Fig 2. Growth rate of cell spheroids exposed to the different AuNPs for 72 hours, normalized to the growth rate of control spheroids cultured without AuNP.

a)AuNS, b) AuNS-oligos, and c)AuNR. The number of spheroids used for calculating the growth rate for each condition ranged from 5 to 8. The ‘*’s in the figure indicates a positive T-test testing the hypothesis that the normalized growth rate is less than 1 at a significance level of 0.001.