Conductive Viologen Hydrogel Based on Hyperbranched Polyamidoamine for Multiple Stimulus-Responsive Drug Delivery

The emergence of precision medicine and personalizedpharmacotherapyhas led to the development of advanced drug delivery systems thatcan respond to multiple stimuli. Conductive hydrogels have excellentelectrical signal responsiveness and drug storage capabilities; however,current conductive hydrogels suffer from poor mechanical properties,low ionic conductivity, and high voltage. Herein, a covalently crosslinkedviologen hydrogel was prepared using electroactive hyperbranched polyamidoamine(EHP) as the crosslinking center in a polymeric network. Attributedto its unique molecular architecture, this hydrogel exhibits improvedmechanical properties (high tensile strength and desirable stretchabilityup to 1280%). Approvable ionic conductivity, biocompatibility, antibacterialproperties, and wearable strain-sensing performance were also disclosed,ascribed to the participation of versatile viologen groups in thehydrogel structure. This hydrogel exhibited high efficiency in drugrelease (81.6%) at a lower voltage of -1.2 V. Moreover, fascinatingpH-stimulus drug release behavior was also demonstrated in both acidicand alkalescent environments owing to the dramatic conformationaltransition of EHP. This work provides a new design strategy for conductivehydrogels for multiple stimulus-responsive drug delivery systems.

Automated summary

This study successfully prepared a conductive crosslinked viologen hydrogel using an electroactive hyperbranched polyamidoamine as the crosslinking center. The hydrogel exhibited improved mechanical properties, desirable stretchability, high ionic conductivity, biocompatibility, antibacterial properties, and wearable strain-sensing performance. It also demonstrated high efficiency in drug release at a lower voltage and pH-stimulus drug release behavior in acidic and alkalescent environments. This work provides a new design strategy for conductive hydrogels in multiple stimulus-responsive drug delivery systems.