Figure 7.

Microdevices for tumour-on-a-chip studies. (a) Establishment of vascularized micro-organs (VMOs). (i) A schematic depicts the microfluidic platform of the VMO, which consists of a thick layer of PDMS with patterned tissue chambers and microfluidic channels, bonded on top of thin PDMS membrane and a glass coverslip. The cell–ECM suspension is injected through the gel-loading ports at either end of the tissue chamber. The four media reservoirs are attached to the inlets and outlets of the microfluidic channels. (ii) A depiction of a representative tissue chamber at day 7 with a fully developed vascular network. Transduced endothelial cells, shown in red, are migrating out and fusing with microfluidic channels. This platform is used later in the study to establish a human colon cancer micro-tumour. Adapted from [124] with permission from Nature Publishing Group. (b) A human breast cancer-on-a-chip. (i) A depiction of DCIS (carcinoma) in a mammary duct, with basement membrane, epithelium, stroma and capillary blood flow. Adapted from [13] with permission from the Royal Society of Chemistry. (ii) An image showing the interaction between breast cancer cells and an artificial microvessel embedded in a microfluidic tumour-on-a-chip device. Adapted from [98] with permission from the American Association for Cancer Research. (c) Design of microfluidic chip for tumour spheroid–fibroblast co-culture. This chip is used for three-dimensional co-culture of human colorectal cancer cells and fibroblasts. There are four units per chip and seven channels per unit for loading with either cells or media. The bottom-left shows in detail a cell-loading channel. Adapted from [179] with permission.