Influence of Cigarette Aerosol in Alpha-Synuclein Oligomerization and Cell Viability in SH-SY5Y: Implications for Parkinson's Disease.

Although cigarette aerosol exposure is associated with various adverse health issues, its impact on Parkinson's disease (PD) remains elusive. Here, we investigated the effect of cigarette aerosol extract (CAE) on SH-SY5Y cells for the first time, both with and without α-synuclein (α-Syn) overexpression. We found that α-Syn aggravates CAE-induced cell death, oxidative stress, and mitochondrial dysfunction. Fluorescence cross-correlation spectroscopy (FCCS) revealed a dual distribution of α-Syn within the cells, with homogeneous regions indicative of monomeric α-Syn and punctated regions, suggesting the formation of oligomers. Moreover, we observed colocalization of α-Syn oligomers with lysosomes along with a reduction in autophagy activity. These findings suggest that α-Syn overexpression exacerbates CAE-induced intracellular cytotoxicity, mitochondrial dysfunction, and autophagy dysregulation, leading to elevated cell mortality. Our findings provide new insights into the pathogenic mechanisms linking exposure to cigarette aerosols with neurodegenerative diseases.

Impact of air humidity on the tenacity of different agents in bioaerosols.

Despite the variety of pathogens that are transmitted via the airborne route, few data are available on factors that influence the tenacity of airborne pathogens. In order to better understand and thus control airborne infections, knowledge of these factors is important. In this study, three agents, S. aureus, G. stearothermophilus spores and the MS2 bacteriophage, were aerosolized at relative humidities (RH) varying between 30% and 70%. Air samples were then analyzed to determine the concentration of the agents. S. aureus was found to have significantly lower survival rate in the aerosol at RH above 60%. It showed the lowest recovery rates of the three agents, ranging from 0.13% at approximately 70% RH to 4.39% at 30% RH. G. stearothermophilus spores showed the highest tenacity with recovery rates ranging from 41.85% to 61.73% with little effect of RH. For the MS2 bacteriophage, a significantly lower tenacity in the aerosol was observed with a recovery rate of 4.24% for intermediate RH of approximately 50%. The results of this study confirm the significant influence of the RH on the tenacity of airborne microorganisms depending on the specific agent. These data show that the behavior of microorganism in bioaerosols is varies under different environmental conditions.

A Comparative Study of the Effects of Electronic Cigarette and Traditional Cigarette on the Pulmonary Functions of C57BL/6 Male Mice.

INTRODUCTION: Electronic cigarettes (E-cigs) are in a controversial state. Although E-cig aerosol generally contains fewer harmful substances than smoke from burned traditional cigarettes, aerosol along with other compounds of the E-cigs may also affect lung functions and promote the development of lung-related diseases. We investigated the effects of E-cig on the pulmonary functions of male C57BL/6 mice and reveal the potential underlying mechanisms. METHODS: A total of 60 male C57BL/6 mice were randomly divided into four groups. They were exposed to fresh-air, traditional cigarette smoke, E-cig vapor with 12 mg/mL of nicotine, and E-cig with no nicotine for 8 weeks. Lung functions were evaluated by using quantitative analysis of the whole body plethysmograph, FlexiVent system, lung tissue histological and morphometric analysis, and RT-PCR analysis of mRNA expression of inflammation-related genes. In addition, the effects of nicotine and acrolein on the survival rate and DNA damage were investigated using cultured human alveolar basal epithelial cells. RESULTS: Exposure to E-cig vapor led to significant changes in lung functions and structures including the rupture of the alveolar cavity and enlarged alveolar space. The pathological changes were also accompanied by increased expression of interleukin-6 and tumor necrosis factor-α. CONCLUSIONS: The findings of the present study indicate that the safety of E-cig should be further evaluated. IMPLICATIONS: Some people currently believe that using nicotine-free E-cigs is a safe way to smoke. However, our research shows that E-cigs can cause lung damage regardless of whether they contain nicotine.

CDC Guidelines for the Prevention and Treatment of Anthrax, 2023.

