Long-acting anti-inflammatory injectable DEX-Gel with sustained release and self-healing properties regulates TH1/TH2 immune balance for minimally invasive treatment of allergic rhinitis

Abstract Background Allergic rhinitis (AR) is a prevalent immune-related allergic disease, and corticosteroid nasal sprays serve as the primary treatment for this patient population. However, their short duration of efficacy and frequent administration pose challenges, leading to drug wastage and potential adverse effects. To overcome these limitations, we devised a novel approach to formulate DEX-Gel by incorporating dexamethasone (DEX) into a blend of Pluronic F127, stearic acid (SA), and polyethylene glycol 400 (PEG400) to achieve sustained-release treatment for AR. Results Following endoscopic injection into the nasal mucosa of AR rats, DEX-Gel exhibited sustained release over a 14-day period. In vivo trials employing various assays, such as flow cytometry (FC), demonstrated that DEX-Gel not only effectively managed allergic symptoms but also significantly downregulated helper T-cells (T H ) 2 and T H 2-type inflammatory cytokines (e.g., interleukins 4, 5, and 13). Additionally, the T H 1/T H 2 cell ratio was increased. Conclusion This innovative long-acting anti-inflammatory sustained-release therapy addresses the T H 1/T H 2 immune imbalance, offering a promising and valuable approach for the treatment of AR and other inflammatory nasal diseases. Graphical Abstract