Multidirectional Lithography of Cell-Laden Hydrogels

Controlled microstructuring of cell culture environments is of interest in life science applications such as bioreactor optimization. Here we introduce multidirectional UV lithography of a photoresist consisting of the biocompatible hydrophilic hydrogel PEGDA preloaded with cells. By culturing the cells in sugar solution before adding them to the resist, we enabled refractive index matching between the gel and the cells, thus minimizing spurious light scattering during photostructuring. We created 3D-periodic porous scaffolds of interlocked micropillars of diameter 250 µm and pitch 1 mm, where 1% w/w yeast cells were incorporated inside the solid pillar fraction with high cell viability.