Surface Modification of Nanocrystalline TiO2 Materials with Sulfonated Porphyrins for Visible Light Antimicrobial Therapy

• Published in: Catalysts 2019-10, Vol.9 (10), p.821
• Main Authors: Sułek, Adam, Pucelik, Barbara, Kobielusz, Marcin, Łabuz, Przemysław, Dubin, Grzegorz, Dąbrowski, Janusz M.
• Format: Article
• Language: English
• Subjects: Anatase; Antibiotics; Antiinfectives and antibacterials; antimicrobial activity; Antimicrobial agents; Bacteria; Bacterial infections; Biofilms; Biomedical materials; Catalysts; Chemical reactions; Deactivation; E coli; Fluorescence; Gram-negative bacteria; Gram-positive bacteria; Hydrogen peroxide; Light; Light irradiation; Metal oxides; Metallography; Microorganisms; Morphology; Nanomaterials; Nanoparticles; Optical properties; Permeability; Photocatalysis; photocatalysts; photodynamic inactivation of microorganisms (pdi); Photon correlation spectroscopy; photosensitization; Porphyrins; Scanning electron microscopy; Size distribution; tio2; Titanium dioxide
• ISSN: 2073-4344; 2073-4344
• DOI: 10.3390/catal9100821

Highly-active, surface-modified anatase TiO2 nanoparticles were successfully synthesized and characterized. The morphological and optical properties of the obtained (metallo)porphyrin@qTiO2 materials were evaluated using absorption and fluorescence spectroscopy, scanning electron microscopy (SEM) imaging, and dynamic light scattering (DLS). These hybrid nanoparticles efficiently generated reactive oxygen species (ROS) under blue-light irradiation (420 ± 20 nm) and possessed a unimodal size distribution of 20–70 nm in diameter. The antimicrobial performance of the synthetized agents was examined against Gram-negative and Gram-positive bacteria. After a short-term incubation of microorganisms with nanomaterials (at 1 g/L) and irradiation with blue-light at a dose of 10 J/cm2, 2–3 logs of Escherichia coli, and 3–4 logs of Staphylococcus aureus were inactivated. A further decrease in bacteria viability was observed after potentiation photodynamic inactivation (PDI), either by H2O2 or KI, resulting in complete microorganism eradication even when using low material concentration (from 0.1 g/L). SEM analysis of bacteria morphology after each mode of PDI suggested different mechanisms of cellular disruption depending on the type of generated oxygen and/or iodide species. These data suggest that TiO2-based materials modified with sulfonated porphyrins are efficient photocatalysts that could be successfully used in biomedical strategies, most notably, photodynamic inactivation of microorganisms.