Fig. 4.

In vitro characterization of antibiotic release profiles and bacterial inhibition upon heat treatment. (A) Schematic of the device integrated with antibiotics-doped silk film for wirelessly activated drug release. Ampicillin molecules loaded in silk films are illustrated as orange dots embedded in a green matrix. Antibiotic release from silk fibroin films was enhanced by increasing the temperature of the device with a wirelessly activated heater. (B) The cumulative drug release profiles (after application of thermal treatment at 50 °C for 10 min) were recorded. The release profile can be adjusted by controlling the boiling time (i.e., 15, 30, and 60 min, respectively) of raw silk fibers and water annealing time (i.e., 3, 6, and 12 h, respectively) of cast silk films for preferred crystallinity level. (C and D) Thermally triggered ampicillin release profiles were evaluated by adding the different ampicillin containing solutions into growth media containing S. aureus and Escherichia coli and subsequently measuring the optical density of grown bacterial cultures after 18 h of incubation at 37 ^οC.