Nanocomposite hydrogels of LAPONITE® mixed with polymers bearing dopamine and cholic acid pendants

Abstract

A nanocomposite hydrogel system was formulated by mixing LAPONITE® in water with a terpolymer based on N,N′-dimethylacrylamide and comonomers bearing natural compounds dopamine and cholic acid as pendant groups. The formation of such hydrogels is induced by the reversible interfacial binding between the dopamine units and LAPONITE® in combination with self-assembly driven by the cholic acid pendants. These hydrogels may be dissociated by the addition of β-cyclodextrin or Fe³⁺ ions. This kind of nanocomposite hydrogels may be easily formed by a simple mixing of a polymer and a clay, without the necessity of in situ polymerization. The softness and modest mechanical properties of these hydrogels make them interesting candidates in certain biomedical and pharmaceutical applications.