Fluorescing Polymers Detect and Assess Wound Infection

Polymers that fluoresce in the presence of bacteria enable rapid detection and assessment of wound infection using ultra-violet light. This technology should ultimately reduce the detection of bacterial infection to within a few hours, or even less.

Clinicians will be able to determine the severity of infection by the level of fluorescence when the polymers are contained in a gel and applied to a wound.

The polymers are irreversibly attached to fragments of antibiotics, which bind to either Gram negative or Gram positive bacteria–both of which cause very serious infections–informing clinicians as whether to use antibiotics or not, and the most appropriate type of antibiotic treatment to prescribe.

The polymer (PNIPAM), modified with an antibiotic (vancomycin) and containing a fluorescent dye (ethidium bromide), shows a clear fluorescent signal when it encounters Gram-negative bacteria. Other polymers have been shown to respond to Staphylococcus aureus, Gram-positive bacteria. These advances mean that a hand-held sensor device can now be developed for use in a clinical setting.

Currently, determining significant levels of bacterial infection involves swabbing the wound and culturing the swabs in a specialist bacteriology laboratory with results taking several days to be available. The University of Sheffield (United Kingdom) team also found that they could use the same gels to remove the bacteria from infected wounds in tissue engineered human skin.

Prof. Sheila MacNeil, an expert in tissue engineering and wound healing, explained: "The polymers incorporate a fluorescent dye and are engineered to recognize and attach to bacteria, collapsing around them as they do so. This change in polymer shape generates a fluorescent signal that we´ve been able to detect using a hand-held UV lamp."

"The availability of these gels would help clinicians and wound care nurses to make rapid, informed decisions about wound management, and help reduce the overuse of antibiotics," added project lead Dr. Steve Rimmer.

Related Links:
The University of Sheffield