This report updates previous CDC guidelines and recommendations on preferred prevention and treatment regimens regarding naturally occurring anthrax. Also provided are a wide range of alternative regimens to first-line antimicrobial drugs for use if patients have contraindications or intolerances or after a wide-area aerosol release of: Bacillus anthracis spores if resources become limited or a multidrug-resistant B. anthracis strain is used (Hendricks KA, Wright ME, Shadomy SV, et al.; Workgroup on Anthrax Clinical Guidelines. Centers for Disease Control and Prevention expert panel meetings on prevention and treatment of anthrax in adults. Emerg Infect Dis 2014;20:e130687; Meaney-Delman D, Rasmussen SA, Beigi RH, et al. Prophylaxis and treatment of anthrax in pregnant women. Obstet Gynecol 2013;122:885-900; Bradley JS, Peacock G, Krug SE, et al. Pediatric anthrax clinical management. Pediatrics 2014;133:e1411-36). Specifically, this report updates antimicrobial drug and antitoxin use for both postexposure prophylaxis (PEP) and treatment from these previous guidelines best practices and is based on systematic reviews of the literature regarding 1) in vitro antimicrobial drug activity against B. anthracis; 2) in vivo antimicrobial drug efficacy for PEP and treatment; 3) in vivo and human antitoxin efficacy for PEP, treatment, or both; and 4) human survival after antimicrobial drug PEP and treatment of localized anthrax, systemic anthrax, and anthrax meningitis. Changes from previous CDC guidelines and recommendations include an expanded list of alternative antimicrobial drugs to use when first-line antimicrobial drugs are contraindicated or not tolerated or after a bioterrorism event when first-line antimicrobial drugs are depleted or ineffective against a genetically engineered resistant: B. anthracis strain. In addition, these updated guidelines include new recommendations regarding special considerations for the diagnosis and treatment of anthrax meningitis, including comorbid, social, and clinical predictors of anthrax meningitis. The previously published CDC guidelines and recommendations described potentially beneficial critical care measures and clinical assessment tools and procedures for persons with anthrax, which have not changed and are not addressed in this update. In addition, no changes were made to the Advisory Committee on Immunization Practices recommendations for use of anthrax vaccine (Bower WA, Schiffer J, Atmar RL, et al. Use of anthrax vaccine in the United States: recommendations of the Advisory Committee on Immunization Practices, 2019. MMWR Recomm Rep 2019;68[No. RR-4]:1-14). The updated guidelines in this report can be used by health care providers to prevent and treat anthrax and guide emergency preparedness officials and planners as they develop and update plans for a wide-area aerosol release of B. anthracis.

Potentials of a Plasma-Aerosol System for Wound Healing Advanced by Drug Introduction: An In Vitro Study.

Cold plasmas have found their application in a wide range of biomedical fields by virtue of their high chemical reactivity. In the past decades, many attempts have been made to use cold plasmas in wound healing, and within this field, many studies have focused on plasma-induced cell proliferation mechanisms. In this work, one step further has been taken to demonstrate the advanced role of plasma in wound healing. To this end, the simultaneous ability of plasma to induce cell proliferation and permeabilize treated cells has been examined in the current study. The driving force was to advance the wound healing effect of plasma with drug delivery. On this subject, we demonstrate in vitro the healing effect of Ar, Ar+N2 plasma, and their aerosol counterparts. A systematic study has been carried out to study the role of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in cell adhesion, signaling, differentiation, and proliferation. An additional investigation was also performed to study the permeabilization of cells and the delivery of the modeled drug carrier fluorescein isothiocyanate (FITC) labeled dextran into cells upon plasma treatment. Short 35 s plasma treatments were found to promote fibroblast adhesion, migration, signaling, proliferation, and differentiation by means of reactive oxygen and nitrogen species (RONS) created by plasma and deposited into the cell environment. The impact of the plasma downstream products NO2- and NO3- on the expressions of the focal adhesion's genes, syndecans, and collagens was observed to be prominent. On the other hand, the differentiation of fibroblasts to myofibroblasts was mainly initiated by ROS produced by the plasma. In addition, the ability of plasma to locally permeabilize fibroblast cells was demonstrated. During proliferative cell treatment, plasma can simultaneously induce cell membrane permeabilization (d ∼ 7.3 nm) by the species OH and H2O2. The choice for a plasma or a plasma-aerosol configuration thus allows the possibility to change the spatial chemistry of drug delivery molecules and thus to locally deliver drugs. Accordingly, this study offers a pivotal step toward plasma-assisted wound healing advanced by drug delivery.

