Feasibility of combining JAK1 gene editing via CRISPR-CasRx with EGCG–lactoferrin nanoparticle therapy in a microneedle-based platform for atopic dermatitis

Atopic dermatitis (AD) is an inflammatory skin disease characterized by a complex pathogenesis. Current clinical treatments exhibit several limitations, including low efficacy and considerable side effects, prompting a growing interest in novel therapeutic strategies. In this study, we developed a microneedle-assisted dual-nano drug delivery strategy that targets both oxidative stress and Janus kinase 1 (JAK1) expression, aiming for enhanced therapy of AD. Self-assembling nanoparticles (NPs) incorporating epigallocatechin gallate (EGCG) and lactoferrin were developed to effectively modulate oxidative stress. Concurrently, CRISPR-CasRx technology was employed to silence JAK1, and nanoparticles were constructed by encapsulating CasRx and siRNA within poly (β-amino ester) (PBAE). Both types of NPs were successfully delivered to skin lesions in AD mice through microneedles, either individually or combined, resulting in significant alleviation of symptoms. Treatment reduced dermatitis severity scores and splenomegaly, decreased epidermal thickness and mast cell infiltration, and increased collagen fiber content. Additionally, levels of inflammatory cytokines (IL-1β, IL-4, IL-13) and oxidative DNA damage marker (8-OHdG) in dorsal skin tissues were lowered, accompanied by decreased serum levels of thymic stromal lymphopoietin (TSLP) and IgE. The therapy also suppressed JAK1 expression and activated the Nuclear factor erythroid 2-related factor 2 (Nrf2)/Heme oxygenase 1‌ (HO-1) antioxidant pathway, except for PBAE-plasmid NP-loaded microneedles, which did not significantly increase HO-1 expression. Notably, microneedles containing both NPs exhibited superior efficacy in reducing IL-1β and JAK1 levels and upregulating Nrf2 expression compared to formulations with only one NP type. This innovative combination strategy demonstrates promise as a novel therapeutic approach for AD.