Superparamagnetic nanoparticles as potential <i>drug delivery</i> systems for the treatment of Duchenne muscular dystrophy

This study aims to use superparamagnetic iron oxide nanoparticles (SPIONs), specifically magnetite (Fe₃O₄), to deliver deflazacort (DFZ) and ibuprofen (IBU) to Duchenne muscular dystrophy-affected (DMD) mouse muscles using an external magnetic field. The SPIONs are synthesized by the co-precipitation method, and their surfaces are functionalized with L-cysteine to anchor the drugs, considering that the cysteine on the surface of the SPIONs in the solid state dimerizes to form the cystine molecule, creating the Fe₃O₄-(Cys)₂-DFZ and Fe₃O₄-(Cys)₂-IBU systems for <i>in vivo</i> tests. The Fe₃O₄ nanoparticles (NPs) were characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, powder X-ray diffraction (PXRD), transmission electron microscopy (TEM), dynamic light scattering (DLS), and magnetic measurements. The results show that the SPIONs have an average crystallite size of about 8 nm in the solid state and a hydrodynamic size of about 120 nm, which is suitable for biological applications in aqueous dispersion. The nanoparticles exhibit superparamagnetic behavior at room temperature and spherical-close morphology. In addition, vibrational modes characteristic of the functional groups of the molecules anchored to the surface of the SPIONs are identified. Data from blood tests of <i>mdx</i> mice after seven consecutive days of treatment with nanoparticles confirm the non-toxic nature of the system and show an improvement in DMD, with normal levels of liver and kidney enzymes and a decrease in creatine kinase protein.