Intrapulmonary Administration Research Articles

Evaluation of the Effect of the Mycoplasma hyopneumoniae Live Vaccine (Strain 168) in Ningxiang Pigs

[Background/Objectives] Mycoplasma hyopneumoniae (M. hyopneumoniae) is widespread in the global swine industry, leading to significant economic losses, and is particularly severe in native Chinese pig breeds. The Ningxiang pig, a well-known native breed in China, is susceptible to M. hyopneumoniae, exhibiting high morbidity and mortality rates. This study was designed to evaluate the clinical effectiveness of the M. hyopneumoniae live vaccine (strain 168). [Methods] The vaccine was delivered to 7-day-old piglets in the farrowing room through intrapulmonary administration, and its efficacy was compared with that of the M. hyopneumoniae inactivated vaccine (strain J). Four experimental groups were designed: Group 1 (inactivated vaccine + inactivated vaccine), Group 2 (live vaccine + inactivated vaccine), Group 3 (live vaccine), and Group 4 (control), which was not vaccinated. The production performance of each group was measured, and the lung lesion scores and pneumonia lesion reduction rates were evaluated at slaughter. Nasal swabs and serum samples were collected on days 0, 14, 28, 56, 84, 112, and 140 to assess SIgA, IgG antibody levels, and the M. hyopneumoniae pathogen. [Results] The results showed that Group 3 had the best production performance and clinical outcomes, with the lowest average lung lesion score, of 4.43 ± 2.44, which was significantly different from the other groups (*** p < 0.001). [Conclusions] This study provided scientific evidence to support vaccination strategies for preventing and controlling the M. hyopneumoniae in native pig populations.

Fullerene and fullerene whisker are not carcinogenic to the lungs and pleura in rat long-term study after 2-week intra-tracheal intrapulmonary administration

Fullerene whiskers (FLW)s are thin rod-like structures composed of C60 and C70 fullerene (FL). The shape of FLWs suggests potential toxic effects including carcinogenicity to the lung and pleura, similar to effects elicited by asbestos and multi-walled carbon nanotubes (MWCNT)s. However, no long-term carcinogenic studies of FL or FLW have been conducted. In the present study we investigated the pulmonary and pleural carcinogenicity of FL and FLW. Twelve-week-old male F344 rats were administered 0.25 or 0.5 mg FL, FLW, MWCNT-7, and MWCNT-N by intra-tracheal intra-pulmonary spraying (TIPS). Acute lung lesions and carcinogenicity were analyzed at 1 and 104 weeks after 8 doses/15 days TIPS administration. At week 1, FLW, MWCNT-7, and MWCNT-N significantly increased alveolar macrophage infiltration. Expression of Ccl2 and Ccl3, reactive oxygen species production, and cell proliferation were significantly increased by administration of MWCNT-7 and MWCNT-N but not FL or FLW. At week 104, the incidence of bronchiolo-alveolar adenoma plus adenocarcinoma was significantly increased in the MWCNT-7 and MWCNT-N groups, and the incidence of mesothelioma was significantly increased in the MWCNT-7 group. No significant induction of pulmonary or pleural tumorigenesis was observed in the FL or FLW groups. The number of 8-OHdG-positive cells in the alveolar epithelium was significantly increased in the MWCNT-7 and MWCNT-N groups but not in the FL or FLW groups. FL and FLW did not exert pulmonary or pleural carcinogenicity in our study. In addition, oxidative DNA damage was implicated in MWCNT-induced lung carcinogenesis, suggesting that it may be a useful initial marker of carcinogenicity.

