Fig. 4. Uptake of DOX in HT-29 spheroids grown on 5 × 5 pillar array. (A) Composite fluorescence images of 5 × 5 array of HT-29 cell spheroids exposed to DOX. HT-29 spheroids cultured for 5 days were exposed to DOX for 30 min (5 replicates per concentration) and cryosectioned for confocal imaging. Representative images of HT-29 spheroids exposed to 0, 25, 50, 75, or 100 μM DOX are shown in the right panel. Scale bar, 50 μm. (B) Linear relationship between average fluorescence intensity and DOX concentration, showing concentration-dependent uptake of DOX into HT-29 spheroids.
