Psoriasis is a chronic skin disease characterized by thickening and disorganization of the skin's protective barrier. Although current models replicate some aspects of the disease, development of therapeutic strategies have been hindered by absence of more relevant models. This study aimed to develop and characterize an in vitro psoriatic human skin equivalent (HSE) using human keratinocytes HaCat cell line grown on fibroblasts-derived matrices (FDM). The constructed HSEs were treated with cytokines (IL-1α, TNF-α, IL-6, and IL22) to allow controlled induction of psoriasis-associated features. Histological stainings showed that FDMHSE composed of a fully differentiated epidermis and fibroblast-populated dermis comparable to native skin and rat tail collagen-HSE. Hyperproliferation (CK16 and Ki67) and inflammatory markers (TNF-α and IL-6) expression were significantly enhanced in the cytokine-induced FDM- and rat tail collagen HSEs compared to non-treated HSE counterparts. The characteristics were in line with those observed in psoriasis punch biopsies. Treatment with all-trans retinoic acid (ATRA) has shown to suppress these effects, where HSE models treated with both ATRA and cytokines exhibit histological characteristics, hyperproliferation and differentiation markers expression like non-treated control HSEs. Cytokine-induced FDM-HSE, constructed entirely from human cell lines, provides an excellent opportunity for psoriasis research and testing new therapeutics.
Topical keratolytic agents such as benzoyl peroxide (BP) and salicylic acid (SA) are one of the common treatments for inflammatory skin diseases. However, the amount of drug delivery through the skin is limited due to the stratum corneum. The purposes of this study were to investigate the ability of fish oil to act as penetration enhancer for topical keratolytic agents and to determine the suitable gelator for formulating stable fish oil oleogels. 2 types of gelling agents, beeswax and sorbitan monostearate (Span 60), were used to formulate oleogels. To investigate the efficacy of fish oil oleogel permeation, commercial hydrogels of benzoyl peroxide (BP) and salicylic acid (SA) were used as control, and comparative analysis was performed using Franz diffusion cell. Stability of oleogels was determined by physical assessments at 20°C and 40°C storage. Benzoyl peroxide (BP) fish oil oleogels containing beeswax were considered as better formulations in terms of drug permeation and cumulative drug release. All the results were found to be statistically significant (p<0.05, ANOVA) and it was concluded that the beeswax-fish oil combination in oleogel can prove to be beneficial in terms of permeation across the skin and stability.