Wound healing acceleration by antibacterial biodegradable black phosphorus nanosheets loaded with cationic carbon dots

Microorganism invasion is still a severe threat for wound healing, which usually induces severe complications and cannot be eradicated completely. Thus, a biodegradable nanomaterial for guarding against bacteria-associated wound infection and accelerating wound healing is of vital importance. Here, black phosphorus nanosheets (BPs) were successfully decorated with cationic carbon dots (CDs) through an in situ growth strategy. The BPs@CDs exhibit photonresponsiveness and contact-responsiveness as an antibacterial agent, which shorten wound healing time. Moreover, the BPs@CDs show available photothermal and photodynamic therapy via exploring their photothermal properties and the ability of singlet-oxygen (O-1(2)) production. Astonishingly, the BPs@CDs could possess antibacterial activity even without laser illumination due to an electrostatic attraction between bacteria and cationic CDs on the surface of BPs. This chemical therapy causes the antibacterial process to occur more accurately and for a faster O-1(2) release to kill bacteria than in a normal process. Importantly, BPs@CDs display outstanding cytocompatibility and hemocompatibility. In vitro and in vivo investigations demonstrate that the BPs@CDs have enhanced antibacterial effect and can significantly accelerate skin tissue regeneration and wound closure. Given their antibacterial triplecombination therapy and excellent physicochemical properties, the broad application of BPs@CDs in bacteria-associated wound management is anticipated. [GRAPHICS] .

Automated summary

This study developed a biodegradable nanomaterial for preventing bacteria-associated wound infections and accelerating wound healing, showing photon responsiveness and contact-responsiveness as an antibacterial agent. The material also exhibited photothermal and photodynamic therapy capabilities, and possessed antibacterial activity even without laser illumination due to an electrostatic attraction between bacteria and cationic CDs on its surface.