ABSTRACT
Hydrogels are produced from cross-linked hydrophilic polymers to give three-dimensional mesh structures or networks. By appropriate choice of synthetic conditions, gels can be formed which are either able to hold therapeutic molecules entrapped within the mesh structure or to act as a gating barrier [1]. Immersed in an aqueous solution, these polymeric networks are capable of imbibing large amounts of water or biological fluids [2,3]. However, the internal cross-links prevent complete dissolution and constrain the degree of swelling and hence the release rate of solutes.
