FIG. 1.

Creation of two-layer microfluidic device. (a) Representation of AutoCAD layout of the device. The dimensions of the center channel (purple) are 5.3 mm length, 2 mm width, and 180 μm height. Side channel (blue) heights were 100 μm. Star-shaped microposts (yellow) were spaced 5 μm apart to separate the channels and prevent crossing of extracellular matrix from one channel to another. Not to scale. (b) Schematic close-up depiction of the functioning device. The center channel is filled with extracellular matrix (purple), containing the spheroid (green) and fibroblasts (red). The punch-hole through which the spheroid enters the device is outlined as a faint, dashed circle. In a side channel, endothelial cells (light blue) have formed a barrier on the microposts to act as a barrier membrane for any cancer cells trying to extravasate from the microenvironment. Not to scale. (c) Cross section view of the device as depicted in (b). Not to scale. (d) Image of a microbioreactor prior to loading with ECM. The blue fluid was used to emphasize outline of channels. The red arrow denotes the hole by which a spheroid is introduced into the ECM-loaded device.