Superabsorbent Ion-Conductive Hydrogels with Predefined Nano/Microscale Geometry and Controlled Swelling Properties for Versatile 3D Cell Culture Scaffolds

This research presents a general method to prepare synthetic polymer-based superabsorbent hydrogels with predefined nano/microscale geometry and controlled swelling properties. Water-soluble synthetic polymer, polyvinyl alcohol (PVA), is homogeneously mixed with crosslinkers in the solution phase, and thermally crosslinked in the solid phase, e.g. films and fibers, while the degree of crosslinking is modulated by controlling mixing ratio, pH, and/or thermal annealing conditions. After shape definition processes, the chemically crosslinked PVA films or nanofibers are modified to break intra/interchain hydrogen bonds through introduction negatively charged functional groups (we named this process as <i>hydrogelification</i>). The resultant superabsorbent hydrogels exhibit high optical transparency and sensitive dimensional change via increasing ionic strength due to its anionic functional groups. Also these hydrogels show tunable swelling/mechanical properties in addition to isotropic expansion of predefined geometry. Particularly, hydrogel nano/microfiber meshes exhibit excellent biocompatibility, superior cell adhesion, and large interfiber spacing, leading to versatile 3D cell culture scaffolds which support not only immortalized cell line cultures but also primary neuronal cell network formation.