Germanene-modified chitosan hydrogel for treating bacterial wound infection: An ingenious hydrogel-assisted photothermal therapy strategy

The elaborate design of an ingenious hydrogel-assisted photothermal therapy (PTT) platform is a promising strategy for treating bacterial wound infections. Herein, a new generation of germanene nanocrystals (Ge NCs) with excellent photothermal performance are prepared via an ice-bath sonication liquid-phase exfoliation technique. Whereafter, by crosslinking interaction between chitosan and zinc acetate, as well as self-assembly property between Ge NCs and chitosan, we successfully construct an innovative germanene-modified chitosan antimicrobial hydrogel (CS/Ge NCs0.8) integrating capture and killing bacteria performances. When co-cultured with bacteria, CS/Ge NCs0.8 hydrogel with the positive charge can adsorb and restrict bacteria in the range of PTT destruction. Once the near-infrared laser is introduced, CS/Ge NCs0.8 hydrogel will effectively convert light energy into localized heat, further inducing bacterial death. By this entirely novel modality, CS/Ge NCs0.8 hydrogel exhibits marvelous antibacterial property against E. coli and S. aureus in vitro. Furthermore, in vivo studies demonstrate that CS/Ge NCs0.8 hydrogel possesses the ability to significantly rescue S. aureus-induced skin wound infections, suggesting CS/Ge NCs0.8 hydrogel can be served as an antibacterial dressing. Strikingly, this is the first-ever report of CS/Ge NCs0.8 hydrogel in the antibacterial field, which may spur a wave of developing Ge-based biomaterials to benefit biomedical applications.