RT Journal Article T1 Histological Assessment of Respiratory Tract and Liver of BALB/c Mice Nebulized with Tocilizumab A1 Andrés Gamazo, Paloma Jimena de A1 Ferreiro, Sergio A1 Flores, Ángela A1 García, Almudena A1 Henriquez-Camacho, César AB Pulmonary drug delivery offers a minimally invasive and efficient method for treating lung conditions, leveraging the lungs’ extensive surface area and blood flow for rapid drug absorption. Nebulized therapies aim to deliver drugs directly to the lung tissue. This study investigates the histological impact of nebulized tocilizumab—a monoclonal antibody targeting IL-6, traditionally administered intravenously for rheumatoid arthritis and severe COVID-19—on a murine model. Thirty BALB/c mice were nebulized with tocilizumab (10 mg, 5 mg, and 2.5 mg) and six controls were nebulized with saline solution. They were euthanized 48 h later, and their organs (lungs, nasal mucosa, and liver) were analyzed by a microscopic histological evaluation. The results indicate that all the mice survived the 48 h post-nebulization period without systemic compromise. The macroscopic examination showed no abnormalities, and the histopathological analysis revealed greater lung vascular changes in the control group than in the nebulized animals, which is attributable to the euthanasia with carbon dioxide. Additionally, increased alveolar macrophages were observed in the nebulized groups compared to controls. No significant histological changes were observed in the liver, indicating the safety of nebulized tocilizumab. In conclusion, these findings suggest the potential of nebulized tocilizumab for treating pulmonary inflammation, warranting further research to establish its efficacy and safety in clinical settings. PB MDPI YR 2024 FD 2024-06-27 LK https://hdl.handle.net/20.500.14352/107693 UL https://hdl.handle.net/20.500.14352/107693 LA eng NO de Andres, P.J.; Ferreiro, S.; Flores, A.; Garcia, A.; Henriquez- Camacho, C. Histological Assessment of Respiratory Tract and Liver of BALB/c Mice Nebulized with Tocilizumab. Pharmaceutics 2024, 16, 862. https://doi.org/10.3390/ pharmaceutics16070862 NO Instituto de Investigación Sanitaria Fundación Jiménez Díaz NO Hospital Rey Juan Carlos NO ROCHE Farma DS Docta Complutense RD 13 abr 2025