Figure 4.

Smart and automated bandages for treatment of chronic wounds. (a) Schematic and a representative image of multi-layer dressing, which was capable of sensing the wound pH and releasing antibiotics in response to the activation of an integrated heater. The sensing data was processed on board and the heater could be activated in response to the changes in the environmental condition. (b) Cyclic activation of the heater and the variation in drug release in response. (c) Schematics of an in vitro model utilized for culturing of Staphylococus aurous in a bioreactor interfaced with the bandage. (d) The bandage was continuously monitoring the bioreactor pH and once a critical pH was detected, antibiotics were released. The eradication of bacteria followed by continuous perfusion led to recovery of the bioreactor pH. (e) Schematic of a semi-automated bandage with colorimetric pH sensor and drug delivery capability. (f) The bacterial growth could affect the color of the engineered bandage, as shown by the darkening color in (I)-(IV) as CFU increases. Figures are reproduced with permission from [74], [75].\