GQDs-ε-PL and GQDs-ε-PL-based self-healing hydrogel: Synthesis, characterization and in vitro chemo-photothermal combined antibacterial

Surface amino-rich GQDs-ε-PL is prepared by changing the addition amount of ε-PL. Then, GQDs-ε-PL@4-arm PEG-BA/QCS hydrogels (GQDs-ε-PL@Gel) are synthesized through dynamic imine bonds cross-linking. The sol can transform quickly to gel and the gelation time can be controlled by adjusting the specific gravity of the input raw materials to water. FT-IR and thermogravimetric analyses indicate the successful synthesis of GQDs-ε-PL and GQDs-ε-PL@Gel. The microstructure observation reveals that GQDs-ε-PL has a sheet-like structure with an average size of 65 nm, while GQDs-ε-PL@Gel has a porous network structure. Both GQDs-ε-PL and GQDs-ε-PL@Gel have good fluorescence stability, photothermal and cytocompatibility, and display better antibacterial effect against Escherichia coli , Staphylococcus aureus and Pseudomonas aeruginosa through chemical and photothermal synergistic sterilization. More importantly, GQDs-ε-PL@Gel can repeatedly self-heal after being damaged, which is more beneficial to provide an effective wound closure environment for wounds and to be used as wound dressings. Graphical abstract