Multifunctional chitosan-coated poly(lactic-co-glycolic acid) nanoparticles for spatiotemporally controlled codelivery of ceramide and C-phycocyanin to treat atopic dermatitis

Atopic dermatitis is an inflammatory disease associated with defective skin barrier. The co-administration of a lipid-enhancing skin barrier composed of ceramide with an anti-inflammatory agent is required to effectively treat atopic dermatitis. As atopic dermatitis treatment is affected by the dosage and frequency of medication, the development of nanoparticles that have long-term efficacy with a single dose would be advantageous. In this study, skin-sensitive chitosan nanoparticles codelivering ceramide and C-phycocyanin were developed to provide anti-inflammatory effects with no cytotoxicity, and their effect on stratum corneum formation in a rat atopic dermatitis model was examined. Analysis of the messenger RNA expression of keratinization factors demonstrated that the stratum corneum–formation effect of poly(lactic-co-glycolic acid) nanoparticles containing ceramide was similar to or higher than that of ceramide alone. Compared to the nanoparticles without C-phycocyanin, nanoparticles coated with C-phycocyanin and chitosan attenuated histamine release. In addition, despite frequent washing, the nanoparticles were well fixed to the epidermis after their administration. The results suggest that a single treatment with the combination of lipid therapy/anti-inflammatory nanoparticles is a convenient and high-efficiency means to increase stratum corneum formation in atopic dermatitis patients.