Figure 1.

Diverse microfabrication techniques to recreate 3-D ECM microenvironments in vitro. (A) Microfluidics is used to build 3-D sandwiched ECM formed by collagen and Matrigel (i). An aligned collagen fiber zone is established at the surface (ii) [14]; (B) A multiscale vascular system with collagen as ECM is produced by using the 3-D bioprinting technology [63]; (C) Photochemistry is used to build 3-D patterned hydrogels as scaffolds with a range of different geometries (i). The size and shape of the cells is controlled inside microniche chambers (ii). Scale bar: 100 μm [23]; (D) A glucose gradient is established in the microfluidic chip, with collagen as the ECM. The system is used to study the trend of collective invasion of cancer cells. The cartoon of device is shown in (i), and the corresponding 3-D view is shown in (ii) [64]. All figures shown here are reproduced with permission from copyright owner.