Antimicrobial Biomaterials - Application to Medical Devices aimed at the minimisation of implant associated infection


Antimicrobial Catheters


Dr Roger Bayston of the University of Nottingham has developed an antimicrobial impregnation process which prevents indwelling catheters and related medical devices from becoming contaminated with microbes.




Published figures suggest that upwards of 10% of patients with indwelling catheters develop infections as a direct result of having a catheter in place.

Catheters incorporating our new technology promise to dramatically reduce such infections. Related technology, previously developed by Dr Bayston, and already in commercial use has resulted in a fall in infection rate from 10% to much less than 1%.

The newly developed technology is based on a combination of antimicrobial compounds tailored to give protection against both Gram positive and Gram negative bacteria. Our new antimicrobial catheters and related devices have the potential to be used in all areas of the body and will protect against common infectious agents including MRSA, Staphylococcus epidermidis, E.coli and Proteus.


Key Benefits


  • Patients who develop infections as a result of indwelling catheterisation suffer discomfort, a further reduction in health and the requirement to both treat the infection and replace the catheter. All of these problems can be solved by the use of our new impregnation technology which make use of very low, but highly effective, levels of tailored antimicrobial compounds active at the point of need.
  • Protection lasting over 200 days against infections by both Gram positive and Gram negative bacteria has already been rigorously demonstrated in simulated in vivo assays. Neither colonisation nor the appearance of resistant strains have been observed.

Technical Information


The technology relies on the ability of silicone material to swell in the presence of a solvent such as chloroform. A number of antimicrobials, including antibiotics and synthetic small molecules with activity against bacteria, can be made to dissolve in solvents such as chloroform. When silicone medical devices such as catheter tubes are suspended in chloroform containing dissolved antimicrobials, the tubing swells under the influence of the solvent and antimicrobials are carried into the matrix of the silicone device by the chloroform. After a set period of time the tubing is removed from the solvent and air-dried. This removes the solvent, but leaves the antimicrobial molecules dispersed throughout the catheter matrix. Autoclaving sterilises the tubing and drives off any residual solvent.

The catheter matrix acts as a source of antimicrobials which are slowly dissipated (over 6-8 months). Once in situ in the body, the antimicrobials slowly migrate to the inner lumen surface and the outer surface of the catheter maintaining a Nernst diffusion layer which prevents bacterial colonisation of any biofilm on the surface of the catheter. This approach minimises the amounts of antimicrobials needed to prevent colonization and development of resistance and also ensures that they are delivered only to the site where they are needed.


IP Status


The University of Nottingham has filed a patent application for this technology (publication number WO 2006/032904) and is looking to expand the number of licences already granted to this technology.

Patent Information:
Medical Device
For Information, Contact:
Gillian Shuttleworth
IP Commercialisation Manager
The University of Nottingham
0115 82 30042
Roger Bayston
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