FIGURE 6.

Future developments of hiPSC-derived NMD models. Optimization of soluble factor treatments will be needed to improve maturity of MNs, SkM, and NMJs toward their respective in vivo-mimetic phenotypes. Incorporation of biophysical stimulation during cell culture such as electrical stimulation, mechanical stretch, and media agitation are expected to further improve functional maturity of NMJs. Biomaterial design and microfabrication/microfluidics techniques can be applied to generate biomimetic microenvironments for cell growth via controlled presentation of developmentally relevant gradients in growth factors, topography, and stiffness. As the function of native NMJs relies on complex multi-cellular interactions, the ability to incorporate Schwann cells (SCs), endothelial cells (ECs), fibro-adipogenic progenitors (FAPs), and immune system cells (ICs) would improve modeling of in vivo states and our understanding of NMJ physiology and pathology. Incorporation of additional organ compartments sharing culture media with NMJs, such as intestine, gut, and liver will better emulate human drug responses, while adding bone, ligament, cartilage, and fat compartments will allow studies of the organ-organ crosstalk in NMDs. Finally, further miniaturization and standardization of culture systems along with development of non-invasive metabolic and functional readouts will enable establishment of versatile NMD platforms for high-throughput drug discovery research.