Nanoparticles make the difference: bacteriocidic, biocompatibility and wound healing merits of laser-transferred...

This study demonstrates the high bactericidal efficiency of silver (Ag) and copper (Cu) nanoparticles synthesized via the laser-induced forward transfer (LIFT) method. The antimicrobial effectiveness of these nanoparticles was confirmed against both Gram positive (S. aureus, L. monocytogenes) and Gram negative (P. aeruginosa, E. coli) bacterial biofilms in vitro (silica glass and CaF₂ substrates), ex vivo (pig skin), and in vivo (mouse wounds). The LIFT method achieved minimal inhibitory and bactericidal concentrations (MIC and MBC) within the lower range of bibliographic data, attributed to the uniform 2D-like surface coverage and chemically clean nature of the nanoparticles. Furthermore, biocompatibility studies revealed low cytotoxicity of LIFT-generated Ag and Cu nanoparticles in human embryonic kidney (HEK293) cells. In vivo experiments on Balb/c mice demonstrated accelerated wound epithelialization without adverse inflammatory or allergic responses for NP-treated wounds compared to the untreated (control). Exposure to AgNPs and CuNPs did not affect the functional/behavioral status of mice. Future research will extend these findings by testing additional animal models and exploring multi-elemental nanoparticles to further elucidate the bactericidal mechanisms. This method can be implemented on the basis of portable laser systems for antibacterial treatment in the field.