Background/Purpose: Particularly in pediatric patients, determining the cause of symptoms that arise with an infected wound can be tricky. I saw a gap in the biotechnology marketplace for a simple wound dressing that alerts patients when to seek medical attention for a possibly infected wound. In infected wounds, bacterial growth causes the breakdown of the extracellular matrix (ECM), producing basic byproducts. This rise in pH is reflected in the exudates produced by an infected wound and occurs immediately after contamination. Generally, the pH increase continues to rise until reaching a plateau, often after a few days of uncontrolled bacterial growth. Since clinical symptoms typically onset after 24 hours, using pH as a metric to determine if a wound could be infected would facilitate exceptionally faster diagnoses of wound infections. My goal was to develop a wound dressing that, using pH, would allow patients to be able to make more informed decisions about seeking medical attention for possibly infected wounds and facilitate significantly quicker detection of infected wounds, which would lead to faster healing. Methods: Begin by inoculating 6 tubes of 8 mL of LB broth, each with a one (1) colony of S. Epidermidis. Incubate the cultures for five (5) days. Every 24 hours from initial inoculation, remove the cultures from the incubator and use a digital pH probe to test the pH. Use this data to determine the optimal range for a binary detection tool. Then, using a variety of different band-aids and pH paper meters, construct distinct band-aids. Inoculate a fresh colony of S. Epidermidis in LB broth and after twelve (12) hours, micropipette 100 μL of LB broth onto each band-aid. Use a visual metric to determine which construction provides the clearest binary visual guide to inform users whether to seek medical attention for their wound. Results: The optimal range to decipher between infected and non-infected wounds is 5.9 to 6.1 as this pH range occurs consistently within the first 24 hours while having a substantial buffer from the normal range (5.0 to 5.5). The Band-Aid brand clear water block with Hydrion 5.5-8.0 pH paper embedded into the gauze provides the most distinct binary guide to users. Conclusion: Given that the pH of an infected wound invariably increases, pH is a reliable metric to inform users of the healing status of their wound. In testing the chronological pH increase of a culture of S. Epidermidis, I was able to determine the optimal range for a detection tool (5.9-6.1) and the best band-aid and pH test paper for this purpose (Band-Aid water block clear and Hydrion 5.5-8.0 paper). In the future, I plan on testing the accuracy and efficacy of this band-aid with patients in a clinical setting.
Band-Aid: Sterile vs. S. Epidermidis contaminated broth
Band-Aid Clear Water Block shown with 100 μL of sterile LB broth (left) and 100 μL of LB broth contaminated with S. Epidermidis (right)
pH changes in six (6) cultures of S. Epidermidis grown in LB broth