A) Confocal images of MSCs encapsulated within alginate microgels of 0.41 (top) and 1.00 kPa (bottom) stiffness. Blue, nuclei; green, alginate; red, actin; scale bar, 10 μm. ALP expression for cells in the corresponding groups.[46] B) MSCs encapsulated within 5 and 7.5% w/v TG-PEG hydrogels. ALP expression of MSCs in the corresponding groups after culturing 7 days in differentiation medium.[123] Images of single-cell microgels and box plot of ALP expression are reproduced with permission.[46] Copyright 2016, Springer Nature. Images of single-cell microgels and ALP expression percentage plot are reproduced with permission.[123] Copyright 2017, Royal Society of Chemistry.