Photocatalytic effect of N-TiO2 conjugated with folic acid against biofilm-forming resistant bacteria

Raphaella I S Oliveira; Iracema N de Oliveira; Juliana F de Conto; Augusto M de Souza; Silvia R Batistuzzo de Medeiros; Silvia M Egues; Francine F Padilha; Maria L Hernández-Macedo

doi:10.1016/j.heliyon.2023.e22108

Photocatalytic effect of N-TiO₂ conjugated with folic acid against biofilm-forming resistant bacteria

Heliyon. 2023 Nov 7;9(11):e22108. doi: 10.1016/j.heliyon.2023.e22108. eCollection 2023 Nov.

Authors

Affiliations

¹ Graduate Program in Industrial Biotechnology, Tiradentes University, 49032-490, Aracaju, SE, Brazil.
² Laboratory of Molecular Biology, Institute of Technology and Research, Tiradentes University, Aracaju, SE, Brazil.
³ Laboratory of Materials Synthesis and Chromatography, Center for Studies in Colloidal Systems, Institute of Technology and Research, Tiradentes University, Aracaju, SE, Brazil.
⁴ Department of Cell Biology and Genetics, Bioscience Center, Federal University of Rio Grande do Norte, 59078-900, Natal, RN, Brazil.
⁵ Graduate Program in Process Engineering, Tiradentes University, 49037-580 Aracaju, SE, Brazil.
⁶ Biomaterials Laboratory, Technology and Research Institute, Tiradentes University, Aracaju, Sergipe, Brazil.

Abstract

Antibiotic resistance challenges the treatment of bacterial biofilm-related infections, but the use of nanoparticles as a treatment is a promising strategy to overcome bacterial infections. This study applied nitrogen-doped titanium dioxide (N-TiO₂) conjugated with folic acid (FA) on biofilm-forming resistant bacteria. The photocatalytic effect of TiO₂ nanoparticles (NPs) was studied under ultraviolet (UV), visible light, and dark conditions at 60, 120, and 180 min against planktonic cells and biofilms of Staphylococcus aureus, methicillin-resistant Staphylococcus aureus (MRSA), and Pseudomonas aeruginosa. TiO₂ NPs were in the anatase phase, spherical shaped with sizes of 10-13 nm, and effectively doped and conjugated with N and FA. The FA-conjugated nanoparticles (N-TiO₂-FA and FA-TiO₂) were shown to have a bactericidal effect on all bacteria between 60 and 180 min under UV and visible light conditions. Concerning biofilms, N-TiO₂-FA was shown to have a highly disruptive effect on all bacterial biofilms under UV irradiation at 180 min. Meanwhile, the nanoparticles did not show DNA damaging potential and they had no cytostatic effect, indicating that these NPs are biocompatible. In sum, nanoparticle conjugation with FA promoted photocatalytic effectiveness, revealing the promise this nanomaterial holds as a biocompatible antimicrobial agent.

Keywords: Bacterial biofilm; Folic acid; Photocatalysis; Resistant bacteria; TiO2.