Pulsatile Right Ventricle to Pulmonary Artery Extracorporeal Membrane Oxygenation in a Pigs

Background: We investigated the impact of right ventricle to pulmonary artery extracorporeal membrane oxygenation in acute respiratory dysfunction with or without pulsatile flow. Methods: We used bronchoalveolar lavage with intrapulmonary administration of warm saline to establish a severe acute respiratory distress syndrome model (ratio of partial pressure of oxygen in arterial blood to the fraction of inspiratory oxygen concentration ratio <200) in eight piglets (mean body weight: 8.45±1.24 kg). The piglets were categorized into the pulsatile (N=4) and non-pulsatile extracorporeal membrane oxygenation groups (N=4). We started right ventricle to pulmonary artery extracorporeal membrane oxygenation with a 60 mL/kg/min flow to support the animals for 6 hours. We monitored hemodynamic data and blood gas levels for assessing base excess, and performed arterial blood sampling and electrocardiogram. Interleukin-6 and endotherlin-1 concentrations in blood plasma were evaluated before and after right ventricle to pulmonary artery extracorporeal membrane oxygenation. We compared the lung wet/dry weight ratio as a measure of pulmonary edema and collected lung tissue samples for the pathologically evaluating pneumocytes before and after right ventricle to pulmonary artery extracorporeal membrane oxygenation. Results: We maintained stable hemodynamics and extracorporeal membrane oxygenation flow above an arterial oxygen saturation of 85% in both groups. Pneumocyte evaluation showed clearly less pulmonary edema, pulmonary fibrosis, and inflammation. Interleukin-6 concentration was less in the pulsatile group than in the non-pulsatile group. Conclusions: Pulsatile right ventricle to pulmonary artery extracorporeal membrane oxygenation was less vasoconstrictive and maintained more effective oxygenated pulmonary flow. It ameliorates pulmonary circulation and facilitates recovery from acute respiratory failure.

Intrapulmonary administration of recombinant activated factor VII in pediatric, adolescent, and young adult oncology and hematopoietic cell transplant patients with pulmonary hemorrhage.

Diffuse alveolar hemorrhage (DAH) is a devastating disease process with 50-100% mortality in oncology and hematopoietic cell transplant (HCT) recipients. High concentrations of tissue factors have been demonstrated in the alveolar wall in acute respiratory distress syndrome and DAH, along with elevated levels of tissue factor pathway inhibitors. Activated recombinant factor VII (rFVIIa) activates the tissue factor pathway, successfully overcoming the tissue factor pathway inhibitor (TFPI) inhibition of activation of Factor X. Intrapulmonary administration (IP) of rFVIIa in DAH is described in small case series with successful hemostasis and minimal complications. We completed a single center retrospective descriptive study of treatment with rFVIIa and outcomes in pediatric oncology and HCT patients with pulmonary hemorrhage at a quaternary hematology/oncology hospital between 2011 and 2019. We aimed to assess the safety and survival of patients with pulmonary hemorrhage who received of IP rFVIIa. We identified 31 patients with pulmonary hemorrhage requiring ICU care. Thirteen patients received intrapulmonary rFVIIa, while eighteen patients did not. Overall, 13 of 31 patients (41.9%) survived ICU discharge. ICU survival (n=6) amongst those in the IP rFVIIa group was 46.2% compared to 38.9% (n=7) in those who did not receive IP therapy (p=0.69). Hospital survival was 46.2% in the IP group and 27.8% in the non-IP group (p=0.45). There were no adverse events noted from use of IP FVIIa. Intrapulmonary rFVIIa can be safely administered in pediatric oncology patients with pulmonary hemorrhage and should be considered a viable treatment option for these patients.

Novel Dry Hyaluronic Acid-Vancomycin Complex Powder for Inhalation, Useful in Pulmonary Infections Associated with Cystic Fibrosis.

Polyelectrolyte-drug complexes are interesting alternatives to improve unfavorable drug properties. Vancomycin (VAN) is an antimicrobial used in the treatment of methicillin-resistant Staphylococcus aureus pulmonary infections in patients with cystic fibrosis. It is generally administered intravenously with a high incidence of adverse side effects, which could be reduced by intrapulmonary administration. Currently, there are no commercially available inhalable formulations containing VAN. Thus, the present work focuses on the preparation and characterization of an ionic complex between hyaluronic acid (HA) and VAN with potential use in inhalable formulations. A particulate-solid HA-VAN25 complex was obtained by spray drying from an aqueous dispersion. FTIR spectroscopy and thermal analysis confirmed the ionic interaction between HA and VAN, while an amorphous diffraction pattern was observed by X-ray. The powder density, geometric size and morphology showed the suitable aerosolization and aerodynamic performance of the powder, indicating its capability of reaching the deep lung. An in vitro extended-release profile of VAN from the complex was obtained, exceeding 24 h. Microbiological assays against methicillin-resistant and -sensitive reference strains of Staphylococcus aureus showed that VAN preserves its antibacterial efficacy. In conclusion, HA-VAN25 exhibited interesting properties for the development of inhalable formulations with potential efficacy and safety advantages over conventional treatment.

