Figure 3.

Activation of infection responsive dressings. Examples of non-activated (OFF) and activated (ON) prototype infection responsive dressings originally described by Thet et al. (2015). Dressings consist of carboxyfluorescein loaded lipid vesicles embedded in an agarose matrix. At high concentrations in vesicles, carboxyfluorescein exhibits self-quenching properties that suppresses visible color. Lysis of vesicles by bacteria liberates the dye which diffuses through the dressing leading to development of a bright green color visible to the naked eye. In examples above, dressings incubated for 6 h in wound models with PBS or S. aureus RN6911 (which is deficient in the Accessory Gene Regulator agr), show no dressing activation. In contrast, dressings incubated with MRSA252 and RN6390B (parental strain of RN6911 with functional agr) show clear dressing activation.