Fluorinated dendrimer-mediated miR-30a delivery regulates the inflammation of macrophages and mitigates the symptoms of rheumatoid arthritis.

Abnormal expression of microRNAs (miRNAs) plays a significant role in the pathogenesis of rheumatoid arthritis (RA), and thus miRNA-based therapy has emerged as a promising approach for the RA treatment. Herein, miR-30a was successfully screened and identified to be an essential mediator for the inflammation of RA. MiR-30a could directly target the Snai1 gene and further regulate the Cad11 expression to inhibit the NF-κB and MAPK signaling pathways, contributing to the anti-inflammatory effect. To enhance the therapeutic outcome of miR-30a, fluorinated polyamidoamine dendrimer (FP) was developed as the carrier to achieve the miR-30a delivery in the mice of collagen-induced arthritis. The carrier FP and miR-30a formed stable nanocomplexes and effectively mediated the transfection of miR-30a to execute the anti-inflammatory response in lipopolysaccharide-stimulated macrophages. Further, the intravenous administration of FP/miR-30a showed obvious accumulation in the inflamed joints and inhibited the inflammatory response via the Snai1/Cad11 axis, thereby contributing to the anti-arthritic efficacy. In addition, the FP/miR-30a nanocomplexes displayed favorable biocompatibility, as they did not cause the damage of organs following the systemic administration. Taken together, our study demonstrated that miR-30a is an effective anti-inflammatory oligonucleotide and the fluorinated dendrimer-mediated miR-30a delivery possesses the potential to be a promising approach for the treatment of RA and other autoimmune diseases.