Topical Application of Nano-sized Graphene Oxide Cream Ameliorates Acute Skin Inflammation in Mice

We have previously shown that nano-sized graphene oxide (NGO) displays anti-inflammatory activities against natural killer T (NKT) cell-mediated sepsis. To address whether NGO could be applied to treat acute skin inflammation we developed a conventional skin Cetaphil® cream containing NGO (NGO cream) for topical application to skin lesions and investigated its therapeutic efficacy by employing the tape-stripping-induced acute skin inflammation model. Topical application of NGO cream to the wounded area significantly reduced skin lesions compared with the control cream. Moreover, NGO cream treatment prevented the tape-stripping-elicited infiltration of and IL1β production by skin neutrophils and dendritic cells (DCs). Furthermore, such anti-inflammatory effects of NGO cream were attributed to decreased infiltration of IL12-producing DCs and IFNγ-producing cells (e.g., CD4+ T, CD8+ T, γδ T, NK, and NKT cells) into the skin. In addition, topical NGO cream administration enhanced the expression of suppressive molecules such as FR4 on skin regulatory T cells. Through RNA sequencing analysis, we found that the preventive effect of NGO cream on acute skin inflammation may be correlated with the activation of keratinocytes located in the epidermis. Our results support NGO cream as a therapeutic option to control acute skin inflammation.