Hydrogels: Structure starts to gel

The development and use of new generation of hydrogels are discussed. Hydrogels are formed by crosslinking polymer chains such as physical, ionic or covalent interactions and are well known for their ability to absorb water. They are used in a number of areas including devices, drug delivery and regenerative medicine. They are widely used as three-dimensional cell and tissue culture environments as they are excellent mimics in the in vivo state. Internal spaces created in hydrogels can be used to store cells or drugs and the three-dimensional structure of actual tissues can be mirrored in the gel. The major challenge in the synthesis of these multilayered hydrogels is controlling the kinetics of gelation such that polymer entanglement does not occur. The formation of layered gels, with inter-membrane spaces in which to store biologically active compounds, is promising for complicated delivery profiles.