Highly stretchable cell-cultured hydrogel sheet

Abstract

A free-standing cell-cultured hydrogel sheet with stretchability was prepared for an in vitro cellular assay with mechanical stimulation. The anti-fouling surface of the stretchable double network (DN) hydrogel composed of poly(2-acrylamido-2-methyl-1-propanesulfonic acid sodium salt) (PNaAMPS) and poly(N,N-dimethylacrylamide) (PDMAAm) was modified as the cell adhesive by additional polymerization of PNaAMPS at the surface region of the DN hydrogel in the depth of around 170 μm, while preserving the original stretchability and molecular permeability. The mechanically stable and flexible hydrogel sheet holding the culture medium has the advantage that it can be handled with tweezers in air, and cells adhered on the sheet maintain physiological activity during transportation of the film for in vitro assays. The stretchability of the free-standing culture sheet allows for the observation of the Ca²⁺ response of epidermal keratinocytes upon mechanical stimulation.