mmu-miR-449a-5p antagomir is a chemically modified complementary single strand of mature miRNA, with methoxy modifications across the entire chain. It features two and four thiol modifications at the 5' and 3' ends, respectively, and is linked to a high-affinity cholesterol modification at the 3' end. The miRNA antagomir inhibits the function of miRNA by specifically binding to the mature miRNA, thereby preventing its complementary pairing with target genes. Compared to a miRNA inhibitor, the miRNA antagomir demonstrates greater stability and inhibitory efficiency in animal studies, and it more readily penetrates cell membranes and tissue gaps to accumulate in target cells.