Hydration Effects Driving Network Remodeling in Hydrogels during Cyclic Loading

In complex networks and fluids such as the extracellular matrix, the mechanical properties are substantially affected by the movement of polymers both part of and entrapped in the network. As many cells are sensitive to the mechanical remodeling of their surroundings, it is important to appreciate how entrapped polymers may inhibit or facilitate remodeling in the network. Here, we explore a molecular-level understanding of network remodeling in a complex hydrogel environment through successive compressive loading and the role that noninteracting polymers may play in a dynamic network. We find that this is a highly localized and time-dependent effect, with one of the major driving factors of hydrogel matrix remodeling the interaction and movement of water within the network in calcium-cross-linked alginate. Our results suggest a more general mechanistic understanding of hydrogel remodeling, with implications for tissue transformations in disease, biomaterials, and food science formulation.