Near-Infrared Laser-Excited Nanoparticles To Eradicate Multidrug-Resistant Bacteria and Promote Wound Healing

With the ever-growing threat of bacterial infections, especially for multidrug-resistant microbial infections, the development of highly effective treatment modalities to inhibit the infections is challenging. Although silver nanoparticles have been intensively applied as antimicrobial agent for decades, the therapeutic efficacy toward multidrug-resistant bacteria is still unsatisfactory. Here, we show that near-infrared (NIR) laser-excited silver triangular nanoparticles (Tri-Ag) can efficiently kill Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus both in vitro and in vivo. Notably, multidrug-resistant bacterial clinical isolates, including methicillin-resistant S. aureus and extended spectrum beta-lactamase E. coli strain were significantly inhibited by the combined treatment of the Tri-Ag with NIR laser irradiation due to their synergistic antibacterial ability. Taking the advantage of its strong near-infrared absorbance, photothermal treatment is also conducted with Tri-Ag, achieving a remarkable synergistic antibacterial effect to inhibit various bacteria at a rather low concentration of this agent. Given the above advantages, the combination therapy of Tri-Ag with assistance of NIR laser may find potential applications to strengthen the antimicrobial arsenal for fighting bacterial infections.