Polymers could help prevent device-associated infections

The polymers, when applied to the surface of medical devices such as catheters, repel bacteria and prevent them forming biofilms, which have the potential to cause medical-device-associated infections.

According to a statement, such infections can lead to systemic infections or device failure, costing the NHS £1bn a year.

The research at Nottingham was led by Prof Morgan Alexander, along with Prof Martyn Davies in the School of Pharmacy and Prof Paul Williams in the School of Molecular Medical Sciences.

The results of the £1.3m four-year research project, supported by a Translation Award from the Wellcome Trust, were published on 12 August 2012 in Nature Biotechnology.

Researchers believed there were new materials that could better resist bacteria, which meant screening thousands of different chemistries and testing their reaction to bacteria — a challenge that was beyond conventional materials development or current understanding of the interaction of micro-organisms with surfaces.

The discovery has been made with the help of experts from the Massachusetts Institute of Technology (MIT) — who initially developed the process by which thousands of unique polymers can now be screened simultaneously.

Alexander said: ‘This is a major scientific breakthrough — we have discovered a new group of structurally related materials that dramatically reduce the attachment of pathogenic bacteria [Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli].

‘We could not have found these materials using the current understanding of bacteria-surface interactions. The technology developed with the help of MIT means that hundreds of materials could be screened simultaneously to reveal new structure-property relationships.

‘In total, thousands of materials were investigated using this high-throughput materials discovery approach, leading to the identification of novel materials resisting bacterial attachment. This could not have been achieved using conventional techniques.’

These new materials are said to prevent infection by stopping biofilm formation when the bacteria first attempt to attach themselves to the device.

In the laboratory, experts were able to reduce the numbers of bacteria by up to 96.7 per cent — compared with a commercially available silver containing catheter — and were effective at resisting bacterial attachment in a mouse implant infection model.

By preventing bacterial attachment, the body’s own immune system can kill the bacteria before they have time to generate biofilms.

Ted Bianco, director of technology transfer at the Wellcome Trust, said: ‘Infections caused by microbial biofilms binding to the surface of implants often cannot be treated with conventional antibiotics.

‘This makes them a significant challenge in patient care, particularly for those with inserted medical devices such as catheters, heart valves and prosthetic joints.

‘The discovery of these new polymers is a great example of how advances in materials science are being exploited in our efforts to improve the performance of critical medical components.’

The next stage of this research will be to develop the manufacture of these coatings to enable the performance of these materials to be assessed clinically, and the inventors are in early-stage discussions with a number of medical-device companies.