Outbreaks of clinical infections affect many thousands of patients in Europe yearly. The present effective treatment for infections is large doses of systemically applied drugs. There is a high risk of recurring infections and biofilm formation for patients dependent on long term in-dwelling catheters and the extended dependency on antibiotics resulting in clinical drug resistance. We present a new tool for minimizing drug resistance by upgrading existing and future medical devices through a unique self-regenerating surface that prevents biofilm formation using a stealth attack mechanism. This will be achieved by an interpenetrating polymer network (IPN) that allows for long term release of a range of antimicrobial strategies. The IPNs contain hydrogels where the antimicrobial is stored until the release starts at the insertion of the device with an expected long-term effect. Local and site-specific treatment with long term effect instead of systemic treatment implies improved patient management and citizen well-fare.
A schematic of IPN silicon hydrogel as a reservoir for antibacterial drugs for use in urinary catheters.
The increased prevalence of antibiotic resistant bacteria poses a serious threat to the health of European citizens, with cases of hospital acquired urinary tract infections (UTI’s) in the five largest Europe nations exceeding a total of 1.5 million cases per year.
Hospital and care acquired infections (HAI) are now the fourth largest cause of death in the western world. The ECDC estimates that within Europe around 4.1 million patients (equivalent to 1 in 20 hospitalized patients) acquire infections whilst hospitalised. In 2008, as consequence of non-fatal HAI, patients spent an extra 2.536 million days in hospital. Collectively the direct and indirect costs of HAIs for the EU are estimated to be EUR 1.534 billion per annum. One of the most common HAI worldwide is caused by urinary catheters. The risk of infection increases with every additional day of catheter usage resulting in a high risk of infection within a few days after insertion requiring the use of systemically applied drugs.
For decades antibacterial coatings have failed to prevent pathogenic bacteria from spreading and forming biofilms. The main reason for this is that coatings are fragile and in most cases rapidly lose effect. The only option seems to be development of self-regenerating coatings which can function in a controlled way for a long time on polymer devices. BacAttack will combine novel hybrid materials, noble metals and advances within Anti Microbial Peptides (AMPs) and integrate them into a material with a self-regenerative surface. By focusing on both material and drug the tools developed for preventing biofilms will gain a generic methodology. The goal of the project is to build a hybrid material that will be used for preventing microbial infections associated with medical devices.
BacAttack will generate a paradigm shift by use of silicone rubber as a platform for hydrogel impregnations with ground-breaking drug delivery capabilities and contribute to significantly reducing the instances and associated costs of HAIs, in particular those associated with catheters.
In the first instance catheters will be used as a test bed for the new technology. However, the ultimate aim of the project partners is to widen the scope and include other medical devices, such as stents, wound dressings and contact lenses.