Biogenic nanosilver-fabricated endotracheal tube to prevent microbial colonization in a veterinary hospital

Appl Microbiol Biotechnol. 2023 Feb;107(2-3):623-638. doi: 10.1007/s00253-022-12327-w. Epub 2022 Dec 23.

Abstract

COVID-19 patients have often required prolonged endotracheal intubation, increasing the risk of developing ventilator-associated pneumonia (VAP). A preventive strategy is proposed based on an endotracheal tube (ETT) modified by the in situ deposition of eucalyptus-mediated synthesized silver nanoparticles (AgNPs). The surfaces of the modified ETT were embedded with AgNPs of approximately 28 nm and presented a nanoscale roughness. Energy dispersive X-ray spectroscopy confirmed the presence of silver on and inside the coated ETT, which exhibited excellent antimicrobial activity against Gram-positive and Gram-negative bacteria, and fungi, including multidrug-resistant clinical isolates. Inhibition of planktonic growth and microbial adhesion ranged from 99 to 99.999% without cytotoxic effects on mammalian cells. Kinetic studies showed that microbial adhesion to the coated surface was inhibited within 2 h. Cell viability in biofilms supplemented with human tracheal mucus was reduced by up to 95%. In a porcine VAP model, the AgNPs-coated ETT prevented adhesion of Pseudomonas aeruginosa and completely inhibited bacterial invasion of lung tissue. The potential antimicrobial efficacy and safety of the coated ETT were established in a randomized control trial involving 47 veterinary patients. The microbial burden was significantly lower on the surface of the AgNPs-coated ETT than on the uncoated ETT (p < 0.05). KEY POINTS: • Endotracheal tube surfaces were modified by coating with green-synthesized AgNPs • P. aeruginosa burden of endotracheal tube and lung was reduced in a porcine model • Effective antimicrobial activity and safety was demonstrated in a clinical trial.

Keywords: Animal models; Biofilms; COVID-19; Endotracheal tube; Silver nanoparticles; Ventilator-associated pneumonia.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology
  • Anti-Infective Agents* / pharmacology
  • Biofilms
  • COVID-19*
  • Communicable Diseases*
  • Gram-Negative Bacteria
  • Gram-Positive Bacteria
  • Hospitals, Animal
  • Humans
  • Intubation, Intratracheal / methods
  • Kinetics
  • Mammals
  • Metal Nanoparticles* / chemistry
  • Pneumonia, Ventilator-Associated* / microbiology
  • Pneumonia, Ventilator-Associated* / prevention & control
  • Silver / pharmacology
  • Swine

Substances

  • Anti-Bacterial Agents
  • Silver
  • Anti-Infective Agents