Influence of levofloxacin and clarithromycin on the structure of DPPC monolayers

Publication date: Available online 28 May 2019Source: Biochimica et Biophysica Acta (BBA) - BiomembranesAuthor(s): Stephanie Ortiz-Collazos, Paulo H.S. Picciani, Osvaldo N. Oliveira, Andre S. Pimentel, Karen J. EdlerAbstractResearch on lipid/drug interactions at the nanoscale underpins the emergence of synergistic mechanisms for topical drug administration. The structural understanding of bio-mimetic systems employing 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) as a lung surfactant model mixed with antibiotics, as well as their biophysical properties, is of critical importance to modulate the effectiveness of therapeutic agents released directly to the airways. In this paper, we investigate the structural details of the interaction between Levofloxacin, ‘a respiratory quinolone’, and the macrolide Clarithromycin, with DPPC monolayers at the air-water interface, using a combination of Brewster angle microscopy, polarization modulation-infrared reflection-adsorption spectroscopy (PM-IRRAS), surface pressure isotherms and neutron reflectometry (NR) to describe the structural details of this interaction. The results allowed association of changes in the π-A isotherm profile with changes in the molecular organization and the co-localization of the antibiotics within the lipid monolayer by NR measurements. Overall, both antibiotics are able to increase the thickness of the acyl tails in DPPC monolayers with a corresponding reduction in tail tilt as well as to interact w...
Source: Biochimica et Biophysica Acta (BBA) Biomembranes - Category: Biochemistry Source Type: research