Table 3.

Main materials and assays to generate 3D muscular models.

Usable extracellular matrices (Penton)102	• Matrigel: excellent in short-term studies; myoblast differentiation variability in long-term expansion. Not well tolerated for clinical applications. • Laminin 211: well tolerated because native isoform in resting skeletal muscle. Low efficiency in myoblast proliferation and differentiation. • Laminin 521: fine matrix for short and long-term cell maintaining. Well tolerated substrate to expand myoblasts for cellular therapy in clinical studies.
Co-cultures, and chemical stimulations (Morimoto)103	• Neurospheres derived from neural stem cells, kept in contact with skeletal muscle fiber bundles. Efficient formation of neuromuscular junctions. • Electrical stimulation by glutamic acid addition. Increased unidirectional contraction in the neuron–muscle constructs.
Co-cultures and electrical stimulations (Demestre)104	• Motoneurons and myotubes derived from the same human iPSC cell line. Early aggregation of acetylcholine receptors in neuromuscular junctions. • Electrical field stimulation performed with a stimulator. Contraction as a consequence of acetylcholine release and establishment of an action potential.
Anchoring structures (Juhas)105	• Committed myogenic cells undergone to rapid myotube and bundle formation. • Muscle bundles anchored to polydimethylsiloxane wells, enhancing the final maturation with development of quiescent satellite cells and a basal lamina.
Hydrogels and specific media (Rao)106	• Committed myogenic cells embedded into fibrin hydrogels and cultured in 3D tissue media. • Skeletal muscle constructs contracting if electrically or chemically stimulated. Vascularization and perfusion if implanted.
Biocompatible materials and nonmuscular cellular types (Maffioletti)107	• Patient-derived human iPSCs seeded in biocompatible fibrin-based hydrogels, under tension to induce myofiber alignment. • Four lineage isogenic system, including vascular endothelial cells, pericytes and motoneurons, supporting vascularization, perfusion and innervation of 3D artificial muscular models.

3D, three-dimensional; iPSC, induced pluripotent stem cell.