Background: Burn is one of the factors in the spread of disease. To treat burns, several topical medications are required. This study was performed to evaluate the effects of topical nano zinc oxide on skin burns of adult female mice of NMRI.

Materials and methods: 30 adult female mice of the NMRI were placed in groups of control1(without burns), control2 (burns without healing), sham (burns distilled water tween 20), experimental 1 (burns and distilled zinc oxide 300mg), and experimental 2 (burns and distilled zinc oxide 500mg). In sterile conditions and anesthesia, a wound was created with diameter of one centimeter on the back of each mouse. The mice were treated for 21 days and were easy to draw. The thickness of the horny layer, epidermis, dermis, hypodermis, number of hair follicles and number of dermic vessels and vessel diameter, the diameter of the wound and scar was evaluated.

Results: Diameter of scar in all groups revealed reduction (P<0.001) compared to control 2. Thickness of horny epiderm significantly increased (p <0.001) in groups of control 1, sham, experimental 1, and 2 compared to control 2. The thickness of the hypoderm increased in groups of sham (p<0.01), control 1, experimental 1, and 2 (P<0.001) compared to control 2. Thickness of the dermis was larger in groups of control 1, sham, experimental 1 , and 2 (P <0.001) in comparison of control 2 group. The number of hair follicles was decreased in control 1 group (P<0.01) and increased in groups of sham (p<0.01), and experimental 1 and 2 (P <0.001) compared to control 2. There were no significant differences in the number of dermic vessels and the diameter of dermic vessels between groups.

Conclusion: Results showed that nano zinc oxide had good effects on burned skin layers and hair follicles.

Keywords: Nano-zinc oxide, Skin burn, Healing, Dermis, Epidermis.