Targeted DPPC/DMPG surface-modified voriconazole lipid nanoparticles control invasive pulmonary aspergillosis in immunocompromised population: in-vitro and in-vivo assessment

Invasive pulmonary aspergillosis (IPA) is the most devastating Aspergillus-related lung disease. Voriconazole (VRZ) is the first-line treatment against IPA. Despite availability in oral and parenteral dosage forms, risks of systemic toxicity dictate alternative pulmonary administration. Inspired by natural lung surfactants, dipalmitoylphosphatidylcholine/dimyristoylphosphatidylglycerol (DPPC/DMPG) surface-modified lipid nanoparticles (LNPs) were scrutinized for pulmonary administration. DPPC/DMPG-VRZ-LNPs prepared using ultrasonication/thin film hydration were investigated for colloidal properties over 3-month shelf storage. They were stable with a slight change in entrapment efficiency. They provided a sustained VRZ release over 24 h, with a rapid initial release. In vitro aerosolization indicated higher percentages of VRZ deposited on stages corresponding to secondary bronchi and alveolar ducts. Moreover, intrapulmonary administration maintained high lung VRZ concentration (27 ± 1.14 µg/g) after 6 h. A preclinical study using a cyclophosphamide-induced neutropenic rat model demonstrated a 3-fold reduction in BALF-Galactomannan down to 0.515 ± 0.22 µg/L confirming DPPC/DMPG-VRZ-LNPs potential in hyphal growth inhibition. Histopathological examination of infected/nontreated lung sections exhibited dense fungal load inside alveoli and blood vessels indicating massive tissue and angio-invasiveness. Nevertheless, DPPC/DMPG-VRZ-LNPs-treated animals displayed minimal hyphae with no signs of invasiveness. The developed bioinspired nanoparticles serve as prospective bioactive nanocarrier candidates for pulmonary administration of VRZ in the management of IPA.

Heterogenous Intrapulmonary Distribution of Aerosolized Model Compounds in Mice with Bleomycin-Induced Pulmonary Fibrosis.

Background: A distinctive pathological feature of idiopathic pulmonary fibrosis (IPF) is the aberrant accumulation of extracellular matrix components in the alveoli in abnormal remodeling and reconstruction following scarring of the alveolar structure. The current antifibrotic agents used for IPF therapy frequently result in systemic side effects because these agents are distributed, through the blood, to many different tissues after oral administration. In contrast to oral administration, the intrapulmonary administration of aerosolized drugs is believed to be an efficient method for their direct delivery to the focus sites in the lungs. However, how fibrotic lesions alter the distribution of aerosolized drugs following intrapulmonary administration remains largely unknown. In this study, we evaluate the intrapulmonary distribution characteristics of aerosolized model compounds in mice with bleomycin-induced pulmonary fibrosis through imaging the organs and alveoli. Methods: Aerosolized model compounds were administered to mice with bleomycin-induced pulmonary fibrosis using a Liquid MicroSprayer®. The intrapulmonary distribution characteristics of aerosolized model compounds were evaluated through several imaging techniques, including noninvasive lung imaging using X-ray computed tomography, ex vivo imaging using zoom fluorescence microscopy, frozen tissue section observation, and three-dimensional imaging with tissue-clearing treatment using confocal laser microscopy. Results: In fibrotic lungs, the aerosolized model compounds were heterogeneously distributed. In observations of frozen tissue sections, model compounds were observed only in the fibrotic foci near airless spaces called honeycombs. In three-dimensional imaging of cleared tissue from fibrotic lungs, the area of the model compound in the alveolar space was smaller than in healthy lungs. Conclusion: The intrapulmonary deposition of extracellular matrix associated with pulmonary fibrosis limits the intrapulmonary distribution of aerosolized drugs. The development of delivery systems for antifibrotic agents to improve the distribution characteristics in fibrotic foci is necessary for effective IPF therapy.

