Design of in vitro lung mucus-microbiota model to assess efficacy of inhaled antibiotics
Mahmoud H. Abu Elella1, Simon Andrews2, Glyn Barrett2, Vitaliy Khutoryanskiy1, Hisham Al-Obaidi1
1School of Pharmacy, University of Reading, Reading, RG6 6UR, UK
2School of Biological Sciences, University of Reading, Reading, RG6 6UR, UK
Summary
Over a few decades, many scientific experiments worldwide consumed huge number of animals for the testing of various inhaled drugs. Among them, several studies require to scarify animals to extract mucosal tissues for examining the action of inhaled powders. Recently, designing alternative methods instead of animal models is an attractive strategy. For instance, some synthetic 3D polymeric hydrogels have similarities to the chemical structure of the mucus that lines-mucosal tissues. Here, we aim to design mucus-mimicking hydrogels, simulating lung-microbiota layer, and adapted a Andersen cascade impactor (ACI) to assess the deposition of aerosolised ciprofloxacin powders. Ciprofloxacin powders were prepared using two and three fluid nozzle spray dryers. Moreover, via free-radical polymerisation technique, hydrogels were synthesised by copolymerising N-acryloyl-glucosamine with 2-hydroxyethylmethacrylate. In our model, we used E. coli, as a bacterial model, to simulate the lung’s mucus-microbiota layer and modified Gamble’s solution with dipalmitoylphosphatidyl choline, and citrate as simulated lung fluid (SLF). The findings revealed successful preparation of highly porous mucosa-mimetic hydrogels via the elucidation of the surface structure with Cryo-SEM techniques. After mixing the hydrogels with SLF, the in vitro mucus-microbiota-ACI model was validated by administering lactose. The deposition results showed minimal differences in deposition between a control and modified ACI, and bacteria were completely eradicated for samples treated with ciprofloxacin, demonstrating the diffusion of deposited ciprofloxacin within porous hydrogel layers.