Figure 1
(a) The schematic and prototype of 96-well 3D microfabricated cellular invasion assays. The proposed device has has three layers, a glass substrate layer, a layer of micro-patterned gold and a layer of PDMS with through holes to form wells. Within each well, the substrate is divided into two regions, a glass circular region for cell seeding with diameters (Ф) of 200 μm, 400 μm and 800 μm, respectively, as well as a surrounding gold region. (b) The device’s working principle. Within each micro well, the gold surface is modified with a self-assembled monolayer of PEG-SH that repels cell adhesion (i). Following cell seeding, cells selectively attach and spread on the fibronectin coated surfaces, forming confluent monolayers (ii,iii). Further cellular proliferation leads to the formation of multilayer cell clusters due to confinement by surrounding PEG molecules (iv). The culture medium in each well is subsequently replaced with collagen solution which forms a 3D invasion matrix upon temperature-induced gelation, thus initiating cell migration (v,vi). Note that in this study, there is a gap between the gold outer boundary and the PDMS inner boundary within each well, which is also used for cell seeding, contributing to the immobilization of 3D temperature-induced matrix. The cellular migrations and invasions in this peripheral areas are not recorded and analyzed.
