Wound infections of either accidental wounds or surgical sites arise when microorganisms from the surrounding environment are able to colonise in the wound of a susceptible host. As clinical identification of wound infections can often take time the infection becomes deeper causing conditions such as sepsis & abscess formation. This in turn leads to increased length of hospitalization & hospital costs. Wound infections are a principal mode of hospital-acquired infections (HAI) & remain a significant cause of patient morbidity and mortality. Currently they are treated with systemic antibiotic drugs. However as most pathogenic bacteria are able to form a biofilm, established infections are harder to treat, as bacteria in a biofilm are up to a reported 500 times more resistant to antibiotics. Furthermore the use of broad spectrum &/or prolonged use of antibiotics can predispose patients to colonisation of resistant organisms, eg. MRSA & may contribute to the increasing emergence of antibiotic resistance. Recently the European Wound Management Association has suggested that there is an urgent need to develop antimicrobial treatment regimes that do not include antibiotic drugs. This research aims to detect and treat bacterial wound infections by designing a novel smart wound dressing which releases bacteriophage (bacteria killing viruses) into the wound in response to a trigger event or stimuli, thus giving a burst release of bacteriophage only when required. The research will be split into two parts i) the development & optimisation of bacteriophage cocktails ii) the development of the smart dressing, focusing on treating S. aureus infections, as they are the most commonly isolated pathogen in wounds. Bacteriophage optimisation will involve obtaining & characterising bacteriophages for this study including discovering the bacteriophages spectrum of activity & structure. Next the virulence & spectrum of activity of the chosen bacteriophages will be enhanced using a breeding programme; DNA/RNA characterisation will be undertaken to determine if there are any significant changes & if any genes encoding resistance or virulence factors are present. Finally the phage cocktails will be tested using planktonic bacteria, biofilm models & testing on pigskin. Once the correct phage cocktail has been ascertained it will be incorporated into a wound dressing. Utilising lysin residues it is possible to covalently bind bacteriophage to poly(acrylic acid) PAA hydrogels in the presence of biotin & streptavidin via the formation of ester linkages. Staphylococcus aureus produce esterases as a virulence factor & hence are able to hydrolyse the ester linkage in the PAA hydrogels, releasing the bacteriophage in a burst response, killing the bacteria in the surrounding environment. This project has many benefits over current treatments. The triggered release system utilises bacterial virulence factors produced by the pathogen at the wound site releasing the bacteriophage only in the presence of S. aureus, thereby eliminating non-specific drug release. This could potentially slow down the emergence of resistant bacterial strains. In addition to this using bacteriophage as the antibacterial agent is a viable alternative to antibiotics as they are abundant in nature, easy to isolate, host strain specific, harmless to eukaryotic cells & have had no reports of emerging resistant bacteria. Furthermore this method for detection & treatment of wound infections should be quicker than current treatments, allowing for infections to be treated earlier, reducing the emergence of further issues including sepsis. The main aim of MRC GW4 BioMed DTP Infection, Immunity & Repair theme is to improve human health & focuses on reducing the antimicrobial resistance crisis by looking at viable alternative methods to treat bacterial infections. It is strongly multi-disciplinary, needing both chemistry & microbiology skills to be successful.