Figure 9.

Representative photos of H&E-stained photomicrographs for representative rat skin of (A) Group I (negative control, shaved animal skin was not swapped with S. aureus, with no samples swapping), which showed normal skin tissue; (B) Group II (positive control, animal skin was swapped only with S. aureus, and remained untreated), which showed epidermal necrosis with pleomorphic inflammatory cell infiltration and dead follicular sheets; (C) Group III (shaved animal skin was swapped with S. aureus followed by swapping with ZnO-NPs), which showed normal skin structure; (D) Group IV (shaved skin was swapped with S. aureus and then swapped with 3% PVP), which showed severe necrotic crust in epidermal area with massive pleomorphic inflammatory cell infiltration and vacuolar degeneration of skin muscles; and (E) Group V (shaved animal skin was swapped with S. aureus and then swapped with Sterillium), which showed mild inflammatory cell infiltration on the epidermal–dermal junction with limited infiltration into the dermis layer. This is indicative of the superior antibacterial activity and biosafety of ZnO-NPs compared to Sterillium.