Coencapsulation of Immunosuppressive Drug with Anti-Inflammatory Molecule in Pickering Emulsions as an Innovative Therapeutic Approach for Inflammatory Dermatoses.

Psoriasis is an inflammatory skin disease characterized by epidermal and immune dysfunctions. Although efficient, current topical treatments display adverse effects, including skin atrophy and burning sensation, leading to poor patient adherence. To overcome these downsides, pickering emulsions were formulated in which the calcitriol-containing dispersed phase was stabilized with either cyclosporin A- or tacrolimus-loaded poly(lactic-co-glycolic) acid nanoparticles. This study aimed to investigate their biological effects on lymphocytes and epidermal cells and their effectiveness in an imiquimod-induced psoriasis-like mouse model. Results showed that both emulsions significantly inhibited nuclear factor of activated T cell translocation in T lymphocytes as well as their IL-2 production, cell activation, and proliferation. In keratinocytes, inhibition of nuclear factor of activated T cell translocation decreased the production of IL-8 and TNF-α. Topical application of emulsions over skin biopsies ex vivo showed accumulation of rhodamin B-coupled poly(lactic-co-glycolic) acid nanoparticles throughout the epidermis by immunofluorescence and significantly decreased the antigen-presenting capacity of Langerhans cells in relation to a reduced expression of activation markers CD40, CD86, and HLA-DR. Using an imiquimod-induced psoriasis model in vivo, pickering emulsions significantly alleviated psoriasiform lesions potentially attributed to the decreased cutaneous expression of T-cell markers, proinflammatory cytokines, chemokines, and specific epidermal cell genes. Altogether, pickering emulsion might be a very efficient formulation for treating inflammatory dermatoses.

In vitro effects of wound-dressings on key wound healing properties of dermal fibroblasts.

Healing of complex wounds requires dressings that must, at least, not hinder and should ideally promote the activity of key healing cells, in particular fibroblasts. This in vitro study assessed the effects of three wound-dressings (a pure Ca2+ alginate: Algostéril®, a Ca2+ alginate + carboxymethylcellulose: Biatain alginate® and a polyacrylate impregnated with lipido-colloid matrix: UrgoClean®) on dermal fibroblast activity. The results showed the pure calcium alginate to be non-cytotoxic, whereas the other wound-dressings showed moderate to strong cytotoxicity. The two alginates stimulated fibroblast migration and proliferation, whereas the polyacrylate altered migration and had no effect on proliferation. The pure Ca2+ alginate significantly increased the TGF-ß-induced fibroblast activation, which is essential to healing. This activation was confirmed by a significant increase in Vascular endothelial growth factor (VEGF) secretion and a higher collagen production. The other dressings reduced these fibroblast activities. The pure Ca2+ alginate was also able to counteract the inhibitory effect of NK cell supernatants on fibroblast migration. These in vitro results demonstrate that tested wound-dressings are not equivalent for fibroblast activation. Only Algostéril was found to promote all the fibroblast activities tested, which could contribute to its healing efficacy demonstrated in the clinic.