Fabrication of polylactide composites with silver nanoparticles by sputtering deposition and their antimicrobial and antiviral applications

Silver-containing composites formed by sputtering deposition on the surface of polylactide (PLA) films have been developed; they contain a layer of silver nanoparticles of different thicknesses depending on the deposition time, namely 1, 3 and 5 min. It was found that with a deposition time of 5 min a layer with a thickness of ca 100 nm is formed. The average size of the Ag nanoparticles is 5.9 nm, and the average specific surface area S_sp is 97 m² g⁻¹. The samples obtained were characterized by wide-angle X-ray scattering, TEM, TGA and DSC and their antimicrobial, antiviral and cytotoxic properties were studied as well. It was found that the thinnest layer of silver (deposited for 1 min) has the greatest effect on the PLA's heat resistance and glass transition temperature. PLA-Ag composites formed by silver sputtering deposition show antimicrobial activity against the studied test cultures of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa, and the activity of the samples increases with increasing duration of silver deposition. PLA-Ag composites formed by silver deposition for 5 min had a weak virucidal effect against herpes simplex virus type 1 and influenza virus type A. Irrespective of the sputtering time of silver the composites obtained were not cytotoxic; at a dilution of 1:10 and more they did not significantly inhibit the viability of MDCK, BHK and Hep-2 cells. © 2025 Society of Chemical Industry.