The sedative effect of intranasal administration of medetomidine using a mucosal atomization device in Japanese White rabbits.

To prevent aspiration in Japanese White (JW) rabbits, the maximum single volume of medetomidine administered intranasally is 0.3 mL per nostril using a mucosal atomization device (MAD). This study aimed to examine the sedative effect of intranasal administration of medetomidine using MAD in eight healthy female JW rabbits. Each rabbit received intranasal atomization (INA) of saline (Control treatment) along with three doses of 1 mg/mL medetomidine (0.3 mL to one nostril [MED0.3 treatment]; 0.3 mL each to both nostrils [MED0.6 treatment]; 0.3 mL twice to both nostrils [MED1.2 treatment]), with a washout period of at least 7 days between treatments. The actual doses of medetomidine were 82 (75-84) µg/kg (median [25th-75th percentile]), 163 (156-168) µg/kg, and 323 (295-343) µg/kg for the MED0.3, MED0.6, and MED1.2 treatments, respectively. A medetomidine-dose dependent sedative effect was detected, and the loss of righting reflex (LRR) was achieved in one rabbit at 18 min, seven rabbits at 11 (9-18) min, and eight rabbits at 7 (4-18) min after the MED0.3, MED0.6, and MED1.2 treatments, respectively. The LRR was maintained for 63 (29-71) min and 83 (68-101) min after the MED0.6 and MED1.2 treatments, respectively. Additionally, the INA of medetomidine produced a significant dose-dependent cardiorespiratory depression including a decrease in pulse rate, respiratory rate, percutaneous oxygen saturation, and arterial partial pressure of oxygen, and an increase in arterial partial pressure of carbon dioxide in the rabbits.

Efficacy of ceftazidime in a murine model following a lethal aerosol exposure to Burkholderia pseudomallei.

Melioidosis is an endemic disease in numerous tropical regions. Additionally, the bacterium that causes melioidosis, Burkholderia pseudomallei, has potential to be used as a biological weapon. Therefore, development of effective and affordable medical countermeasures to serve regions affected by the disease and to have medical countermeasures available in the event of a bioterrorism attack remains critical. The current study evaluated the efficacy of eight distinct acute phase ceftazidime treatment regimens administered therapeutically in the murine model. At the conclusion of the treatment period, survival rates were significantly greater in several of the treated groups when compared to the control group. Pharmacokinetics of a single dose of ceftazidime were examined at 150 mg/kg, 300 mg/kg, and 600 mg/kg and were compared to an intravenous clinical dose administered at 2000 mg every eight hours. The clinical dose has an estimated 100% fT > 4*MIC which exceeded the highest murine dose of 300 mg/kg every six hours at 87.2% fT > 4*MIC. Based upon survival at the end of the treatment regimen and supplemented by pharmacokinetic modeling, a daily dose of 1200 mg/kg of ceftazidime, administered every 6 h at 300 mg/kg, provides protection in the acute phase of inhalation melioidosis in the murine model.

Comparative assessment of electronic nicotine delivery systems aerosol and cigarette smoke on endothelial cell migration: The Replica Project.