Systemic lupus erythematosus with diffuse alveolar hemorrhage.

Systemic lupus erythematosus with diffuse alveolar hemorrhage.

A Mouse Model of Pulmonary Fibrosis Induced by Nasal Bleomycin Nebulization.

Pulmonary fibrosis is characteristic of several human lung diseases that arise from various causes. Given that treatment options are fairly limited, mouse models continue to be an important tool for developing new anti-fibrotic strategies. In this study, intrapulmonary administration of bleomycin (BLM) is carried out by nasal nebulization to create a mouse model of pulmonary fibrosis that closely mimics clinical disease characteristics. C57BL/6 mice received BLM (7 U/mL, 30 min/day) by nasal nebulization for 3 consecutive days and were sacrificed on day 9, 16, or 23 to observe inflammatory and fibrotic changes in lung tissue. Nasal aerosolized BLM directly targeted the lungs, resulting in widespread and uniform lung inflammation and fibrosis. Thus, we successfully generated an experimental mouse model of typical human pulmonary fibrosis. This method could easily be used to study the effects of the administration of various nasal aerosols on lung pathophysiology and validate new anti-inflammatory and anti-fibrotic treatments.

Performance of Cell-Penetrating Peptides Anchored to Polysaccharide Platforms Applied via Various Mucosal Routes as an Absorption Enhancer.

We have been investigating the potential of cell-penetrating peptides anchored to polymeric platforms as a novel absorption enhancer which delivers biologics into systemic circulation via mucosal routes. Our previous mouse experiments demonstrated that hyaluronic acid modified with l-octaarginine, a typical cell-penetrating peptide, via a tetraglycine spacer significantly enhanced the mucosal absorption of protein drugs applied into the nasal cavities, irrespective of the molecular weights (Mw) of the drugs. The present study evaluated the performance of tetraglycine-l-octaarginine-linked hyaluronic acid applied via various mucosal routes. Somatropin (Mw: ca. 22.1 kDa) was moderately absorbed from the lung mucosa, and the mean absolute bioavailability (BA) reached 19% under enhancer-free conditions; nevertheless, its BA under intranasal administration was approximately 1% or less. Its BA significantly elevated to 46% on average through intrapulmonary coadministration with tetraglycine-l-octaarginine-linked hyaluronic acid. When the administration site was replaced with the oral cavities, an extreme reduction in somatropin absorption was observed with a mean BA of 0.056% under enhancer-free conditions. Intraoral coadministration with tetraglycine-l-octaarginine-linked hyaluronic acid resulted in a 6.3-fold elevation of somatropin absorption with statistical significance. A similar enhancement was observed under intrarectal administration with a further reduction in BA. On the other hand, the hyaluronic acid derivative did not exhibit the absorption-enhancing ability under intragastric administration, probably due to the lack of stabilization effects against enzyme-susceptible biologics. The results indicated that the intrapulmonary route was suitable for maximizing the mucosal absorption of biologics, and that there was a likelihood of the intraoral route with user convenience. When somatropin was substituted with fluorescein isothiocyanate-conjugated dextran with an average Mw range of 4-70 kDa, similar phenomena were observed under intrapulmonary and intranasal administration. BA decreased with an increase in the Mw of dextran; however, the ratio of BA under enhancer-present conditions to that under enhancer-free conditions was consistently around 3, indicating that the performance of the hyaluronic acid derivative was Mw-independent, irrespective of the administration route.

Benzodiazepines in the Management of Seizures and Status Epilepticus: A Review of Routes of Delivery, Pharmacokinetics, Efficacy, and Tolerability.

