Fig. 2
Skin lesions of UVB and ZnONPs exposure. A Description of the SKH:HR-1 mouse experimental groups and exposure methods. B Hematoxylin and eosin stains of skin on SKH:HR-1 mice. Skin thickness after treatment for 72 h. The double-headed arrow indicates the thickness of the mouse epidermis. Scale bars: 200 μm. C Histograms depict the measurement of epidermal thickness following various treatments. The data is presented as the mean ± SD from three independent experiments. (**p < 0.01, ***p < 0.001 compared with control). D TEWL of the skin of SKH:HR-1 mice were detected by Tewameter after exposure for 72 h. The values are presented as percentages relative to the TEWL without treatment. a: Normal skin (control), b: 150 mJ/cm2 UVB, c: 2 mg/cm2 ZnONPs, d: 16 mg/cm2 ZnONPs, e: 150 mJ/cm2 UVB + 2 mg/cm2 ZnONPs, f: 150 mJ/cm2 UVB + 16 mg/cm2 ZnONPs, g: 150 mJ UVB /cm2 + 2 mg/cm2 post ZnONPs, and h: 150 mJ/cm2 UVB + 16 mg/cm2 post ZnONPs. E Fluorescence photomicrograph of vertical slices of OCT compound of SKH:HR-1 mouse skin after the application of R6G-labeled ZnONPs for 72 h. UVB caused skin damage, enhancing the penetration of ZnONPs into the deeper skin layer. Scale bars: 200 μm. F Multiphoton fluorescence image showing ZnONPs (green fluorescence) and collagen (blue fluorescence) in untreated skin (control), skin treated with 2 or 16 mg/cm2 ZnONPs plus 150 mJ/cm2 UVB, and skin treated with 150 mJ/cm2 UVB combined with 2 or 16 mg/cm2 post ZnONPs for 72 h. E: epidermis, D: dermis, Scale bar: 50 μm