A comparative study on titanium dioxide sol-gel treatment for protein fabrics, focusing on UV transmittance effects

Most of the infections caused by multi-drug resistant (MDR) P. aeruginosa strains are extremely difficult to be treated with conventional antibiotics. Biofilm formation and efflux pumps are recognized as the major antibiotic resistance mechanisms in MDR P. aeruginosa. Biofilm formation by P. aeruginosa depends mainly on the cell-to-cell communication quorum-sensing (QS) systems. Titanium dioxide nanoparticles (TDN) have been used as antimicrobial agents against several microorganisms but have not been reported as an anti-QS agent. This study aims to evaluate the impact of titanium dioxide nanoparticles (TDN) on QS and efflux pump genes expression in MDR P. aeruginosa isolates. The antimicrobial susceptibility of 25 P. aeruginosa isolates were performed by Kirby–Bauer disc diffusion. Titanium dioxide nanoparticles (TDN) were prepared by the sol gel method and characterized by different techniques (DLS, HR-TEM, XRD, and FTIR). The expression of efflux pumps in the MDR isolates was detected by the determination of MICs of different antibiotics in the presence and absence of carbonyl cyanide m-chlorophenylhydrazone (CCCP). Biofilm formation and the antibiofilm activity of TDN were determined using the tissue culture plate method. The effects of TDN on the expression of QS genes and efflux pump genes were tested using real-time polymerase chain reaction (RT-PCR). The average size of the TDNs was 64.77 nm. It was found that TDN showed a significant reduction in biofilm formation (96%) and represented superior antibacterial activity against P. aeruginosa strains in comparison to titanium dioxide powder. In addition, the use of TDN alone or in combination with antibiotics resulted in significant downregulation of the efflux pump genes (MexY, MexB, MexA) and QS-regulated genes (lasR, lasI, rhll, rhlR, pqsA, pqsR) in comparison to the untreated isolate. TDN can increase the therapeutic efficacy of traditional antibiotics by affecting efflux pump expression and quorum-sensing genes controlling biofilm production.

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A comparative study on the efficacy of different probes to predict the photo-activity of nano-titanium dioxide toward biomolecules

RSC Advances ◽

10.1039/c5ra14303a ◽

2015 ◽

Vol 5 (109) ◽

pp. 89559-89568 ◽

Cited By ~ 3

Author(s):

A. Marucco ◽

E. Carella ◽

I. Fenoglio

Keyword(s):

Titanium Dioxide ◽

Comparative Study ◽

Systematic Study ◽

Living Organisms ◽

Nano Titanium Dioxide

A systematic study has been performed to select cell-free tests able to predict the photo-activity of nano-TiO2 in living organisms.

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Photocatalytic Activity Enhancement of Low-pressure Cold-Sprayed TiO2 Coatings Induced by Long-term Water Vapor Exposure

Journal of Thermal Spray Technology ◽

10.1007/s11666-021-01244-5 ◽

2021 ◽

Cited By ~ 1

Author(s):

Seremak Wioletta ◽

Baszczuk Agnieszka ◽

Jasiorski Marek ◽

Gibas Anna ◽

Winnicki Marcin

Keyword(s):

Titanium Dioxide ◽

Photocatalytic Activity ◽

Water Vapor ◽

Sol Gel ◽

Low Pressure ◽

Oxygen Depletion ◽

Amorphous Structure ◽

Industrial Applications ◽

Additional Parameter

AbstractThis work shows that the titanium dioxide coatings obtained by low-pressure cold gas spraying with the use of the sol–gel amorphous TiO2 powder are characterized by photocatalytic activity despite their partial amorphous content. Moreover, the research outcome suggests that the decomposition rate of organic pollutants is enhanced after long-term exposure to moisture. The condensation humidity test is not detrimental to the continuity and integrity of the coating, but the phase composition of coatings changes—with the exposure to water vapor, the portion of the amorphous phase crystallizes into brookite. The mechanism responsible for the conversion of amorphous TiO2 into brookite is attributed to the water-driven dissolution and reprecipitation of TiO6 octahedra. It has been shown that an additional parameter necessary for the stabilization of the brookite is the oxygen depletion of the amorphous structure of titanium dioxide. Considering the results presented in this paper and the advantages of a portable, low-pressure cold spray system for industrial applications, it is expected that TiO2 coatings produced from a sol–gel feedstock powder can be further developed and tested as efficient photocatalysts.

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