Status epilepticus (SE) is an acute, life-threatening medical condition that requires immediate, effective therapy. Therefore, the acute care of prolonged seizures and SE is a constant challenge for healthcare professionals, in both the pre-hospital and the in-hospital settings. Benzodiazepines (BZDs) are the first-line treatment for SE worldwide due to their efficacy, tolerability, and rapid onset of action. Although all BZDs act as allosteric modulators at the inhibitory gamma-aminobutyric acid (GABA)A receptor, the individual agents have different efficacy profiles and pharmacokinetic and pharmacodynamic properties, some of which differ significantly. The conventional BZDs clonazepam, diazepam, lorazepam and midazolam differ mainly in their durations of action and available routes of administration. In addition to the common intravenous, intramuscular and rectal administrations that have long been established in the acute treatment of SE, other administration routes for BZDs—such as intranasal administration—have been developed in recent years, with some preparations already commercially available. Most recently, the intrapulmonary administration of BZDs via an inhaler has been investigated. This narrative review provides an overview of the current knowledge on the efficacy and tolerability of different BZDs, with a focus on different routes of administration and therapeutic specificities for different patient groups, and offers an outlook on potential future drug developments for the treatment of prolonged seizures and SE.Graphical

Aspergillus Utilizes Extracellular Heme as an Iron Source During Invasive Pneumonia, Driving Infection Severity.

Depriving microbes of iron is critical to host defense. Hemeproteins, the largest source of iron within vertebrates, are abundant in infected tissues in aspergillosis due to hemorrhage, but Aspergillus species have been thought to lack heme import mechanisms. We hypothesized that heme provides iron to Aspergillus during invasive pneumonia, thereby worsening the outcomes of the infection. We assessed the effect of heme on fungal phenotype in various in vitro conditions and in a neutropenic mouse model of invasive pulmonary aspergillosis. In mice with neutropenic invasive aspergillosis, we found a progressive and compartmentalized increase in lung heme iron. Fungal cells cultured under low iron conditions took up heme, resulting in increased fungal iron content, resolution of iron starvation, increased conidiation, and enhanced resistance to oxidative stress. Intrapulmonary administration of heme to mice with neutropenic invasive aspergillosis resulted in markedly increased lung fungal burden, lung injury, and mortality, whereas administration of heme analogs or heme with killed Aspergillus did not. Finally, infection caused by fungal germlings cultured in the presence of heme resulted in a more severe infection. Invasive aspergillosis induces local hemolysis in infected tissues, thereby supplying heme iron to the fungus, leading to lethal infection.

Improvement of the pharmacokinetics and antifibrotic effects of nintedanib by intrapulmonary administration of a nintedanib–hydroxypropyl-γ-cyclodextrin inclusion complex in mice with bleomycin-induced pulmonary fibrosis

Idiopathic pulmonary fibrosis is a chronic lung disease that is characterized by progressive abnormal reprogramming following injury of the pulmonary structure. In this study, we prepared a nintedanib (antifibrotic agent) and cyclodextrin (CyD) inclusion complex to improve the pharmacokinetics and antifibrotic effects of nintedanib following intrapulmonary administration. Hydroxypropyl-γ-CyD (HP-γ-CyD) enhanced the solubility of nintedanib without cytotoxic effects on WI-38 cells (lung fibroblasts) and NCI-H441 cells (alveolar epithelium model). Compared with nintedanib ethanesulfonate salt, the nintedanib–HP-γ-CyD inclusion complex exhibited prolonged distribution in the lungs following intrapulmonary administration in mice with bleomycin-induced pulmonary fibrosis. In addition, compared with nintedanib ethanesulfonate salt, the nintedanib–HP-γ-CyD inclusion complex exhibited higher stability in the bronchoalveolar lavage fluid and lower permeability in NCI-H441 cell monolayers. These results suggested that the inclusion complexation of nintedanib into HP-γ-CyD improved its pharmacokinetics following intrapulmonary administration by increasing its stability in the lungs and reducing its permeability through the alveolar cell membrane. Intrapulmonary administration of the nintedanib–HP-γ-CyD inclusion complex significantly reduced the intrapulmonary hydroxyproline content and limited pathological fibrotic changes. Overall, this study indicates that antifibrotic agent–CyD inclusion complexation intended for intrapulmonary administration can be used to prolong distribution in the lungs and lead to the expansion of idiopathic pulmonary fibrosis therapy.

