After first testing whether an miR-221-3p agomir—a chemically modified double-stranded small RNA that mimics endogenous miR-221-3p—would promote wound healing in a mouse model of diabetes, we examined the molecular mechanisms underlying the regulation of the DYRK1A gene by miR-221-3p through in vitro and in vivo experiments. This evidence concerns the gene DYRK1A and diabetes mellitus.