Polyacrylamide Hydrogels as Versatile Biomimetic Platforms to Study Cell-Materials Interactions

Polyacrylamide (PAAm) hydrogels are widely adopted as 2D-model soft substrates for investigating cell-material interactions in a controlled in vitro environment. They offer facile synthesis, tunable physico-chemical properties, diverse biofunctionalization routes, optical transparency, mouldability in a range of geometries and shapes, and compatibility with living cells. PAAm hydrogels can be engineered to reconstruct physiologically relevant biointerfaces, like cell-matrix or cell–cell interfaces, featuring biochemical, mechanical, and topographical cues present in the extracellular environment. This Review provides a materials science perspective on PAAm material properties, fabrication, and modification strategies relevant to cell studies, highlighting their versatility and potential to address a wide range of biological questions. Current routes are presented to integrate cell-instructive features, such as 2D patterns, 2.5D surface topographies, or mechanical stiffness gradients. Finally, the recent advances are emphasized toward dynamic PAAm hydrogels with on-demand control over hydrogel properties as well as electrically conductive PAAm hydrogels for bioelectronics.