Swelling, strength, and biocompatibility of acrylate-based superporous hydrogel hybrids

A hydrogel hybrid of chemically cross-linked hydroxyethyl acrylate interpenetrated with physically cross-linked carboxymethylcellulose was prepared as a superporous structure with swelling rates ranging from a few seconds to minutes depending on the swelling medium. A new method was adopted to evaluate the swelling capacity and rate in superporous hydrogel hybrid using a modified texture analyzer. Based on the extensive data acquisition, swelling data at any time point were obtainable and fit into a Voigt viscoelastic model. Moreover, the two mechanisms by which a superporous hydrogel hybrid swells in an aqueous medium were differentiated and used to estimate the onset of the diffusion-controlled swelling, which was found to be dependent on the actual composition of the swelling medium. A correlation was found between the mechanical strength of the fully swollen hydrogels and their respective swelling force in different swelling media. The concentration of alcohol in the medium was a critical factor in the swelling characteristics and strength of these hydrogels. Two HeLa and mesenchymal stem cells derived from human umbilical cord cell lines were used to evaluate biocompatibility of the prepared hydrogels.