacterial properties,” says Tofail.
“We are trying to improve this to the industrial standard of 50 to 100 washes. This is particularly important for items such as nurses’ uniforms, which have to be washed very frequently.”
The benefits of this new technology are immense as it solves an existing problem as well as directly fighting MRSA.
Dr Ewa Dworniczek, a microbiologist from the Wroclaw Medical University and a member of the BioElectricSurface team, says: “Most textiles used in non-surgical environments are conventional, which partly gives rise to the spread of infectious diseases even among patients who go to hospital for non-surgical care.
“These garments can pose a public health risk due to the inability of current hospital laundries to annihilate bacteria that have grown antibiotic resistant in the hospital environment.”
The commercial potential is huge. The US and European market for medical textiles is estimated to be worth more than $7 billion (€4.8 billion). In addition, the World Health Statistics for 2007 show there were 7.94 million nurses registered in Europe and the US then. Assuming the average cost of a standard reusable uniform is $40, the team estimates a total annual value of $634 million for this segment alone. “Our technology will be used to produce practical, economical and effective products for this huge potential market,” says Tofail.
“This is such a broad technology it has numerous applications across a number of areas. In healthcare, it could be used against specific strains of bacteria. We already know it works fantastically well against MRSA. We will also look at it in terms of different textiles. You could spend your whole life adapting the technology to different textiles.
“The properties are amazing: if you go outside on a sunny day wearing clothes made of textiles containing these nanoparticles your clothes will get cleaner as you walk around. Our target is to have the technology available commercially with the next two or three years.”