Polyanionic Hydrogels as Biomaterials for Tissue Engineering
Hydrogels consist of crosslinked polymer networks and a fluid filling the internal spaces of the network which can hold large amounts of water and thus can undergo large deformation, in contrast to most industrial materials such as metals, ceramics, and plastics, which are dry and hard. 1 Living tissues are highly aqueous gel materials largely composed of biopolymer networks such as polysaccharides. 2 Thus, hydrogels have long attracted considerable attention for various biomedical applications. Polyelectrolyte gel is a charged polymer network with macro ions fixed on the polymer chains and with microcounterions that are localized in the network frame and thus has the ability to swell in water and can absorb a significant amount of water within its structure.