Facile suspension flame spray fabrication of polylactic acid-povidone-iodine coatings for antimicrobial applications

[Display omitted] •Polylactic acid-povidone-iodine composite coatings were deposited by flame spray.•Coatings showed uniform structure, smooth topography and well retained chemistry.•Homogeneous entrapment of nanosized povidone-iodine was obtained in the coating.•The composite coating showed over 99.99 % antibacterial rate. A facile suspension flame deposition route for fabricating polylactic acid (PLA)-based antimicrobial coatings has been developed in this work. Mixture of povidone-iodine (PVP-I) solution and PLA particles was prepared as the starting feedstock to make the PLA-PVP-I composite coatings. Successful fabrication of the PLA-PVP-I coatings were confirmed by microstructure and chemistry analyses. The coatings showed a homogenous structure and smooth topographical features with no visible pores. Well retained chemistry of PLA and uniform dispersion of PVP-I was revealed in the coatings. Antibacterial testing showed remarkable antimicrobial activity of the PLA-PVP-I coatings against both Escherichia coli and Staphylococcus aureus with a bactericidal rate over 99.99 %, which is likely attributed to the rapid release of iodine. This study provides a promising substrate-independent thermal spray route for constructing antimicrobial coatings for potential biomedical applications.