Zinc-Based Nanoparticles Reduce Bacterial Biofilm Formation

Rafael Bianchini Fulindi; Juliana Domingues Rodrigues; Thulio Wliandon Lemos Barbosa; Ariana D Goncalves Garcia; Felipe de Almeida La Porta; Sebastião Pratavieira; Leila Aparecida Chiavacci; João Pessoa Araújo Junior; Paulo Inácio da Costa; Luis R Martinez

doi:10.1128/spectrum.04831-22

Zinc-Based Nanoparticles Reduce Bacterial Biofilm Formation

Microbiol Spectr. 2023 Feb 28;11(2):e0483122. doi: 10.1128/spectrum.04831-22. Online ahead of print.

Affiliations

¹ Departments of Clinical Analysis, São Paulo State University (UNESP), Araraquara, São Paulo, Brazil.
² Departments of Drugs and Medicines, School of Pharmaceutical Sciences, São Paulo State University (UNESP), Araraquara, São Paulo, Brazil.
³ Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, USA.
⁴ Department of Chemistry, Federal Technological University of Paraná (UTFPR), Londrina, Paraná, Brazil.
⁵ São Carlos Physics Department, University of São Paulo, São Carlos, São Paulo, Brazil.
⁶ Biotechnology Institute, São Paulo State University, Botucatu, São Paulo, Brazil.
⁷ Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA.
⁸ Center for Immunology and Transplantation, University of Florida, Gainesville, Florida, USA.
⁹ Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, Florida, USA.

Abstract

Biofilm formation is important for microbial survival in hostile environments and a phenotype that provides microorganisms with antimicrobial resistance. Zinc oxide (ZnO) and Zinc sulfide (ZnS) nanoparticles (NPs) present potential antimicrobial properties for biomedical and food industry applications. Here, we aimed to analyze, for the first time, the bactericidal and antibiofilm activity of ZnS NPs against Staphylococcus aureus, Klebsiella oxytoca, and Pseudomonas aeruginosa, all medically important bacteria in developed countries. We compared ZnS NPs antimicrobial activity to ZnO NPs, which have been extensively studied. Using the colorimetric XTT reduction assay to observe the metabolic activity of bacterial cells and the crystal violet assay to measure biofilm mass, we demonstrated that ZnS and ZnO had similar efficacy in killing planktonic bacterial cells and reducing biofilm formation, with S. aureus being more susceptible to both therapeutics than K. oxytoca and P. aeruginosa. Crystal violet staining and confocal microscopy validated that Zn NPs inhibit biofilm formation and cause architectural damage. Our findings provide proof of principle that ZnS NPs have antibiofilm activity, and can be potentially used in medical and food industry applications, such as treatment of wound infections or package coating for food preservation. IMPORTANCE Zinc (Zn)-based nanoparticles (NPs) can be potentially used in medical and food preservation applications. As proof of principle, we investigated the bactericidal and antibiofilm activity of zinc oxide (ZnO) and zinc sulfide (ZnS) NPs against medically important bacteria. Zn-based NPs were similarly effective in killing planktonic and biofilm-associated Staphylococcus aureus, Klebsiella oxytoca, and Pseudomonas aeruginosa cells. However, S. aureus was more susceptible to these investigational therapeutics. Although further studies are warranted, our findings suggest the possibility of future use of Zn-based NPs in the treatment of skin infections or preservation of food.

Keywords: antimicrobial activity; bacteria; biofilms; nanoparticles; zinc oxide; zinc sulfide.

Grants and funding

R01 AI145559/AI/NIAID NIH HHS/United States