关键词：聚电解质水凝胶；三维网络；生物医学
摘 要：Polyelectrolyte hydrogel is a three dimensional networks forming by charged polymer chains. The hydrophilic networks capable of imbibing large amount of water or biological fluids, mimics biological tissues. Because of this nature, great attention was devoted to these systems for biomedical applications by tuning the physicochemical properties with varying the degree of crosslinking either by physical or chemical or physical-chemical means. Numerous approaches have been investigated for formulation of polyelectrolyte hydrogels. In this chapter, an attempt was made to narrate the synthetic and natural materials and their mechanism to form cross-linked polyelectrolyte hydrogels. It was also tried to explain the importance of ionotropic gelation and polyelectrolyte complexation approaches, as these methods show great promise as a tool for the development in their application process. For further understanding in this area, a mathematical model was introduced to describe the thermodynamic behavior of polyelectrolyte hydrogels and derives conditions for thermodynamic phase equilibrium; the physical and chemical characterization of hydrogels, as well as special considerations that need to be made when characterizing polyelectrolyte hydrogels, were also discussed. In the end, a number of biomedical applications of polyelectrolyte hydrogel were given, such as in controlled release systems, different types of tissue reconstitution, for the enzyme and protein separations, etc.