Figure 1.

Microgrooved hydrogel and pillar methods for myoblast alignment. (Ai) Fabrication process of gelatin microgrooved substrate. (ii) Myotubes cultured on micromolded gelatin hydrogels, showing the tissue as a flat monolayer. (iii) Myotubes with visible sarcomeres after 3 weeks of differentiation: blue nuclei, red sarcomeric α-actinin (Reproduced with permission from ref (34). Copyright 2016 Springer Nature CCBY-NC-ND 4.0). (B) Muscle tissue development on GelMA hydrogel anchored around two hydrogel pillars. (i) Brightfield images showing an increase in cell growth, alignment, and compaction as a function of days of culture. (ii) Immunofluorescent staining images at day 12 of myosin heavy chain (MF20) (green), nuclei (blue), and F-actin (red) depicting highly matured muscle tissue. (iii) Cross-sectional image illustrating muscle-like fascicular structure. (iv) High magnification (100×) image depicting the arrangement of nuclei on the periphery of myotubes (white arrows). Scale bars: (i) 150; (ii) 50; (iii and iv) 20 μm (Reproduced with permission from ref (95). Copyright 2017 Royal Society of Chemistry). (Ci) nSKM-laden fibrin hydrogel in a silicone mold anchored on each end to velcro pillars. (ii) Immunostaining of α-actinin (green) and nuclei (red) at day 14, showing highly aligned multinucleated myotubes with ubiquitous cross-striations (Reproduced with permission from ref (96). Copyright 2011 Elsevier).