Background: Titanium dioxide nanoparticles (TiO 2 NPs) have a wide range of applications in several industrial and biomedical domains. Based on the evidence, the workers exposed to inhaled nanosized TiO 2 powder are more susceptible to the risks of developing respiratory diseases. Accordingly, this issue has increasingly attracted the researchers' interest in understanding the consequences of TiO 2 NPs exposure. Regarding this, the present study was conducted to analyze the local effects of TiO 2 NPs on allergic airway inflammation and their uptake in a mouse model of ovalbumin (OVA)-induced allergic airway inflammation. Methods: For the purpose of the study, female BALB/c mice with or without asthma were intranasally administered with TiO 2 NPs. The mice were subjected to histological assessment, lung function testing, scanning electron microscopy (SEM), inductively coupled plasma mass spectrometry (ICP-MS), and NP uptake measurement. In addition, T helper (Th) 1/Th2 cytokines were evaluated in the lung homogenate using the enzyme-linked immunosorbent assay. Results: According to the results, the mice receiving OVA alone or OVA plus TiO 2 NPs showed eosinophilic infiltrates and mucus overproduction in the lung tissues, compared to the controls. Furthermore, a significant elevation was observed in the circulating Th2 cytokines, including interleukin (IL)-4, IL-5, and IL-13 after NP exposure. The TiO 2 NPs were taken up by alveolar macrophages at different time points. As the results of the SEM and ICP-MS indicated, TiO 2 NPs were present in most of the organs in both asthmatic and non-asthmatic mice.

Interleukin 23 and the interleukin 23 receptor (IL-23-IL23R) are described as the major enhancing factors for Interleukin 17 (IL-17) in allergic airway inflammation. IL-17 is considered to induce neutrophilic inflammation in the lung, which is often observed in severe, steroid-resistant asthma-phenotypes. For that reason, understanding of IL-23 and IL-17 axis is very important for future therapy strategies, targeting neutrophil pathway of bronchial asthma.This study aimed to investigate the distribution and expression of IL-23R under physiological and inflammatory conditions. Therefore, a house dust mite (HDM) model of allergic airway inflammation was performed by treating mice with HDM intranasally. Immunofluorescence staining with panel of antibodies was performed in lung tissues to examine the macrophage, dendritic cell, and T cell subpopulations. The allergic airway inflammation was quantified by histopathological analysis, ELISA measurements, and airway function.HDM-treated mice exhibited a significant allergic airway inflammation including higher amounts of NE+ cells in lung parenchyma. We found only a small amount of IL-23R positives, out of total CD3+T cells, and no upregulation in HDM-treated animals. In contrast, the populations of F4/80+ macrophages and CD11c+F4/80− dendritic cells (DCs) with IL-23R expression were found to be higher. But HDM treatment leads to a significant increase of IL-23R+ macrophages, only. IL-23R was expressed by every examined macrophage subpopulation, whereas only Mϕ1 and hybrids between Mϕ1 and Mϕ2 phenotype and not Mϕ2 were found to upregulate IL-23R. Co-localization of IL-23R and IL-17 was only observed in F4/80+ macrophages, suggesting F4/80+ macrophages express IL-23R along with IL-17 in lung tissue.The study revealed that macrophages involving the IL-23 and IL-17 pathway may provide a potential interesting therapeutic target in neutrophilic bronchial asthma.

Interhospital transport of acute respiratory distress syndrome (ARDS) patients bears transport-associated risks. It is unknown how interhospital extracorporeal membrane oxygenation (ECMO) transfer of COVID-19 patients by mobile ECMO units affects ARDS mortality. We compared the outcome of 94 COVID-19 patients cannulated in primary care hospitals and retrieved by mobile ECMO-teams to that of 84 patients cannulated at five German ECMO centers. Patients were recruited from March 2020 to November 2021. Twentysix transports were airborne, 68 were land-based. Age, sex, body-mass-index, Simplified Acute Physiology Score (SAPS) II, days invasively ventilated, and P/F-Ratio before ECMO initiation were similar in both groups. Counting only regional transports (≤250 km), mean transport distance was 139.5 km ± 17.7 km for helicopter (duration 52.5 ± 10.6 minutes) and 69.8 km ± 44.1 km for ambulance or mobile intensive care unit (duration 57.6 ± 29.4 minutes). Overall time of vvECMO support (20.4 ± 15.2 ECMO days for transported patients vs. 21.0 ± 20.5 for control, p = 0.83) and days invasively ventilated (27.9 ± 18.1 days vs. 32.6 ± 25.1 days, p = 0.16) were similar. Overall mortality did not differ between transported patients and controls (57/94 [61%] vs. 51/83 [61%], p = 0.43). COVID-19 patients cannulated and retrieved by mobile ECMO-teams have no excess risk compared with patients receiving vvECMO at experienced ECMO centers. Patients with COVID-19-associated ARDS, limited comorbidities, and no contraindication for ECMO should be referred early to local ECMO centers.

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