Neuronal differentiation of human placenta-derived multi-potent stem cells enhanced by cell body oscillation on gelatin hydrogel

Gelatin is a biocompatible material commonly employed in biomaterial design and tissue engineering. However, there is currently a lack of research into the development of gelatin hydrogels for facilitating specific lineage development of stem cells. In this study, the neuronal differentiation of human placenta-derived multi-potent (stem) cells was systematically optimized through the engineering of the gelatin hydrogel properties. The swelling ratio of Type A or Type B gelatin hydrogel changes during hydrogel formation in the gelatin concentration ranges from 16 to 6 wt%. In general, placenta-derived multi-potent (stem) cells effectively adhere on both, acidic and basic gelatin hydrogels with different swelling ratios as shown by the high attachment ratio of around 80%. Interestingly, adhered placenta-derived multi-potent (stem) cells had significant cell body oscillations on either 6 or 10 wt% gelatin hydrogels during the first 3 h of cell seeding. For placenta-derived multi-potent (stem) cells pre-cultured on 6 and 10 wt% gelatin hydrogel for either 2 or 12 h and subjected to 3-isobutyl-1-methylxanthine to induce neuronal differentiation, the periodic contraction and extension of placenta-derived multi-potent (stem) cells pre-cultured for 2 h successfully directed the cells into neuron-like lineages. In contrast, the lack of cell body oscillation restrained the placenta-derived multi-potent (stem) cells pre-cultured for 12 h from differentiating into neuronal cells on the same gelatin hydrogels in response to 3-isobutyl-1-methylxanthine stimulation. Overall, the possibility of engineering the properties of gelatin hydrogel to trigger stem cell development into a neuronal lineage through cell body oscillations was clearly demonstrated.