Cigarette smoking is associated with impairment of repair mechanisms necessary for vascular endothelium homeostasis. Reducing the exposure to smoke toxicants may result in the mitigation of the harmful effect on the endothelium and cardiovascular disease development. Previous investigations evaluated in vitro the effect of electronic cigarette (EC) compared with cigarette smoke demonstrating a significant reduction in human umbilical vein endothelial cells (HUVECs) migration inhibition following EC aerosol exposure. In the present study, we replicated one of these studies, evaluating the effects of cigarette smoke on endothelial cell migration compared with aerosol from EC and heated tobacco products (HTPs). We performed an in vitro scratch wound assay on endothelial cells with a multi-center approach (ring-study) to verify the robustness and reliability of the results obtained in the replicated study, also testing the effect of aerosol from two HTPs on endothelial cells. Consistently with the original study, we observed a substantial reduction of the effects of aerosol from EC and HTPs on endothelial cell migration compared with cigarette smoke. While cigarette smoke reduced endothelial wound healing ability already at low concentrations (12.5%) and in a concentration-dependent manner, EC and HTPs aerosol showed no effect on endothelial cells until 80%-100% concentrations. In conclusion, our study further confirms the importance of EC and tobacco heated products as a possible harm reduction strategy for cardiovascular diseases development in smokers.

The pulmonary pharmacokinetics and anti-inflammatory effects after intratracheal and intravenous administration of Chuankezhi injection.

BACKGROUND: Chuankezhi injection (CKZ) is a traditional Chinese medicine for the treatment of respiratory diseases and has been often used off-label as a nebulization therapy. However, little is known about the aerosolization performance and pulmonary fate of the inhaled CKZ. This study aimed to evaluate the aerodynamic characteristics of nebulizer generated aerosols and to compare the properties of pharmacokinetics, lung distribution and anti-inflammation effects of CKZ after intratracheal and intravenous administration. METHODS: The nebulization performance was evaluated in vitro based on the aerodynamic particle size distribution and aerosol output. The concentrations of epimedins A, B, C and icariin, the main active ingredients of CKZ, in plasma, bronchoalveolar lavage fluids (BALF) and lung tissues were measured by LC-MS/MS analysis. The pulmonary anti-inflammatory efficacy were tested using LPS-induced pulmonary inflammation mice model as indicated by the total cells counts, and the levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in BALF. RESULTS: The aerosols of CKZ generated by a commercial nebulizer showed excellent aerodynamic properties and delivery output. Following intratracheal instillation of CKZ, epidemins A, B and C, and icariin, were absorbed into the bloodstream with the mean absorption time varying from 101.8 min to 271.8 min, and their absolute bioavailabilities ranging from 26.4 % to 104 %. The instillation of CKZ increased the lung to plasma concentration ratios by 25.5-718 folds compared to intravenous administration, leading to improved and prolonged local anti-inflammatory effects. CONCLUSION: Nebulization therapy of CKZ could be a promising alternative to the injectable counterpart.

Effect of Sodium Hypochlorite in Dental Unit Waterline on Aerosolized Bacteria Generated from Endodontic Procedures.

INTRODUCTION: Aerosol generation in a dental setting is a critical concern, and approaches that aim at decreasing bacterial load in aerosols are of high priority for dental professionals. The objectives of this study were to evaluate the relative effect of various endodontic procedures on the generation and dissemination of aerosols and the effect of 0.1% sodium hypochlorite (NaOCl) in dental unit waterlines (DUWLs) on the bacterial load in the generated aerosols in a clinical setting. METHODS: The study was completed in 2 phases. The classic passive sampling technique using brain-heart infusion agar plates was used. Agar plates were strategically placed throughout the operatory at predefined locations. In phase 1, to evaluate the effect of different endodontic procedures on the generation and dissemination of aerosols, we collected a total of 38 samples. After baseline collection, test samples were collected during vital pulp therapy (VPT) full pulpotomy (n = 10), nonsurgical root canal therapy (NSRCT, n = 10), surgical root canal therapy (SRCT, n = 10), and incision and drainage (n = 8) procedures. Bacterial growth was expressed as colony-forming units at 48 hours after sample collection. Data were analyzed using 1-way analysis of variance with the Tukey multiple comparison post hoc test. In phase 2, to evaluate the effect of 0.1% NaOCl in the DUWL on the bacterial load in the generated aerosols, a total of 30 samples were collected. All procedures including VPT (n = 10), NSRCT (n = 10), and SRCT (n = 10) were performed with 0.1% NaOCl in the DUWL. Bacterial growth was expressed as colony-forming units at 48 hours after sample collection. Data were analyzed using 2-way analysis of variance with the Tukey multiple comparison post hoc test. RESULTS: All endodontic procedures generated aerosols at all tested locations, except incision and drainage. Aerosols were disseminated as far as 3 m from the patient's head with no significant difference between various locations (P > .05). VPT procedures generated the maximum number of aerosols compared with NSRCT and SRCT. Adding 0.1% NaOCl to DUWLs significantly reduced the bacterial load in the generated aerosols in all treatment groups compared with groups treated with untreated waterlines (P < .05). No significant difference was noted in the bacterial load between all groups with treated waterlines (P > .05). CONCLUSIONS: All tested endodontic procedures led to the generation and dissemination of contaminated aerosols, and the addition of 0.1% NaOCl as a biocide to the DUWL led to a statistically significant reduction in the bacterial load.

