Fig. 1

Effect of ferritin incorporation on neurosphere formation. a Schematic illustration and timeline of the experiments. Ferritin nanoparticles were incorporated into neurospheres by addition to the culture media (0.02, 0.1, and 0.3 mg/mL) every 2 days during culture to expand hfNSCs. Subsequently, neurospheres were plated onto cell culture plates coated with fibronectin and allowed to differentiate spontaneously for 4 days. Medium was exchanged every 2 days. b Neurospheres of hfNSCs cultured with or without ferritins were stained with calcein-AM (for live cells; green) and ethidium homodimer-1 (for dead cells; red) after 6 days of culture for self-renewal and expansion. Scale bar = 500 μm. c Average size of generated hfNSC neurospheres in each group after 6 days of culture (n = 40–45, **p < 0.01 versus No ferritin group). d Relative viability of hfNSCs in each group after 6 days of culture under self-renewal conditions, evaluated by MTT assay (n = 4, *p < 0.05 and **p < 0.01 versus No ferritin group)