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

Abstract

The emergence of precision medicine and personalized pharmacotherapy has led to the development of advanced drug delivery systems that can respond to multiple stimuli. Conductive hydrogels have excellent electrical signal responsiveness and drug storage capabilities; however, current conductive hydrogels suffer from poor mechanical properties, low ionic conductivity, and high voltage. Herein, a covalently crosslinked viologen hydrogel was prepared using electroactive hyperbranched polyamidoamine (EHP) as the crosslinking center in a polymeric network. Attributed to its unique molecular architecture, this hydrogel exhibits improved mechanical properties (high tensile strength and desirable stretchability up to 1280%). Approvable ionic conductivity, biocompatibility, antibacterial properties, and wearable strain-sensing performance were also disclosed, ascribed to the participation of versatile viologen groups in the hydrogel structure. This hydrogel exhibited high efficiency in drug release (81.6%) at a lower voltage of −1.2 V. Moreover, fascinating pH-stimulus drug release behavior was also demonstrated in both acidic and alkalescent environments owing to the dramatic conformational transition of EHP. This work provides a new design strategy for conductive hydrogels for multiple stimulusresponsive drug delivery systems.

Harnessing the potential of hydrogels for advanced therapeutic applications: current achievements and future directions

“… 468 , 469 More importantly, hydrogels, with numerous modifiable sites that can be used for fabricating physicochemical interactions, also accommodate multiple drug delivery. 470 , 471 This capability is particularly beneficial in oncological applications, where the synergistic action of combined therapeutics is necessary to achieve optimal treatment outcomes. Further, the design of hydrogels can simultaneously include different encapsulation techniques—ranging from passive encapsulation to active tethering of drugs to the hydrogel’s structure, or stimuli-responsive elements, leading to the asynchronous release of different drugs and thus paving the way for precise spatiotemporal control over drug delivery.…”

Viologen Cross-Linked Chitosan Hydrogel as Biobased Antiseptic Surface-Coating Materials

“…We have selected an alkylated quaternary pyridinium derivative, commonly known as viologen. − Viologen has been massively used owing to its multifaceted properties (ionic conductivity, photochromic and electrochromic properties, antibacterial properties, and so on). Its backbone has been included in dendrimers, polymers, and covalent organic framework, and more recently, it has been also embedded in hydrogels and/or grafted on other related nanostructures. − In most cases, these materials showed electro-sensitive properties ( e.g. , conductive hydrogels suitable for transdermal bioelectronics devices, wound dressing, electro-stimulated drug delivery, etc.)…”

“…, conductive hydrogels suitable for transdermal bioelectronics devices, wound dressing, electro-stimulated drug delivery, etc.) coupled to good antibacterial activity, with a more intriguing structure–reactivity relationship. ,,− ,− In a complementary fashion, mechanically tailorable double network chitosan-based hydrogels have also emerged as multitask functional biomaterials. − …”