FIG. 5.

Retrieval sample processing, in-vivo MC38 tumor sample. (a) The microdevice and adjacent tissue specimen is retrieved together as shown in the schematic (left) and actual sample image (right). Here, 10–20 lm thick slices are acquired at 5 discrete cross-sectional levels (as numbered), corresponding to ten distinct areas of drug release. (b) Representative microscopic analysis at three different levels. Fluorescence microscopy shows doxorubicin drug distribution (white arrows) 180° apart into spatially discrete tissue regions, and the corresponding cleaved caspase 3 (CC3) stained slides demonstrate apoptotic tissue response (black arrows). Tissue regions not exposed to drug remain viable and do not demonstrate fluorescent signal or apoptosis (asterisks). Spatial correlation between the drug release and apoptotic response at all levels indicates therapeutic efficacy.