High-throughput investigation of complex cellular behavior in a mechanically-tunable 3D hydrogel co-culture system prepared via programmable multilayer printing

Abstract

Hydrogels are widely used as a 3D cell coculture platform, as they can be tailored to provide suitable microenvironments to induce cellular phenotypes with physiological significance. Herein, a mechanically- tunable 3D hydrogel-based co-culture system was fabricated via programmable multilayer photolithography in an efficient and scalable manner, which consists of a cell encapsulated inner microgel array and an outer hydrogel overlay. Through the high-throughput investigation of both individual hydrogel mechanics and mechanical gradients generated at their interface, it was demonstrated that macrophage phenotypical changes (i.e. proliferation, spheroid formation and Mϕ polarization) were substantially influenced by the direction and degree of mechanical gradient, as well as the presence of co-cultured fibro- blasts in the vicinity. Furthermore, the paracrine effect between the macrophages in different microgels was clearly mediated by their inter-distance.