Organ-on-a-chip model of ovarian cancer vessel-platelet cross talk. (A) A human cancerous ovary with an injured blood vessel adjacent to tumors, with transmigrating blood cells. This interface is modeled with the OvCa-Chip. (B-C) Cross section of an OvCa-Chip. Two fluidic chambers (red, vessel; blue, cancer cells) in an adjacent superimposed position. (D) Computer-aided design showing the components of OvCa-Chip assembly in detail. The device was fabricated with PDMS soft lithography, with overlaid microchannel compartments bonded to each other with a microporous PDMS membrane between. (E) Microscopy of OvCa-Chip (center) showing human ovarian A2780 tumor cells cultured on the upper microchannel (top) and a human primary-endothelial-cell–formed vessel inside the lower channel (bottom). Bars represent 100 µm. (F) Confocal fluorescence micrograph shows a cross section of the OvCa-Chip, with spheroidal A2780 ovarian cancer cells (red, anti-ZO1) cocultured with primary endothelial cells (green, VE-cadherin) that form continuous monolayers and cover all 4 sides of the lower microchannel, creating a blood-perfused vessel. The tumor-vascular tissue interface distance shown in the cross-sectional 3D view is 10 µm. Platelets are perfused into the vascular lumen of the chip. Bars represent 100 µm.