Figure 1.

Commonly used 3D cell culture techniques for HCI. (A) Hanging droplet plate containing 3D spheroids. To generate 3D spheroids, cell suspension is dispensed through the access holes of the hanging droplet plate such that the droplets are attached to the hydrophilic surface. Individual cells are aggregated within hours of incubation due to gravity, forming a single spheroid. (Adapted from [57] with permission of The Royal Society of Chemistry.) (B) Liquid overlay on top of cells in a 96-well plate. The bottom of the 96-wells is coated with non-adhesive polymer in a serum-free medium, which is followed by cell seeding. The 96-well plate is centrifuged to induce cell aggregation and hydrogel in a serum-supplemented medium is overlaid on top of the aggregated cells. (C) Hydrogel matrix mixed with cells in a 96-well plate. Cell suspension is mixed with hydrogel and dispensed in the 96-well plate. Cells naturally form 3D structures within the hydrogel matrix while growing.