Control of Biofilm and Virulence in <i>Pseudomonas aeruginosa</i> by Green-Synthesized Titanium–Cerium Nanocomposites

Abstract

Antimicrobial resistance (AMR) has become a critical global health challenge. Infections, particularly those caused by multidrug-resistant (MDR) pathogens, rank among the top causes of human mortality worldwide. Pseudomonas aeruginosa occupies a prominent position among pathogens responsible for opportunistic infections in humans. P. aeruginosa stands as a primary cause of chronic respiratory infections, significantly contributing to the burden of these chronic diseases. In the medical domain, nanotechnologies offer significant potential, spanning various applications, including advanced imaging, diagnostic devices, drug delivery systems, implants, tissue-engineered structures, and pharmaceutical treatments. Given the challenges associated with AMR and the limited discovery of new drugs to combat MDR microbes, there is a critical need for alternative strategies to address the problem of AMR. In this study, we synthesized titanium–cerium nanocomposites (Ti–Ce–NCs) using an eco-friendly green synthesis approach. X-ray diffraction (XRD) analysis confirmed the crystalline nature of the Ti–Ce–NCs and determined the particle size to be 17.07 nm. Electron microscopy revealed the size range of the particles to be 13 to 54 nm, where the majority of the particles were in the 20 to 25 nm range. Upon examining the composition, the Ti–Ce–NCs were determined to be composed of cerium, oxygen, and titanium, whose relative abundance were 36.86, 36.6, and 24.77% by weight, respectively. These nanocomposites were then evaluated for their effectiveness against various virulent traits and biofilms in P. aeruginosa. Out of six tested virulence factors, more than 50% inhibition of five virulence factors of P. aeruginosa was found. Roughly 60% inhibition of biofilm was also found in the presence of 400 µg/mL Ti–Ce–NCs. The nanocomposites also altered the biofilm architecture of the test bacterium. The success of this research opens doors for the potential use of such nanomaterials in the discovery of new antibacterial agents to combat drug-resistant bacteria.

Keywords

• nanocomposite
• green synthesis
• biofilm
• quorum sensing
• antimicrobial resistance
• <i>Pseudomonas aeruginosa</i>