Pulmonary drug delivery and retention: A computational study to identify plausible parameters based on a coupled airway-mucus flow model.

Pulmonary drug delivery systems rely on inhalation of drug-laden aerosols produced from aerosol generators such as inhalers, nebulizers etc. On deposition, the drug molecules diffuse in the mucus layer and are also subjected to mucociliary advection which transports the drugs away from the initial deposition site. The availability of the drug at a particular region of the lung is, thus, determined by a balance between these two phenomena. A mathematical analysis of drug deposition and retention in the lungs is developed through a coupled mathematical model of aerosol transport in air as well as drug molecule transport in the mucus layer. The mathematical model is solved computationally to identify suitable conditions for the transport of drug-laden aerosols to the deep lungs. This study identifies the conditions conducive for delivering drugs to the deep lungs which is crucial for achieving systemic drug delivery. The effect of different parameters on drug retention is also characterized for various regions of the lungs, which is important in determining the availability of the inhaled drugs at a target location. Our analysis confirms that drug delivery efficacy remains highest for aerosols in the size range of 1-5 µm. Moreover, it is observed that amount of drugs deposited in the deep lung increases by a factor of 2 when the breathing time period is doubled, with respect to normal breathing, suggesting breath control as a means to increase the efficacy of drug delivery to the deep lung. A higher efficacy also reduces the drug load required to be inhaled to produce the same health effects and hence, can help in minimizing the side effects of a drug.

Inhalation of Silver Silicate Nanoparticles Leads to Transient and Differential Microglial Activation in the Rodent Olfactory Bulb.

Engineered silver nanoparticles (AgNPs), including silver silicate nanoparticles (Ag-SiO2 NPs), are used in a wide variety of medical and consumer applications. Inhaled AgNPs have been found to translocate to the olfactory bulb (OB) after inhalation and intranasal instillation. However, the biological effects of Ag-SiO2 NPs and their potential nose-to-brain transport have not been evaluated. The present study assessed whether inhaled Ag-SiO2 NPs can elicit microglial activation in the OB. Adult Sprague-Dawley rats inhaled aerosolized Ag-SiO2 NPs at a concentration of 1 mg/ml for 6 hours. On day 0, 1, 7, and 21 post-exposure, rats were necropsied and OB were harvested. Immunohistochemistry on OB tissues were performed with anti-ionized calcium-binding adapter molecule 1 and heme oxygenase-1 as markers of microglial activation and oxidative stress, respectively. Aerosol characterization indicated Ag-SiO2 NPs were sufficiently aerosolized with moderate agglomeration and high-efficiency deposition in the nasal cavity and olfactory epithelium. Findings suggested that acute inhalation of Ag-SiO2 NPs elicited transient and differential microglial activation in the OB without significant microglial recruitment or oxidative stress. The delayed and differential pattern of microglial activation in the OB implied that inhaled Ag-SiO2 may have translocated to the central nervous system via intra-neuronal pathways.

