Fig. 5

Schematic illustration of the microfluidic device for multicellular tumor spheroids formation and drug screening application; a The overall schematic representation of the microfluidic chip. The bottom left displayed the schematic diagram of tumor spheroids formation on a microwell; b Top and side views of the microfluidic device; c The workflow of multicellular tumor spheroids formation and drug screening-related assay, reprinted with permission from [157]; d Schematic diagram of another microfluidic device, which consists of three tissue chambers (blue) and two microfluidic lines (red) connected to sources and sinks. Tiny communication pores (30 μm minimum diameter) allow the microfluidic lines and tissue chambers to communicate via diffusion and convection of interstitial fluid; e PDMS platform with two devices. The device on the left has been filled with colored dye to highlight the microfluidic channels. The scale bar indicates 3 mm; f The vascular tissue is created in the central chamber while the side chambers are loaded with ECM gels. The pressure and concentration gradients can be created by maintaining differential concentration or pressure in the fluidic lines; g Two days after the device is loaded with endothelial cells and fibroblasts, the endothelial cells form a network of the vessel (Green) in the central chamber. Scale bar shows 100 μm, reprinted with permission from [158]