Thymus vulgaris essential oil + tobramycin within nanostructured archaeolipid carriers: a new approach against Pseudomonas aeruginosa biofilms

PEREZ, NOELIA; ALTUBE, MARIA JULIA; RAMOS SOUZA BARBOSA, LEANDRO; ROMERO, EDER LILIA; PEREZ, ANA PAULA

PHYTOMEDICINE

ELSEVIER GMBH

Año: 2022

0944-7113

Pseudomonas aeruginosa biofilms in the respiratory tract of patients with an excessiveinflammatory context are difficult to eradicate. New medicines that simultaneously targetbiofilms and inflammation should be developed.Co-delivery of Thymus vulgaris essential oil (EOT) and tobramycin (TB) by nanostructuredarchaeolipids carriers (NAC) could support nebulization as well as improve EOT and TBantioxidant, anti-inflammatory and antibiofilm activity.NAC were prepared by loading EOT and TB in NAC having a compritol and miglyolcore, covered with a shell of archaeolipids, extracted from the hyperhalophylic archaebacteriaHalorubrum tebenquichense, and Tween 80. NAC were structurally characterized,including DSC thermograms, Raman spectra, TB release profile, EOT volatilization and invitro antioxidant activity. In addition, stability upon nebulization, autoclaving and storagewere assessed. The antibiofilm activity on P. aeruginosa PAO1 established biofilm of NAC and the cytotoxicity on human lung epithelial cells and macrophage weredetermined, as well as intracellular reactive oxygen species (ROS) production and cytokinesrelease on LPS stimulated cells.NAC showed a size of 197 ± 16 nm with PdI of 0.3 ± 0.1 and ζ Potential of -38 ± 3 mV.Structural characterization suggested that EOT was trapped in the compritol-miglyol core andTB was distributed between the surface of nanoparticles and free in solution. NACdisplayed a dual release profile of TB, a delayed release of EOT and improved EOTs in vitroantioxidant activity. While NAC preserved its structural features after nebulization,autoclaving and 18 months of storage, carriers without archaeolipids gelled at roomtemperature and showed a significant increase of size after the same storage time. Belowcytotoxic concentration, NAC decreased bacteria viability and enhanced the disruptionof established PAO1 biofilms compared to free TB and EOT. Also, the strong entrapment ofEOT in NAC delayed its volatilization, decreased intracellular ROS production andmaintained its anti-inflammatory activity in LPS stimulated cells.Combination of EOT +TB within NAC result in a stable and nebulizable formulationthat enhanced the antioxidant and anti-biofilm activity of free ingredients, improved theirability to decreased intracellular ROS and provided anti-inflammatory activity, at noncytotoxic concentrations on eukaryotic cells.