Fast near infrared light response hydrogel as medical dressing for wound healing

Abstract Fast‐response smart hydrogels with combination of appropriate mechanical strength, self‐healing and tissue adhesiveness ability, and controllable drug release performance are highly desired as wound dressing practice. Herein, a novel dual‐crosslinking hydrogel with gold nanorods (AuNRs) well dispersed in its polymer network, D‐hydrogel@AuNR, was constructed via ultraviolet light initiated radical copolymerization of acrylamide (AM), isopropylacrylamide (NIPAAM), and dopamine methacrylamide (DMA) in a complex solution of AuNRs and cysteamine‐grafted oxidized sodium alginate (OSA‐SH). The produced D‐hydrogel@AuNR exhibits fast response to the near infrared light (NIR, 808 nm) exposure and a cumulative release level of encapsulated gentamicin sulfate (GS) up to 75% within 60 s laser irradiation. The dual‐crosslinking network that the first MBA crosslinked P(AM‐co‐NIPAAM‐co‐DMA) network and the second imine bonded network makes the tensile stress and tensile strain of D‐hydrogel@AuNR could reach up to 397.0 k Pa and 240%, respectively. Moreover, the received D‐hydrogel@AuNR also exhibits remarkable self‐healing ability and excellent cell affinity and tissue adhesiveness. These desirable properties of D‐hydrogel@AuNR together make it an appropriate candidate for practical wound dressing under different biomedical conditions.