A simple and specific colorimetric biosensor for early detection of Pseudomonas aeruginosa wound infections
Liubov Shishaeva1, Zhihao Li2, Flavia Zuber1
1Laboratory for Biointerfaces, Empa, Swiss Federal Laboratories for Materials Science and Technology, 9014, St. Gallen, Switzerland.
Insights
A new colorimetric biosensor detects Pseudomonas aeruginosa (PA) wound infections early. Using aquacyanocobinamide (ACCbi) and polyvinyl acetate (PVAc) fibers, it provides a visible color change for rapid, naked-eye monitoring.
Area of Science:
- Biomedical Engineering
- Materials Science
- Microbiology
Background:
- Wound healing complications, particularly infections from Pseudomonas aeruginosa (PA), pose significant clinical challenges.
- Early and accurate detection of PA is crucial for effective wound management and preventing severe outcomes.
Purpose of the Study:
- To develop a sensitive and specific colorimetric biosensor for the early, naked-eye detection of PA wound infections.
- To identify optimal carrier materials for the biosensor's indicator molecule.
Main Methods:
- Utilized hydrogen cyanide (HCN) as a PA-specific biomarker and aquacyanocobinamide (ACCbi) as a colorimetric indicator.
- Encapsulated ACCbi within various electrospun fibers (PVAc, PVA, PVP, PCL, PU) and evaluated their performance.
- Assessed membrane morphology via SEM, and evaluated structural integrity, sensitivity, and sensor function.
Main Results:
- Polyvinyl acetate (PVAc) based membranes exhibited superior stability and sensitivity, maintaining structural integrity and showing a distinct color change upon HCN exposure.
- The optimized PVAc biosensor demonstrated a clear color change within 10 hours for in vitro PA biofilms and 12 hours for ex vivo human skin wounds.
- The biosensor maintained functionality after two years of storage.
Conclusions:
- PVAc-based electrospun membranes are effective carriers for an ACCbi colorimetric biosensor for PA detection.
- This biosensor offers a promising, stable, and user-friendly tool for early detection and monitoring of PA wound infections in clinical settings.
Abstract:
Wound healing is a critical aspect of surgical care, often complicated by infections such as those caused by Pseudomonas aeruginosa (PA). In this study, we aim to develop a sensitive and specific colorimetric biosensor which allows early detection and naked-eye monitoring of PA wound infections. We used hydrogen cyanide (HCN) as a PA specific biomarker and aquacyanocobinamide (ACCbi), a vitamin B12 derivative, as the indicator which changes color from orange to violet upon interaction with HCN. We then encapsulated ACCbi with different electrospun fibers, including polyvinyl acetate (PVAc), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polycaprolactone (PCL), and polyurethane (PU), and evaluated them for suitability as ACCbi carriers. The morphology of the fabricated membranes was analyzed using scanning electron microscopy (SEM). The performance of the materials was assessed for their structural integrity, sensitivity and sensor function. PVAc based membranes demonstrated the best stability and sensitivity, maintaining structural integrity and showing a distinct color change in response to HCN. In a real-world setup of negative pressure wound therapy, the optimized PVAc membranes exhibited a clear color change within 10 h of exposure to PA biofilms formed in vitro and within 12 h to that on ex vivo human skin wounds. The biosensor retained its functionality after two years of storage, offering a promising tool for the early PA detection in clinical wound care.