Management of diffuse alveolar hemorrhage in the hematopoietic stem cell transplantation population: A systematic review.

Pulmonary complications post-hematopoietic stem cell transplantation (HSCT) such as diffuse alveolar hemorrhage (DAH) can occur in 2% to 14% of HSCT patients and have a mortality greater than 80%. Diffuse alveolar hemorrhage is considered to be an inflammatory response; therefore, HSCT patients are primarily treated with different types of systemic corticosteroids with varying dosages. Other treatments currently reported in the literature in conjunction with corticosteroids include aminocaproic acid, recombinant factor VIIa (rFVIIa), and etanercept. This review highlights appropriate frontline and adjunctive treatment options for HSCT patients with DAH and outcomes for each intervention. To perform the review, the PubMed database was searched from inception through March 19, 2021, to identify potential studies using the search terms DAH and HSCT, DAH and hematopoietic cell transplant (HCT), DAH and stem cell, lung injury and HSCT, and lung injury and HCT. When applicable, references from articles identified in the search were also reviewed for inclusion. Much of the data identified were limited to retrospective cohort studies and case series. Based on the data available, the treatment approach should consist of corticosteroid therapy with a suggested methylprednisolone dose of 250mg daily followed by a 50% taper every 3days. Intrapulmonary administration of rFVIIa and intravenous administration of aminocaproic acid could be considered as adjunctive agents in those patients who do not promptly respond to corticosteroid therapy. Due to a lack of data specific to HSCT patients who develop DAH and the risk of infectious complications, etanercept should be avoided. Future studies should be designed as randomized controlled trials and examine the use of adjunctive therapies in the upfront setting for HSCT patients with DAH.

Intrapulmonary vaccination with delta-inulin adjuvant stimulates non-polarised chemotactic signalling and diverse cellular interaction

There is an urgent need for novel vaccination strategies to combat respiratory pathogens. Mucosal vaccine delivery is an attractive option as it directly targets the site of infection; however, preclinical development has been hindered by a lack of suitable mucosal adjuvants and a limited understanding of their immune effects in the lung environment. Herein, we define the early immune events following the intrapulmonary delivery of a vaccine incorporating the adjuvant delta-inulin. Analysis of the early inflammatory response showed vaccine-induced innate cell recruitment to lungs and local lymph nodes (LN) was transient and non-polarised, correlating with an increase in pulmonary chemotactic factors. Use of fluorescently labelled adjuvant revealed widespread tissue dissemination of adjuvant particles, coupled with broad cellular uptake and transit to the lung-draining LN by a range of innate immune cells. Mass cytometric analysis revealed extensive phenotypic changes in innate and adaptive cell subsets induced by vaccination; this included identification of unconventional lymphocytes such as γδ-T cells and MAIT cells that increased following vaccination and displayed an activated phenotype. This study details a comprehensive view of the immune response to intrapulmonary adjuvant administration and provides pre-clinical evidence to support delta-inulin as a suitable adjuvant for pulmonary vaccines.

DSPE-PEG polymers for improving pulmonary absorption of poorly absorbed macromolecules in rats and relative mechanism

