Lipase-Responsive Electrospun Theranostic Wound Dressing for Simultaneous Recognition and Treatment of Wound Infection.

Simultaneous monitoring and treatment of wound infection is of great importance in the biomedical field. The present work describes the development of a theranostic wound dressing (TH-WD) that can monitor and inhibit wound infection simultaneously. The main component of TH-WD is a polyurethane (PU) scaffold loaded with a ciprofloxacin-based prodrug (Pro-Cip) and a chromogenic probe (H-Cy).  In vitro studies demonstrated that TH-WD displayed efficient inactivation (100 ± 4% reduction) of  Pseudomonas aeruginosa (ATCC 27853) within 4 h of contact while providing a visual detection of wound infection via a simple color change from yellow to green to red. These results are attributed to the activation of H-Cy and Pro-Cip via hydrolysis of their ester linkages catalyzed by lipase, an extracellular enzyme secreted by bacteria. Moreover, TH-WD is highly selective as it only changes color and releases the active drug (ciprofloxacin) in the presence of certain lipase-secreting pathogenic bacteria such as P. aeruginosa ATCC 27853, and no color change and cytotoxicity were observed when TH-WD was incubated with no- or low-lipase-producing bacteria (e.g., E. coli TOP 10) or skin cell fibroblast. This hence can minimize the emergence of bacterial resistance associated with the overuse of antibiotics and avoid unnecessary cytotoxicity to skin cells. The present system not only provides a visible and noninvasive method to monitor the wound status but also allows the timely administration of antibacterial agents to inactivate bacteria in the wound.