Figure 8: In vivo magnetofection in mouse skeletal muscle: (A) Our magnetofection protocol was evaluated in 10-month old C57BL/6 mice. Animals were anesthetized and positioned ventrally on the operating table with both hindlimbs extended and gently immobilized. Finally a 1-cm long incision was made to access the posterior muscular compartment. (B1, B2 and B3) Six days after magnetofection, freshly isolated Soleus revealed a brown area beneath the muscle surface where the RAd-MNPs were injected. (C1 and C2) Naked RAd-GFP resulted in transduction of only mononucleated cells with no GFP positive myofibers. (D1-D4) After magnetofection with RAd-MNPs complexes, GFP positive myofibers were noticeable and clearly differ from the surrounding tissue auto fluorescence. (D5 and D6) Co-localization of GFP expression and magnetic nanoparticles (Atto550PEI-Mag2 with red fluorescence) within the same myofiber.