Objective This study aims to investigate the potential of DSPE-PEG polymers (DSPE-PEG-OH and DSPE-PEG-SH) on improving absorption of poorly absorbable macromolecules via intrapulmonary administration and underlying mechanism. Methods In situ pulmonary absorption experiments were performed to investigate the absorption of model compounds after intrapulmonary administration to rats. The local membrane damage induced by these DSPE-PEG polymers were evaluated based on morphological observation of lung tissues and measurement of biological toxic markers in bronchoalveolar lavage fluid (BALF) postintrapulmonary delivery of DSPE-PEG polymers to rats. The underlying enhancement mechanism of these polymers was explored by investigating their effects on the pulmonary membrane fluidity and gene expression of tight junction associated proteins with fluorescence polarization and western blotting, respectively. Results Intrapulmonary delivery of these DSPE-PEG polymers significantly enhanced absorptions of poorly absorbed model drugs and did not induce serious damage to the pulmonary membranes of rats. Mechanistic studies demonstrated unaffected pulmonary membrane fluidity and up-regulated expression levels of tight junction-associated proteins by DSPE-PEG polymers, thus indicating that paracellular pathways might be included in the underlying mechanisms by which DSPE-PEG polymers exerted their enhancing actions on drug absorption. Conclusions These findings suggested that these DSPE-PEG polymers are potential for promoting absorptions of poorly absorbable macromolecules with no evidence of damage to the local pulmonary membranes of rats. Novelty statement In this study, DSPE-PEG-OH and DSPE-PEG-SH polymers, two DSPE-PEG2000 conjugates with different terminal groups demonstrated significant promoting effects on the absorption of poorly absorbed macromolecular drugs after intrapulmonary delivery to rats, and did not induce serious damage to the pulmonary membranes of rats. These DSPE-PEG polymers could statistically downregulate expression levels of tight junction-associated proteins (ZO-1 and occludin), indicating the underlying mechanism by which these polymers exerted their absorption enhancing actions through pulmonary epithelial paracellular pathways. Thus, this study exhibited prospective potential of these DSPE-PEG polymers in developing into dosage forms with the aim to improve the poor bioavailability of some poorly absorbed macromolecular drugs.

Pulmonary Targeting of Inhalable Moxifloxacin Microspheres for Effective Management of Tuberculosis.

In the present study, the objective was to attain a localized lung delivery of an anti-tubercular fluoroquinolone, moxifloxacin (MXF), targeting the alveolar macrophages through a non-invasive pulmonary route using inhalable microspheres as a dry powder inhaler approach. MXF-loaded poly (lactic-co-glycolic acid) (PLGA) microspheres (MXF-PLGA-MSs) were fabricated by solvent evaporation technique and optimized by using a central composite statistical design. The morphology and particle size, as well as the flowability of the optimized microspheres, were characterized. In addition, the aerosolization performance of the optimized formula was inspected using an Andersen cascade impactor. Furthermore, in vivo fate following intrapulmonary administration of the optimized formula was evaluated. The optimized MXF-PLGA-MSs were spherical in shape with a particle size of 3.16 µm, drug loading of 21.98% and entrapment efficiency of 78.0%. The optimized formula showed a mass median aerodynamic diameter (MMAD) of 2.85 ± 1.04 µm with a favorable fine particle fraction of 72.77 ± 1.73%, suggesting that the powders were suitable for inhalation. Most importantly, in vivo studies revealed that optimized MXF-PLGA-MSs preferentially accumulated in lung tissue as manifested by a two-fold increase in the area under the curve AUC0–24h, compared to plain drug. In addition, optimized MXF-PLGA-MS sustained drug residence in the lung for up to 24 h following inhalation, compared to plain drug. In conclusion, inhalable microspheres of MXF could be a promising therapeutic approach that might aid in the effective eradiation of tuberculosis along with improving patient adherence to the treatment.

Intrapulmonary administration of purified NEIL2 abrogates NF-κB–mediated inflammation