Influenza A Virus Production in Mouse Lung Is Inhibited by Inhalation of Aerosol Polyethylenimine/Short Hairpin RNA Plasmid Complexes.

Influenza pandemics are a global threat to human health, with existing vaccines and antiviral drugs providing limited protection. There is an urgent need for new prophylactic and treatment strategies. In this study, 12 short hairpin (sh)RNAs targeting conserved regions of influenza A virus (IAV) matrix protein (M)2, nucleocapsid protein (NP), nonstructural protein (NS), and polymerase acidic (PA) were synthesized, and their effects on IAV replication in cells were investigated using Madin-Darby canine kidney (MDCK) cells transfected with the shRNA plasmids. Additionally, mice were administered a polyethyleneimine PEI/pLKD-NP-391 complex in aerosol form and then infected with AIV, and viral particles in the mouse lung were detected. IAV production was markedly lower in MDCK cells transfected with pLKD-M-121, pLKD-M-935, pLKD-NP-391, pLKD-NP-1291, pLKD-PA-1365, and pLKD-PA-1645 plasmids than in control cells (p < 0.01). The viral load in MDCK cells was decreased by transfection of plasmids pLKD-M-121 (p < 0.05) and pLKD-M-935, pLKD-NP-391, pLKD-NP-1291, pLKD-PA-1365, and pLKD PA-1645 (p < 0.01) compared to an empty plasmid. The viral load was significantly lower in the lungs of mice transfected with pLKD-NP-391 than in the control plasmid and mock transfection groups (p < 0.01 and p < 0.05, respectively). Thus, IAV production was inhibited by shRNAs targeting matrix IAV components; moreover, inhalation of a PEI/pLKD-NP-391 complex in aerosol form suppressed IAV production in infected mice. Thus, these shRNAs can be effective for the prevention and treatment of influenza virus infection.

Aerosol delivery, but not intramuscular injection, of adenovirus-vectored tuberculosis vaccine induces respiratory-mucosal immunity in humans.

BackgroundAdenovirus-vectored (Ad-vectored) vaccines are typically administered via i.m. injection to humans and are incapable of inducing respiratory mucosal immunity. However, aerosol delivery of Ad-vectored vaccines remains poorly characterized, and its ability to induce mucosal immunity in humans is unknown. This phase Ib trial evaluated the safety and immunogenicity of human serotype-5 Ad-vectored tuberculosis (TB) vaccine (AdHu5Ag85A) delivered to humans via inhaled aerosol or i.m. injection.MethodsThirty-one healthy, previously BCG-vaccinated adults were enrolled. AdHu5Ag85A was administered by single-dose aerosol using Aeroneb Solo Nebulizer or by i.m. injection. The study consisted of the low-dose (LD) aerosol, high-dose (HD) aerosol, and i.m. groups. The adverse events were assessed at various times after vaccination. Immunogenicity data were collected from the peripheral blood and bronchoalveolar lavage samples at baseline, as well as at select time points after vaccination.ResultsThe nebulized aerosol droplets were < 5.39 µm in size. Both LD and HD of AdHu5Ag85A administered by aerosol inhalation and i.m. injection were safe and well tolerated. Both aerosol doses, particularly LD, but not i.m., vaccination markedly induced airway tissue-resident memory CD4+ and CD8+ T cells of polyfunctionality. While as expected, i.m. vaccination induced Ag85A-specific T cell responses in the blood, the LD aerosol vaccination also elicited such T cells in the blood. Furthermore, the LD aerosol vaccination induced persisting transcriptional changes in alveolar macrophages.ConclusionInhaled aerosol delivery of Ad-vectored vaccine is a safe and superior way to elicit respiratory mucosal immunity. This study warrants further development of aerosol vaccine strategies against respiratory pathogens, including TB and COVID-19.Trial registrationClinicalTrial.gov, NCT02337270.FundingThe Canadian Institutes for Health Research (CIHR) and the Natural Sciences and Engineering Research Council of Canada funded this work.

