Figure 4.

High-intensity iontophoretic delivery of vancomycin (VAN) into an ex vivo MRSA biofilm-infected porcine skin wound model using our electrical biofilm treatment system. (A) Accumulated concentration of VAN collected from skin wound tissues immediately after 1-h iontophoresis delivery at different current intensities. The drug chamber of our working device (anode) was loaded with 1 mg mL⁻¹ VAN. (B) Permeation coefficient of VAN for 1-h iontophoretic delivery at different current intensities. (C) Accumulated concentration of VAN in biofilm-infected skin wound tissues as a function of iontophoresis time. The drug chamber of the working device (anode) was loaded with 1 mg mL⁻¹ VAN and 75 mA cm⁻² was applied. (D) Accumulated concentrations of VAN collected from biofilm-infected skin wound tissues with different loading concentrations of VAN in the drug chamber of the working device after 75 mA cm⁻² current applied for 1 h. (E) Upper panel: Representative fluorescent images of cryo-sectioned skin wound samples after iontophoretic delivery of a fluorescently labeled dextran with a molecular weight of 4,000 Da (FD-4) at different current intensities for 1 h using our system (Scale bar: 200 μm). Lower panel: A three-dimensional illustration of the fluorescent intensity distribution in the skin tissue sample (in white dashed region) showed in the upper panel. Z-axis showed fluorescent intensity in random unit. X- and Y-axis had a unit of μm.