In situ development of self-healing, injectable, glucose and pH-responsive electroconductive composite hydrogels

With the emergence of wearable devices, hydrogel (HGs) materials have been explored for direct and seamless interfacing with the body while integrating multifunctional capabilities. This work presents an in situ gelation route for creating composite poly(ethylene glycol) diacrylate (PEGDA)-based HGs by exploiting borax-catalyzed thiol-acrylate Michael addition and boronate ester crosslinking of 1,2-diols in dithiothreitol. The boronate ester bonds disclose glucose and pH-mediated degradation, followed by the subsequent release of therapeutic compounds in an “on-demand” fashion. Using the same route, we show that the HGs can integrate conductive elements such as gold nanoparticles, poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS), or MXene (Ti_₃C_₂Tx) thereby establishing an electrically active HG network. The resulting HGs can be processed using extrusion-based techniques, yielding enhanced conductivity, stretchability, adhesiveness, self-healing properties, and thermo-responsiveness. In addition, upon glucose absorption and subsequent destabilization, the proposed HG systems generate electrochemical responses across a wide glucose concentration range (from μM to mM), highlighting their potential for integration in wearable point-of-care devices. Finally, an in vitro wound healing assay reveals enhanced wound closure in the presence of the composite HGs, thereby highlighting their potential use in wound management.