1. The activity of a Ga(III) catecholate complex against Aspergillus fumigatus in conditions mimicking cystic fibrosis lung and inhaled formulations for its pulmonary administration.
- Author
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Grassiri B, Esin S, Piatek ME, More O'Ferrall L, Sake JA, Griffith DM, Kavanagh K, Ehrhardt C, Maria Piras A, Batoni G, and Marie Healy A
- Subjects
- Administration, Inhalation, Humans, Particle Size, Lung drug effects, Catechols chemistry, Catechols administration & dosage, Powders, Nebulizers and Vaporizers, Dry Powder Inhalers, Microbial Sensitivity Tests, Aspergillus fumigatus drug effects, Cystic Fibrosis drug therapy, Antifungal Agents administration & dosage, Antifungal Agents chemistry, Antifungal Agents pharmacology, Gallium administration & dosage, Gallium chemistry
- Abstract
Azole-resistant Aspergillus fumigatus (A. fumigatus) is an emerging worldwide pathogen. Pulmonary aspergillosis primarily affects severely immunocompromised patients and is also a particularly critical condition for cystic fibrosis (CF) patients. A recently designed gallium polypyridyl catecholate complex, GaS1, has previously demonstrated in vitro and in vivo antimicrobial activity against Gram-negative bacteria. In the present work GaS1 activity was assessed against A. fumigatus clinical isolates in a novel air-liquid-interface lung infection model, mimicking the conditions found in the CF airways. Furthermore, in this study both a solution for nebulisation and dry powders for inhalation were developed with a view to optimising GaS1 delivery to the lung. The solution for nebulisation was characterised for its osmolality and pH, while the dry powders were characterised by scanning electron microscopy, powder X-ray diffraction, thermal analysis and laser light scattering particle size analysis. The aerodynamic deposition profiles of all formulations were determined using a next generation impactor. GaS1, tested in a concentration range of 0.016-0.5 mg/mL, inhibited the growth of A. fumigatus lung isolates in a complex host-environment-mimicking medium at the non-toxic concentration of 0.063 mg/mL. A marked dose-dependent antifungal activity of GaS1 was also observed in the presence of differentiated human distal lung epithelial cells (NCI-H441) at the air liquid interface, with nearly no fungal growth detected at the macroscopic and microscopic level. A solution for nebulisation and three different dry powder inhaler formulations, prepared by spray-drying GaS1 with different concentrations of L-leucine, displayed suitable aerodynamic characteristics for GaS1 delivery to the lungs, while maintaining excellent antifungal activity. Overall, the results obtained highlight the potential of gallium-polypyridyl catecholate complexes for the management of difficult-to-treat A. fumigatus pulmonary infections., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2024
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