RIGI and melanoma: Magnetic properties of TTX enable its detection by magnetic resonance imaging (MRI) supporting the concept of image-guided therapy.<h4>Procedures</h4>A single-stranded anti-miR-21 5'-triphosphate RIG-I agonist was conjugated to the dextran coat of the nanoparticles through disulfide bonds producing TTX-RIGA-miR-21 and tested in vitro and in vivo in B16-F10 melanoma model.