Liposomal steroid nano-drug is superior to steroids as-is in mdx mouse model of Duchenne muscular dystrophy.

Glucocorticosteroids are the most efficacious anti-inflammatory agents and the gold standard treatment in Duchenne muscular dystrophy (DMD). However, their chronic use may lead to severe side effects. We evaluated the use of a novel injectable steroidal nano-drug in mdx mouse model of DMD by comparing the efficacy of nano-liposomes remotely loaded with the steroid prodrug, methylprednisolone hemisuccinate (MPS) with the same steroid as-is, in short (4-weeks) and long-term (58-weeks) treatments. Liposomal-MPS was selectively targeted to the mouse diaphragm, the most dystrophic muscle at early stage of the disease. The bioactivity of the steroidal nano-drug was evidenced by a significant decreased serum TGF-β and reduced diaphragm macrophage infiltration after short-term treatment. In the long-term, the treatment with liposomal-MPS not only demonstrated improved muscle strength and mobility compared to MPS as-is and untreated mdx mice, it also induced lower tibia and lumbar vertebrae osteoporosis indicating much lower bone related adverse effects.