Despite their simplicity, monolayer cell cultures are not able to accurately predict
drug behavior in vivo due to their inability to accurately mimic cell-cell and cell-matrix interactions. In contrast, cell spheroids are able to reproduce these interactions and thus would be a viable tool for testing
drug behavior. However, the generation of homogenous and reproducible cell spheroids on a large scale is a labor intensive and slow process compared to monolayer cell cultures. Here, we present a droplet-based
microfluidic device for the automated, large-scale generation of homogenous cell spheroids in a uniform manner. Using the microfluidic system, the size of the spheroids can be tuned to between 100 and 130 μm with generation frequencies of 70 Hz. We demonstrated the
photothermal therapy (PTT) application of
brain tumor spheroids generated by the
microfluidic device using a reduced
graphene oxide-branched
polyethyleneimine-
polyethylene glycol (rGO-
BPEI-PEG) nanocomposite as the PTT agent. Furthermore, we generated uniformly sized neural stem cell (NSC)-derived neurospheres in the droplet-based
microfluidic device. We also confirmed that the neurites were regulated by
neurotoxins. Therefore, this droplet-based
microfluidic device could be a powerful tool for
photothermal therapy and
drug screening applications.