Biocompatible conductive hydrogels based on dextran and aniline trimer as electro-responsive drug delivery system for localized drug release.

Dextran with good biocompatibility and degradability shows great potentials for drug delivery and tissue engineering applications. Electro-responsive drug delivery system can provide on-demand and localized drug release. However, dextran-based conductive hydrogel with electrical stimuli responsiveness as drug delivery system has not been reported. Herein, we designed and fabricated a kind of biocompatible biodegradable conductive hydrogel system with the property of electro-responsiveness as a new smart drug delivery system for localized drug release. These series of hydrogels were synthesized by mixing dextran and electroactive aniline trimer with hexamethylene diisocyanate as crosslinker to form hydrogel network. These series of hydrogels exhibited stable rheological property and controllable swelling ratio. These hydrogels showed good conductivity and desirable electric stimuli ability to control drug release. Furthermore, this kind of hydrogel was controlled by external electrical stimuli to generate a kind of "on-off" precise drug release system. When extra voltage was applied, they released more drug intelligently and less drug molecule without external stimuli. The hydrogel showed good cytocompatibility and in vivo biocompatibility by using H&E staining and Toluidine blue staining. All together, these results indicated that these series of biocompatible conductive dextran-based hydrogels were promising candidates as smart drug delivery systems in future biomedical field.