Real-time monitoring of cellular oxidative stress during aerosol sampling: a proof of concept study.

The Portable In Vitro Exposure Cassette (PIVEC) was developed for on-site air quality testing using lung cells. Here, we describe the incorporation of a sensor within the PIVEC for real time monitoring of cellular oxidative stress during exposure to contaminated air. An electrochemical, enzymatic biosensor based on cytochrome c (cyt c) was selected to measure reactive oxygen species (ROS), including hydrogen peroxide and super oxides, due to the stability of signal over time. Human A549 lung cells were grown at the air-liquid interface and exposed within the PIVEC to dry 40 nm copper nanoparticle aerosols for 10 minutes. The generation of ROS compounds was measured during exposure and post-exposure for one hour using the biosensor and compared to intracellular ROS determined using the 2',7'-dichlorodihydrofluoroscein diacetate (DCFH-DA) assay. A similar increase in oxidative stress upon aerosol exposure was measured using both the cyt c biosensor and DCFH-DA assay. The incorporation of a biosensor within the PIVEC is a unique, first-of-its-kind system designed to monitor the real-time effect of aerosols.

Developing inhaled drugs for respiratory diseases: A medicinal chemistry perspective.

Despite the devastating impact of many lung diseases on human health, there is still a significant unmet medical need in respiratory diseases, for which inhaled delivery represents a crucial strategy. More guidance on how to design and carry out multidisciplinary inhaled projects is needed. When designing inhaled drugs, the medicinal chemist must carefully balance the physicochemical properties of the molecule to achieve optimal target engagement in the lung. Although the medicinal chemistry strategy is unique for each project, and will change depending on multiple factors, such as the disease, target, systemic risk, delivery device, and formulation, general guidelines aiding inhaled drug design can be applied and are summarised in this review.

Assessment of in vitro kinetics and biological impact of nebulized trehalose on human bronchial epithelium.

Trehalose is added in drug formulations to act as fillers or improve aerosolization performance. Its characteristics as a carrier molecule have been explored; however, the fate of trehalose in human airway tissues has not been thoroughly investigated. Here, we investigated the fate of nebulized trehalose using in vitro human air-liquid bronchial epithelial cultures. First, a tracing experiment was conducted using 13C12-trehalose; we measured trehalose distribution in different culture compartments (apical surface liquid, epithelial culture, and basal side medium) at various time points following acute exposure to 13C12-labeled trehalose. We found that 13C12-trehalose was metabolized into 13C6-glucose. The data was then used to model the kinetics of trehalose disappearance from the apical surface of bronchial cultures. Secondly, we evaluated the potential adverse effects of nebulized trehalose on the bronchial cultures after they were acutely exposed to nebulized trehalose up to a level just below its solubility limit (50 g/100 g water). We assessed the ciliary beating frequency and histological characteristics. We found that nebulized trehalose did not lead to marked alteration in ciliary beating frequency and morphology of the epithelial cultures. The in vitro testing approach used here may enable the early selection of excipients for future development of inhalation products.

Evaluation of potential toxicity of Steriplant©N aerosolization toward human alveolar cells A459 in vitro.

Protection of patients against hospital-acquired infections is of major importance. Disinfection of magnetic resonance imaging suites is, due to their unique properties and environment particularly, difficult to implement. We developed an OPTI-JET CS MD 2ZE aerosolizator for disinfection of a magnetic resonance imaging suite using the electrolyzed oxidizing water biocide Steriplant©N. The disinfection of the magnetic resonance imaging suite with this system reduced from the number of colony formed unit/m3 air by 87% and 96% in 6 and 15 min of disinfection, respectively. It is well known that exposure of personnel or patients to aerosols may represent risk to the respiratory system; therefore, the aim of this study was to assess potential cytotoxicity and genotoxicity of Steriplant©N aerosolization toward human alveolar cells A459 in vitro. The A459 cells were exposed to aerosol containing different concentrations (50% and 100% v/v) of Steripalnt©N for 6 min in a chamber that had been constructed to simulate the conditions in the magnetic resonance imaging suite. The cytotoxicity was evaluated by measuring iodide uptake, and the genotoxicity was determined by measuring formation of phosphorylated H2AX histones, a marker for deoxyribonucleic acid double-strand breaks, immediately after the aerosolization and after 1, 4, and 24 h postincubation. The results demonstrated that aerosolization with Steriplant©N at conditions reflecting aerosolization in a magnetic resonance imaging suite is not cytotoxic and does not exhibit genotoxic potential in vitro.

