Preparation and Characterization of AgNWs Conductive Hydrogel With High Mechanical Performance, High Electrical Conductivity, and Biocompatibility

Hydrogel scaffolds incorporating conductive fillers have garnered significant interest due to their potential applications in neural tissue repair and regenerative medicine. However, most conductive fillers have adverse effects on the mechanical properties of hydrogel networks. In the present study, a novel polyacrylamide/alginate (PAAm/Alg) assembled with conductive silver nanowires (AgNWs) composite hydrogel was developed through photopolymerization and crosslinking methods. The chemical structure, morphology, mechanical properties, conductivity, porosity, swelling rate, adhesive strength, thermal stability, in vitro biodegradation, and biocompatibility of the prepared hydrogel samples were investigated. The PAAm/Alg-AgNWs hydrogels exhibited uniform pore structure distribution, high porosity and water absorption, improved mechanical and conductive properties, good thermal stability, and adequate biodegradability. In particular, the 0.4 wt% AgNWs conductive hydrogel exhibited excellent conductivity of 0.618 S/m and a high Young's modulus of 43.6 kPa, along with good electrical durability and stability over ten cyclic loading. Moreover, the abundant hydrophilic groups in the hydrogel make it have good adhesion properties at different interfaces. Compared with the PAAm/Alg hydrogel, the incorporation of AgNWs enhanced the material's roughness, facilitating cell adhesion, viability, and proliferation. These results showed that the AgNWs assembled into the PAAm/Alg polymers endowed the hydrogel with high electrical conductivity, while excellent mechanical strength and biocompatibility, indicating an attractive conductive substrate for further studies on neural tissue repair and regeneration.