pH-responsive molybdenum disulphide composite nanomaterials for skin wound healing using “ROS leveraging” synergistic immunomodulation

With the increasing prevalence of drug-resistant bacterial infections, wound bacterial infections have evolved into an escalating medical problem that poses a threat to the individual health as well as global public health. Traditional drug therapy not only suffers from a single treatment method, low drug utilisation and limited therapeutic effect, but long-term antibiotic abuse has significantly increased bacterial resistance. It is imperative to develop an antibiotic-free biomaterial with antibacterial and anti-inflammatory properties. The current use of photothermal therapy (PTT) and photodynamic therapy (PDT) relies on the generation of massive reactive oxygen species (ROS), which inevitably aggravates the inflammatory response. Herein, we developed AuAg bimetallic nanoparticles based on PDA modification and prepared a novel MoS₂-based composite nanomaterials (AuAg@PDA-MoS₂ NPs) with multiple mechanisms of antibacterial and anti-inflammatory potentials through the adhesion of PDA. In the early phase, PDT and PTT generated a large amount of ROS for rapid sterilisation. While in the later stage, MoS₂ mimicked the peroxidase activity to leverage the ROS, balancing the generation of ROS in the infected environment to achieve the long-term anti-inflammatory. <i>In vitro</i> experiments showed that the killing efficiency of AuAg@PDA-MoS₂ NPs was nearly 99 % under the irradiation of 808 nm near-infrared light for 10 min, which demonstrated excellent antibacterial activity. <i>In vivo</i> experiments showed that 808 nm NIR-assisted AuAg@PDA-MoS₂ NPs to effectively inhibit infection, alleviated the inflammation, and accelerated the wound healing process. Therefore, AuAg@PDA-MoS₂ NPs as a novel biomaterial could achieve programmed antimicrobial and anti-inflammatory effects, which has a promising potential for future application in the treatment of infected wounds.