Aberrant or constitutive activation of nuclear factor kappa B (NF-κB) contributes to various human inflammatory diseases and malignancies via the upregulation of genes involved in cell proliferation, survival, angiogenesis, inflammation, and metastasis. Thus, inhibition of NF-κB signaling has potential for therapeutic applications in cancer and inflammatory diseases. We reported previously that Nei-like DNA glycosylase 2 (NEIL2), a mammalian DNA glycosylase, is involved in the preferential repair of oxidized DNA bases from the transcriptionally active sequences via the transcription-coupled base excision repair pathway. We have further shown that Neil2-null mice are highly sensitive to tumor necrosis factor α (TNFα)- and lipopolysaccharide-induced inflammation. Both TNFα and lipopolysaccharide are potent activators of NF-κB. However, the underlying mechanism of NEIL2's role in the NF-κB–mediated inflammation remains elusive. Here, we have documented a noncanonical function of NEIL2 and demonstrated that the expression of genes, such as Cxcl1, Cxcl2, Cxcl10, Il6, and Tnfα, involved in inflammation and immune cell migration was significantly higher in both mock- and TNFα-treated Neil2-null mice compared with that in the WT mice. NEIL2 blocks NF-κB's binding to target gene promoters by directly interacting with the Rel homology region of RelA and represses proinflammatory gene expression as determined by co-immunoprecipitation, chromatin immunoprecipitation, and electrophoretic mobility-shift assays. Remarkably, intrapulmonary administration of purified NEIL2 via a noninvasive nasal route significantly abrogated binding of NF-κB to cognate DNA, leading to decreased expression of proinflammatory genes and neutrophil recruitment in Neil2-null as well as WT mouse lungs. Our findings thus highlight the potential of NEIL2 as a biologic for inflammation-associated human diseases.

Kovid 19 - intrapulmonalni alkalni hidrogen-peroksid može trenutno da poveća oksigenaciju krvi

It has been shown that the new coronavirus infection is life-threatening for patients not because of the COVID-19 virus, but because of the complications it causes. The most dangerous complication of this disease is the airway obstruction syndrome, which occurs with atypical pneumonia. Blockage of the airways occurs due to the accumulation of excessively large amounts of mucus and pus in them and swelling of the lung tissue, so ventilation of the lungs with air becomes almost impossible. The sad outcome of respiratory obstruction is hypoxia and hypoxic brain damage. Under these conditions, extracorporeal membrane oxygenation remains the only known way to increase blood oxygenation. However, in 2021, it was shown that intra-pulmonary administration of a warm alkaline solution of hydrogen peroxide immediately turns mucus and pus into oxygen foam and increases blood oxygen saturation. The proposed technology is a new variant of emergency blood oxygenation in severe suffocation caused by blockage of the respiratory tract with mucus, pus and blood.

Three-Dimensional Imaging of Pulmonary Fibrotic Foci at the Alveolar Scale Using Tissue-Clearing Treatment with Staining Techniques of Extracellular Matrix.

Idiopathic pulmonary fibrosis is a progressive, chronic lung disease characterized by the accumulation of extracellular matrix proteins, including collagen and elastin. Imaging of extracellular matrix in fibrotic lungs is important for evaluating its pathological condition as well as the distribution of drugs to pulmonary focus sites and their therapeutic effects. In this study, we compared techniques of staining the extracellular matrix with optical tissue-clearing treatment for developing three-dimensional imaging methods for focus sites in pulmonary fibrosis. Mouse models of pulmonary fibrosis were prepared via the intrapulmonary administration of bleomycin. Fluorescent-labeled tomato lectin, collagen I antibody, and Col-F, which is a fluorescent probe for collagen and elastin, were used to compare the imaging of fibrotic foci in intact fibrotic lungs. These lung samples were cleared using the ClearT2 tissue-clearing technique. The cleared lungs were two dimensionally observed using laser-scanning confocal microscopy, and the images were compared with those of the lung tissue sections. Moreover, three-dimensional images were reconstructed from serial two-dimensional images. Fluorescent-labeled tomato lectin did not enable the visualization of fibrotic foci in cleared fibrotic lungs. Although collagen I in fibrotic lungs could be visualized via immunofluorescence staining, collagen I was clearly visible only until 40 μm from the lung surface. Col-F staining facilitated the visualization of collagen and elastin to a depth of 120 μm in cleared lung tissues. Furthermore, we visualized the three-dimensional extracellular matrix in cleared fibrotic lungs using Col-F, and the images provided better visualization than immunofluorescence staining. These results suggest that ClearT2 tissue-clearing treatment combined with Col-F staining represents a simple and rapid technique for imaging fibrotic foci in intact fibrotic lungs. This study provides important information for imaging various organs with extracellular matrix-related diseases.