Collagen/poly(acrylic acid)/MXene hydrogels with tissue‐adhesive, biosensing, and photothermal antibacterial properties

Abstract The application of collagen‐based hydrogel is severely restricted due to its poor mechanical strength and functional singleness. In this paper, two‐dimensional MXene nanosheets were introduced into collagen/acrylic acid (AA) system, which was polymerized in situ to produce versatile hydrogel (GCol‐MX‐PAA). The tensile stress and compressive stress values of the resultant hydrogel at the MXene concentration of 5 mg/mL reached 211.5 kPa and 7.8 MPa, respectively, which were approximately 4.0 and 1.4 times higher than those of GCol‐PAA. The bonding strength of the hydrogel reached 30.7 kPa in the porcine skin‐adhesive model owing to the large number of free phenolic hydroxyl groups on GCol. Furthermore, GCol‐MX‐PAA could be applied to monitor large and subtle activities of human body due to the excellent electrical conductivity of MXene. Thanks to the outstanding photothermal conversion performance of MXene, the hydrogel could kill E. coli and S. aureus effectively under NIR irradiation. In addition, in vitro cytotoxicity test performed on L929 fibroblasts demonstrated the desirable biocompatibility of GCol‐MX‐PAA. The design strategy in this work gives guidance for the development of multifunctional collagen‐based hydrogel in a wide range of applications. Highlights Versatile hydrogel constructed from GA‐modified collagen, PAA, and MXene. The composite hydrogel displays improved mechanical properties. This hydrogel possesses superior tissue adhesion and strain sensitivity. This hydrogel shows desired photothermal antibacterial property and biocompatibility.