Super Mechanical Stimuli Responsive Hydrogel: Dynamic Cues for Cell Applications

In this work, we fabricated a thermosensitive hydrogel based on NIPAM that incorporated an oxygen-permeable hyaluronic acid (HA) polysaccharide unit. The interpenetrating network (IPN) of NIPAM-HA-MA hydrogel was fabricated by using an ultraviolet (UV) cross-linking process. Importantly, we explored the real behavior kinetics of the hydrogel via the mechanical properties of Young's modulus and the shear strain. The mechanical properties were reduced when the temperature was raised from 25 to 35 °C, and lower temperatures increased the rigidity of the IPN gel. This dynamic change occurred because of NIPAM's thermosensitive character. Further, IPN hydrogel exhibits good transparency with the incorporation of MA-HA and this stimuli-responsive hydrogel was biocompatible with a human dermal fibroblasts cell line (HDF). The cells adherence was densest when the temperature reached 37 °C and was reduced when the temperature was lowered to 25 °C. We envision using such hydrogels as mimics of cell-instructive biomaterials in tissue engineering applications.