Dexamethasone Acetate‐Loaded PLGA Nanospheres Targeting Liver Macrophages

Abstract Glucocorticoids are potent anti‐inflammatory drugs, although their use is associated with severe side effects. Loading glucocorticoids into suitable nanocarriers can significantly reduce these undesirable effects. Macrophages play a crucial role in inflammation, making them strategic targets for glucocorticoid‐loaded nanocarriers. The main objective of this study is to develop a glucocorticoid‐loaded PLGA nanocarrier specifically targeting liver macrophages, thereby enabling the localized release of glucocorticoids at the site of inflammation. Dexamethasone acetate (DA)‐loaded PLGA nanospheres designed for passive macrophage targeting are synthesized using the nanoprecipitation method. Two types of PLGA NSs in the size range of 100–300 nm are prepared, achieving a DA‐loading efficiency of 19 %. Sustained DA release from nanospheres over 3 days is demonstrated. Flow cytometry analysis using murine bone marrow‐derived macrophages demonstrates the efficient internalization of fluorescent dye‐labeled PLGA nanospheres, particularly into pro‐inflammatory macrophages. Significant down‐regulation in pro‐inflammatory cytokine genes mRNA is observed without apparent cytotoxicity after treatment with DA‐loaded PLGA nanospheres. Subsequent experiments in mice confirm liver macrophage‐specific nanospheres accumulation following intravenous administration using in vivo imaging, flow cytometry, and fluorescence microscopy. Taken together, the data show that the DA‐loaded PLGA nanospheres are a promising drug‐delivery system for the treatment of inflammatory liver diseases.