Efficient bioactive delivery of aerosolized drugs to human pulmonary epithelial cells cultured in air-liquid interface conditions.
In inhalation therapy, drugs are deposited as aerosols onto the air-facing lung epithelium. The currently used in vitro cell assays for drug testing, however, typically dissolve drugs in the medium, completely covering the cells, which represents an unphysiological drug application scenario. Although physiologically realistic in vitro cell culture models of the pulmonary air-blood barrier are available, reliable, easy-to-handle, and efficient technologies for direct aerosol-to-cell delivery are lacking. Here, we introduce the Air-Liquid Interface (ALI) Cell Exposure-Cloud (ALICE-CLOUD) technology, which uses principles of cloud motion for fast and quantitative delivery of aerosolized liquid drugs to pulmonary cells cultured under realistic ALI conditions. Aerosol-to-cell delivery proved to be highly efficient, reproducible, and rapid when using aerosolized fluorescein as surrogate drug. As a proof-of-concept study for the ALICE-CLOUD, we performed functional efficacy studies with the U.S. Food and Drug Administration-approved proteasome inhibitor, Bortezomib, a novel candidate drug for inhalation therapy. Aerosolized Bortezomib had a pronounced anti-inflammatory effect on human epithelial lung cells (A549), as indicated by a significant reduction of (TNFα-induced) IL-8 promoter activation. Importantly, cell-based therapeutic efficacy of aerosolized Bortezomib under ALI conditions was similar to that under dissolved and nonaerosolized submerged conditions, but with faster uptake kinetics. Our data indicate that the ALICE-CLOUD is a reliable tool for aerosolized drug screening with cells cultured under ALI conditions, which combines ease of handling with rapid, efficient, and dosimetrically accurate drug-to-cell delivery. This may pave the way for screening of inhalable drugs under physiologically more relevant and, hence, potentially more predictive conditions than the currently used submerged cell culture systems.
1 Comprehensive Pneumology Center, Member of the German Center for Lung Research, Munich, Germany.
Anke-Gabriele
AG
Lenz
Tobias
T
Stoeger
Daniele
D
Cei
Martina
M
Schmidmeir
Nora
N
Semren
Gerald
G
Burgstaller
Bernd
B
Lentner
Oliver
O
Eickelberg
Silke
S
Meiners
Otmar
O
Schmid
D000280:Administration, Inhalation; D000336:Aerosols; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage* / Q000378:metabolism; D015824:Blood-Air Barrier / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D001897:Boronic Acids / Q000008:administration & dosage* / Q000378:metabolism; D000069286:Bortezomib; D018929:Cell Culture Techniques; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D006801:Humans; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D011401:Promoter Regions, Genetic; D061988:Proteasome Inhibitors / Q000008:administration & dosage* / Q000378:metabolism; D011719:Pyrazines / Q000008:administration & dosage* / Q000378:metabolism; D015203:Reproducibility of Results; D020545:Respiratory Mucosa / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D015533:Transcriptional Activation / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D015854:Up-Regulation
D000336:Aerosols; D000893:Anti-Inflammatory Agents; D001897:Boronic Acids; C508606:CXCL8 protein, human; D016209:Interleukin-8; D061988:Proteasome Inhibitors; D011719:Pyrazines; D014409:Tumor Necrosis Factor-alpha; D000069286:Bortezomib
aerosolized drug delivery; comparison of air–liquid interface and submerged cell culture; inflammation; lung epithelial cell; proteasome inhibitor