We aimed to quantify the biological effects of an innovative Pickering emulsion coencapsulating an immunosuppressive drug (e.g.cyclosporinA) in biodegradable and biocompatible PLGA nanoparticles, with an anti-inflammatory drug (e.g.calcitriol) in an oil phase, on T-cells and keratinocytes in vitro and in a murine model of psoriasis to establish the proof of concept of emulsion efficacy in vivo. T-cells were isolated from healthy volunteer' blood or skin explants and studied after CD3*CD28 activation during 6 days in vitro, for IL-2 production (ELISA), T cell proliferation (CFSE), and CD25 membrane expression (flow cytometry), while PMA+Ionomycin-mediated NFAT translocation was studied by immunofluorescence. Rhodamine-labeled PLGA nanoparticle penetration after topical application was evaluated on human skin explants by confocal microscopy. The murine model of imiquimod-induced psoriasis from van der Fits was used in vivo. Our results showed that the emulsions significantly reduced T-cell NFAT translocation and NFAT-dependent IL-2 production and proliferation. No emulsion cytotoxicity was observed on keratinocytes by MTT whereas a significant decrease in their TNFα and IL-8 production (ELISA) occurred with the emulsions as compared to controls. A significant increased rhodamine epidermal staining was observed after 24h-topical emulsion application. In vivo, a significant reduction of PASI score in psoriasis-induced imiquimod was detected after 6 days of topical emulsion application. Altogether, these results demonstrated that Pickering emulsions efficiently decrease the pro-inflammatory responses of both T cells and keratinocytes and, through epidermal penetration, contribute to efficiently reduction of psoriasis-induced lesions in vivo.

ESDR380 - Innovative Coencapsulation of Immunoactive and Anti-inflammatory Drugs for Treating Inflammatory Dermatoses

The scientific meeting of the European Society for Dermatological Research (ESDR) is held yearly, usually in September. With an international attendance of more than 1000 skin scientists from around the globe, the four-day event includes short oral presentations from peer-reviewed abstracts, keynote lectures from international experts, sponsored symposia, satellite programs, educational events as well as an important focus on posters, networking and building collaborations amongst scientists. For more information about this year’s meeting visit our website.