Establishment of a method for engineering of microstructures in hepatic spheroids

Abstract

The objective of this study was to establish a method enabling us to control microarchitectures of spheroids. We injected 1 μl of culture medium suspending Hep G2 cell and alginate hydrogel beads into a 3% methylcellulose medium. The beads were 20 μm in diameter. The injected cells and beads were rapidly aggregated in 10 min, and formed hybrid spheroids in 24 h. Microchannel structures were constructed by enzymatic digestion of the beads. In a different experiment, injection of Hep G2 cells and HUVECs resulted in forming microstructures by autonomous cellular rearrangement. Another type of micropattern was able to be obtained by injecting HUVECs and small-spheroids. Dissolved polymeric molecules like ECMs were also possible to be concentrated together with Hep G2 cells. The amount of polymeric molecules existing inside of the spheroids was tunable by changing its concentration. These data show that our method is useful to engineer microarchitectures of spheroids.