Dados do Trabalho

Título

Biocompatibility, Antibacterial and anti-biofilm effect of ZnO/AgO/TiO2 nanocomposites

Introdução

Nanotechnology enables precise control over size and shape, allowing for the customization of properties optimized for specific applications. Zinc Oxide (ZnO), silver, and Titanium Dioxide (TiO2) possess antimicrobial properties and can be produced using environmentally friendly methods. Combining these materials through nanotechnology can result in new materials with enhanced properties and potentize their biological applications.

Objetivo (s)

Evaluate the antimicrobial and anti-biofilm properties of nanocomposites composed of different proportions of ZnO/Ag and TiO2, as well their biocompatibility. 

Material e Métodos

Nanocomposites were synthesized using a patented method (BR 10 2018 007714 7) with varying proportions of ZnO/Ag and TiO2. The final nanocomposites tested were: ZnO/Ag (9% Ag), TiO2, 25Ti:75ZnAg, 50Ti:50ZnAg, and 75Ti:25ZnAg. The inhibition of bacterial growth was assessed using the broth microdilution method (100 to 6.25 µg/mL) against Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 29213, and a clinical strain of MRSA. Subinhibitory concentrations were selected to evaluate the inhibition of biofilm formation by the bacterial strains by the crystal violet method. Pre-formed biofilms (24 h) were treated with 100 µg/mL – 24h and the cell viability measured by MTT method. To evaluate toxicity against human cells, peripheral blood mononuclear cells (PBMCs) were treated with the same concentration of nanocomposites used in the antibacterial assays. 

Resultados e Conclusão

All tested nanocomposites, except ZnAg at 100 µg/mL, did not exhibit toxicity against PBMCs. The inhibition of bacterial growth indicated that ZnAg demonstrated a higher antibacterial effect (>60%) against S. aureus and MRSA and inhibited their biofilm formation capacity by more than 30%. However, the 75Ti:25ZnAg and 50Ti:50ZnAg nanocomposites showed 50% growth inhibition at 100 µg/mL against these strains. These nanocomposites also exhibited increased antibacterial effects against E. coli (100% inhibition - 50 µg/mL). Additionally, 25Ti:75ZnAg showed action against pre-formed MRSA biofilms, reducing viability by over 35%. The combination of ZnO/Ag/TiO2 maintained antibacterial efficacy while reducing toxicity. Furthermore, the effect against pre-formed biofilms suggests potential clinical applications.

Palavras Chave

nanotechnology; antimicrobial resistance; MRSA; antibiotic.