Injectable electroactive hydrogels formed via host-guest interactions

Injectable conducting hydrogels (ICHs) are promising conductive materials in biomedicine and bioengineering fields. However, the synthesis of ICHs in previous work involved chemical cross-linking, and this may result in biocompatibility problems of the hydrogels. We present the successful synthesis of ICHs via noncovalent host-guest interactions, avoiding the side effect of covalent chemical cross-linking. The ICHs are based on the γ-cyclodextrin dimer as the host molecule and tetraaniline and poly(ethylene glycol) as the guests in a synthetic well-defined hydrophilic copolymer. The sol-gel transition mechanism of the in situ hydrogel is thoroughly investigated. This novel synthesis approach of ICHs via supramolecular chemistry will lead to various new biomedical applications for conducting polymers.