Hydrogels as hydrophilic or amphiphilic polymeric networks are fascinating materials of both fundamental and technological interest, with a wide variety of applications based on their ability to absorb large amounts of water and to influence the mass transfer of solutes. They do not dissolve, maintaining a defined shape due to a permanent three dimensional structure. In recent years, the hydrogels are used as specific sorbents and support carriers in biomedical engineering. They are key components of consumer products like diapers, biochemical separation techniques, pharmaceutical delivery systems and medical devices such as artificial organs. Applications of gels in pharmacy and biotechnology (drug delivery matrices, gel-based techniques for protein purification chromatography, gel electrophoresis, and aqueous two-phase extraction) receive particular emphasis. More…