Skin-Permeable Nano-Lithocholic Lipidoid Efficiently Alleviates Psoriasis-like Chronic Skin Inflammations

Long-term application of topical therapeutics for psoriasis has a plethora of side effects. Additionally, skin-permeating agents used in their formulations for deeper dermal delivery damage the skin. To address these limitations, we developed novel lithocholic acid analogues that could form lipid nanoparticles (nano-LCs) spontaneously in the aqueous milieu, permeate through the skin, penetrate the deeper dermal layers, and exert anti-inflammatory effects against psoriasis-like chronic skin inflammations. Prior findings demonstrated that lithocholic acid acts as a vitamin D receptor agonist without affecting the CA⁺² metabolism and also as an antagonist for ephrin type-A receptor 2 (EphA2). Taking cues from the previous findings, lithocholic acid derivatives with twin alkyl chains (LC6, LC8, LC10, and LC-12) were synthesized, nanoparticles (nano-LCs) were prepared, and they were evaluated for their skin permeability and anti-inflammatory properties. Among these nano-LCs, nano-LC10 demonstrated superior anti-inflammatory properties and inhibition of keratinocyte proliferation in various cell-based evaluations. Furthermore, the therapeutic efficiency of nano-LC10 was evaluated in an imiquimod-induced psoriasis-like mouse model and demonstrated comparable efficiency with the standard topical formulation, Sorvate, in reducing skin inflammations. Nano-LC10 also reduced systemic inflammation, organ toxicity, and also proinflammatory serum cytokine levels. Overall, nano-lithocholic lipidoid (nano-LC10) can be a potential novel class of therapeutics for topical application in treating psoriasis.