Figure 1:

Experimental Timeline. To study the effects of DEX on the early and late stages of proliferation and early stage of differentiation, DEX was supplemented from days 0–4, days 3–5, and days 5–7 at a 25 nM dose. Sustained addition of 10 nM DEX, which showed optimal SMU function in our previous study, was used as a control. Throughout the SMU fabrication process, myogenesis was analyzed with immunostaining for proliferation with BrdU and MyoD, differentiation with myogenin, myotube fusion and structural maturation with α-actinin, and myotube size and density with light microscopy. Following 3-D SMU formation, isometric tetanic force production was measured to assess functionality. MGM stands for Muscle Growth Medium, MDM for Muscle Differentiation Medium.