Targeted Drug Delivery Technologies Potentiate the Overall Therapeutic Efficacy of an Indole Derivative in a Mouse Cystic Fibrosis Setting.

Inflammation plays a major role in the pathophysiology of cystic fibrosis (CF), a multisystem disease. Anti-inflammatory therapies are, therefore, of interest in CF, provided that the inhibition of inflammation does not compromise the ability to fight pathogens. Here, we assess whether indole-3-aldehyde (3-IAld), a ligand of the aryl hydrocarbon receptor (AhR), may encompass such an activity. We resorted to biopharmaceutical technologies in order to deliver 3-IAld directly into the lung, via dry powder inhalation, or into the gut, via enteric microparticles, in murine models of CF infection and inflammation. We found the site-specific delivery of 3-IAld to be an efficient strategy to restore immune and microbial homeostasis in CF organs, and mitigate lung and gut inflammatory pathology in response to fungal infections, in the relative absence of local and systemic inflammatory toxicity. Thus, enhanced delivery to target organs of AhR agonists, such as 3-IAld, may pave the way for the development of safe and effective anti-inflammatory agents in CF.

Robustness of aerosol delivery of amikacin liposome inhalation suspension using the eFlow® Technology.

The purpose of these studies was to understand the effect on product performance of batch-to-batch variability in both the amikacin liposome inhalation suspension (ALIS) formulation and its delivery device, the Lamira® nebulizer system, designed and manufactured by PARI (PARI Pharma GmbH, Munich, Germany). Three batches of ALIS spanning a range of lipid concentrations (43, 48 and 54 mg/mL) were tested with nine PARI inhalation devices that varied within the production process of the vibrating membrane with respect to hole geometry. Three hole geometry clusters were built including a geometry close to the mean geometry (median) and two geometries deviating from the mean geometry with smaller (smaller) and larger (larger) holes. The output parameters included the nebulization rate, the aerosol droplet size distribution, the liposome vesicle size post-nebulization, and the fraction of amikacin that remained encapsulated post-nebulization. Across the 27 experimental combinations of three formulation batches and nine devices, the nebulization time varied between 12 and 15 min with the fastest nebulization rate occurring with the combination of low lipid concentration and larger hole geometry (0.68 g/min) and the slowest nebulization rate occurring with the combination of high lipid concentration and the smaller hole geometry (0.59 g/min). The mean liposome vesicle size post-nebulization ranged from 269 to 296 nm across all experimental combinations which was unchanged from the control samples (276-292 nm). While all three batches contained > 99% encapsulated amikacin prior to nebulization, the nebulization process resulted in a consistent generation of ~ 35% unencapsulated amikacin (range: 33.8% to 37.6%). There was no statistically significant difference in the generated aerosol particle size distributions. The mass median aerodynamic diameters (MMAD) ranged from 4.78 µm to 4.98 µm, the geometric standard deviations (GSD) ranged from 1.61 to 1.66, and the aerosol fine particle fraction (FPF < 5 µm) ranged from 50.3 to 53.5%. The emitted dose (ED) of amikacin ranged from 473 to 523 mg (80.2 to 89.3% of loaded dose (LD)) and the fine particle dose (FPD < 5 µm) ranged from 244 to 278 mg (41.4 to 47.1% of label claim (LC)). In conclusion, while variations in the lipid concentration of the ALIS formulation and the device hole geometry had a small but significant impact on nebulization time, the critical aerosol performance parameters were maintained and remained within acceptable limits.