Fig. 1

IV injection of MSNPs biodistribute in dystrophic muscles of mdx mice but not normal muscle tissues in wide type mice. A and B Ex vivo NIR fluorescence imaging of muscles and organs at 24 h after animals received a single IV injection of NIR-labeled lipid coated 70 nm MSNPs (50 mg/kg). NIR fluorescence intensity at ROIs was used to quantify the nanoparticle content in different muscles and organs. Data represent mean ± SEM (n = 3). *P < 0.05, 2-tailed Student’s t test. C-middle Masson’s Trichome staining of TA and Gastroc in 3-month old male C57BL/6, mdx mice and mdx-D2 mice to demonstrate the level of fibrosis with collagen deposit (blue color) in muscles of the different mouse models. Bars represents 100 μm. C-bottom Relative biodistribution of NPs at muscle sites in C57BL/6 WT and different DMD mouse models at 24 h after received IV injection of NIR labeled NPs. The fluorescence intensities of muscles were normalized to the liver for each animal. Data represent mean ± SEM (n = 3)