Chronic wounds are a significant burden to patients, health care professionals, and health care systems worldwide. Diagnosis of wound infection currently relies on clinical judgment, which varies widely and is subjective in nature, as well as culture-based tests, which can take days to yield results. This can lead to inappropriate use of empiric antibiotics, which is an increasing healthcare concern due to the emergence of drug resistant microbes. Thus, there is a need for better methods of early wound diagnosis and treatment guidance. An accurate, image-based method that identifies infection within wounds would address a significant unmet need for rapid point-of-care wound care diagnostics. Early recognition of infection, identification of pathogenic microorganisms, and assessment of pathogenic load would have a major impact on delivering optimum wound management and hence healing rates.
Canadian molecular imaging Scientist Dr. Ralph S. DaCosta, and colleagues at the Princess Margaret Cancer Center and Techna Institute for the Advancement of Technology for Health, University Health Network (Toronto), have developed a novel investigational handheld autofluorescence imaging platform, named PRODIGI, which is intended to non-invasively detect and track bacterial infections in wounds. PRODIGI enables real-time, non-contact, high-resolution visualization of pathogenic bacteria through their endogenous autofluorescence, without the use of contrast agents. The imaging platform prototype includes both a handheld device and a smartphone imaging device.
PRODIGI has been validated in preclinical studies using a mouse skin wound model infected with bacteria, to determine if PRODIGI could image bacteria in skin wounds and measure the changes in the amount of bacteria over time. Dr. DaCosta and colleagues found that bacteria that cannot be seen using current standard clinical examination techniques can be visualized and “mapped” in wounds using PRODIGI. They also found that PRODIGI detected measurable changes in the amount of bacteria in and around wounds over time, following antibiotic treatment.
These preclinical studies potentiated on-going clinical trials of PRODIGI in patients with chronic wounds, mainly diabetic foot ulcers. PRODIGI is approved by Health Canada as a Class II medical device for clinical investigational testing as well as by the Canadian Standards Association. A two-part Phase I, single center, non-randomized clinical trial of PRODIGI for detecting pathogenic bacteria, guiding wound treatment, and assessing treatment response in chronic wound patients is currently underway at the University Health Network.
Dr. DaCosta describes PRODIGI as a “novel fluorescence-based imaging platform combining low-cost instrumentation and specific autofluorescence identification for in situ, real-time wound infection assessment, therapeutic guidance, and response monitoring.” According to Dr. DaCosta, “The device shows promise for image-guided wound sampling, cleaning, debridement, and quantitative monitoring of treatment response. The novelty of the method and the positive initial clinical findings should also have wider interest to clinicians and scientists beyond chronic wounds: for example infection in surgical sites, radiation skin damage and skin grafts for burn treatments. This in vivo platform can also serve as a new tool in wound care research, by providing an objective way to assess emerging wound treatments based on antimicrobial strategies.”
Dr. DaCosta has also raised funds for commercialization of PRODIGI through the creation of MolecuLight Inc., a company that is working to put PRODIGI on the map.
Study in Journal of Biomedical Optics: Autofluorescence imaging device for real-time detection and tracking of pathogenic bacteria in a mouse skin wound model: preclinical feasibility studies