scholarly journals Vibrating Mesh Nebulisation of Pro-Antimicrobial Peptides for Use in Cystic Fibrosis

Pharmaceutics ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 239 ◽  
Author(s):  
Éanna Forde ◽  
Graeme Kelly ◽  
Louise Sweeney ◽  
Deirdre Fitzgerald-Hughes ◽  
Ronan MacLoughlin ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Antimicrobial Peptides ◽  
Droplet Size ◽  
Droplet Size Distribution ◽  
Antimicrobial Activities ◽  
Physical Characteristics ◽  
Mechanically Ventilated ◽  
Delivery Times ◽  
Before And After ◽  
Spontaneously Breathing

Background: There has been considerable interest in the use of antimicrobial peptides (AMPs) as antimicrobial therapeutics in many conditions including cystic fibrosis (CF). The aim of this study is to determine if the prodrugs of AMPs (pro-AMPs) can be delivered to the lung by a vibrating mesh nebuliser (VMN) and whether the pro-AMP modification has any effect on delivery. Methods: Physical characteristics of the peptides (AMP and pro-AMP) and antimicrobial activity were compared before and after nebulisation. Droplet size distribution was determined by laser diffraction and cascade impaction. Delivery to a model lung was determined in models of spontaneously-breathing and mechanically-ventilated patients. Results: The physical characteristics and antimicrobial activities were unchanged after nebulisation. Mean droplet size diameters were below 5 μm in both determinations, with the fine particle fraction approximately 67% for both peptides. Approximately 25% of the nominal dose was delivered in the spontaneously-breathing model for both peptides, with higher deliveries observed in the mechanically-ventilated model. Delivery times were approximately 170 s per mL for both peptides and the residual volume in the nebuliser was below 10% in nearly all cases. Conclusions: These results demonstrate that the delivery of (pro-)AMPs to the lung using a VMN is feasible and that the prodrug modification is not detrimental. They support the further development of pro-AMPs as therapeutics in CF.

MODELING DROPLET SIZE DISTRIBUTION NEAR A NOZZLE OUTLET IN AN ICING WIND TUNNEL

2006 ◽  
Vol 16 (6) ◽  
pp. 673-686 ◽  
Author(s):  
Laszlo E. Kollar ◽  
Masoud Farzaneh ◽  
Anatolij R. Karev
Keyword(s):  
Wind Tunnel ◽  
Size Distribution ◽  
Droplet Size ◽  
Droplet Size Distribution ◽  
Nozzle Outlet

Frühgeborene unter maschineller Beatmung: Immunmodulatorischer Effekt der präventiven Gabe von Azithromycin

2020 ◽  
pp. 1-3
Author(s):  
Maximilian Jorczyk
Keyword(s):  
Very Low Birth Weight ◽  
Controlled Trial ◽  
Preterm Neonates ◽  
Double Blind ◽  
Mechanically Ventilated ◽  
Before And After ◽  
Anti Inflammatory ◽  
To Receive ◽  
Therapeutic Possibilities ◽  
Inflammatory Effect

<b>Introduction:</b> Macrolides have anti-inflammatory and immunomodulatory properties that give this class of antibiotics a role that differs from its classical use as an antibiotic, which opens new therapeutic possibilities. <b>Objective:</b> The aim of this study was to evaluate the anti-inflammatory effect of azithromycin in preventing mechanical ventilation (MV)-induced lung injury in very-low-birth-weight preterm neonates. <b>Methods:</b> This is a randomized, double-blind, placebo-controlled trial of preterm neonates who received invasive MV within 72 h of birth. Patients were randomized to receive intravenous azithromycin (at a dose of 10/mg/kg/day for 5 days) or placebo (0.9% saline) within 12 h of the start of MV. Two blood samples were collected (before and after intervention) for measurement of interleukins (ILs) and PCR for <i>Ureaplasma</i>. Patients were followed up throughout the hospital stay for the outcomes of death and bronchopulmonary dysplasia defined as need for oxygen for a period of ≥28 days of life (registered at ClinicalTrials.gov, No. NCT03485703). <b>Results:</b> Forty patients were analyzed in the azithromycin group and 40 in the placebo group. Five days after the last dose, serum IL-2 and IL-8 levels dropped significantly in the azithromycin group. There was a significant reduction in the incidence of death and O<sub>2</sub> dependency at 28 days/death in azithromycin-treated patients regardless of the detection of <i>Ureaplasma</i> in blood. <b>Conclusions:</b> Azithromycin has anti-inflammatory effects, with a decrease in cytokines after 5 days of use and a reduction in death and O<sub>2</sub> dependency at 28 days/death in mechanically ventilated preterm neonates.

scholarly journals The Impact of an Efflux Pump Inhibitor on the Activity of Free and Liposomal Antibiotics against Pseudomonas aeruginosa

Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 577
Author(s):  
Douweh Leyla Gbian ◽  
Abdelwahab Omri
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Efflux Pump ◽  
Antimicrobial Activities ◽  
Dilution Method ◽  
Efflux Pump Inhibitor ◽  
Signal Production ◽  
Lung Infections ◽  
The Impact ◽  
Microbroth Dilution

The eradication of Pseudomonas aeruginosa in cystic fibrosis patients has become continuously difficult due to its increased resistance to treatments. This study assessed the efficacy of free and liposomal gentamicin and erythromycin, combined with Phenylalanine arginine beta-naphthylamide (PABN), a broad-spectrum efflux pump inhibitor, against P. aeruginosa isolates. Liposomes were prepared and characterized for their sizes and encapsulation efficiencies. The antimicrobial activities of formulations were determined by the microbroth dilution method. Their activity on P. aeruginosa biofilms was assessed, and the effect of sub-inhibitory concentrations on bacterial virulence factors, quorum sensing (QS) signals and bacterial motility was also evaluated. The average diameters of liposomes were 562.67 ± 33.74 nm for gentamicin and 3086.35 ± 553.95 nm for erythromycin, with encapsulation efficiencies of 13.89 ± 1.54% and 51.58 ± 2.84%, respectively. Liposomes and PABN combinations potentiated antibiotics by reducing minimum inhibitory and bactericidal concentrations by 4–32 fold overall. The formulations significantly inhibited biofilm formation and differentially attenuated virulence factor production as well as motility. Unexpectedly, QS signal production was not affected by treatments. Taken together, the results indicate that PABN shows potential as an adjuvant of liposomal macrolides and aminoglycosides in the management of lung infections in cystic fibrosis patients.

scholarly journals Plant antimicrobial peptides: structures, functions, and applications

2021 ◽  
Vol 62 (1) ◽  
Author(s):  
Junpeng Li ◽  
Shuping Hu ◽  
Wei Jian ◽  
Chengjian Xie ◽  
Xingyong Yang
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Peptides ◽  
Agricultural Production ◽  
Food Additives ◽  
Antimicrobial Activities ◽  
Gram Positive Bacteria ◽  
Potential Applications ◽  
Potential Applicability ◽  
Bacteria And Fungi ◽  
Positively Charged

AbstractAntimicrobial peptides (AMPs) are a class of short, usually positively charged polypeptides that exist in humans, animals, and plants. Considering the increasing number of drug-resistant pathogens, the antimicrobial activity of AMPs has attracted much attention. AMPs with broad-spectrum antimicrobial activity against many gram-positive bacteria, gram-negative bacteria, and fungi are an important defensive barrier against pathogens for many organisms. With continuing research, many other physiological functions of plant AMPs have been found in addition to their antimicrobial roles, such as regulating plant growth and development and treating many diseases with high efficacy. The potential applicability of plant AMPs in agricultural production, as food additives and disease treatments, has garnered much interest. This review focuses on the types of plant AMPs, their mechanisms of action, the parameters affecting the antimicrobial activities of AMPs, and their potential applications in agricultural production, the food industry, breeding industry, and medical field.

scholarly journals 1458. Uncharted territories: applying “precision medicine” to understand the treacherous landscape of extensively and multidrug resistant (XDR and MDR) Pseudomonas aeruginosa in a patient with cystic fibrosis and lung transplantation

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S731-S731
Author(s):  
Laura J Rojas ◽  
Mohamad Yasmin ◽  
Jacquelynn Benjamino ◽  
Steven Marshall ◽  
Kailynn DeRonde ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Lung Transplantation ◽  
Precision Medicine ◽  
Clinical Sample ◽  
Phylogenetic Reconstruction ◽  
Multidrug Resistant ◽  
Population Diversity ◽  
Before And After ◽  
Research Grant

Abstract Background Pseudomonas aeruginosa is a persistent and difficult-to-treat pathogen in many patients, especially those with cystic fibrosis (CF). Herein, we describe our experience managing a young woman suffering from CF with XDR P. aeruginosa who underwent lung transplantation. We highlight the contemporary difficulties reconciling the clinical, microbiological, and genetic information. Methods Mechanism-based-susceptibility disk diffusion synergy testing with double and triple antibiotic combinations aided in choosing tailored antimicrobial combinations to control the infection in the pre-transplant period, create an effective perioperative prophylaxis regimen, and manage recurrent infections in the post-transplant period. Thirty-six sequential XDR and PDR P. aeruginosa isolates obtained from the patient within a 17-month period, before and after a double-lung transplant were analyzed by whole genome sequencing (WGS) and RNAseq in order to understand the genetic basis of the observed resistance phenotypes, establish the genomic population diversity, and define the nature of sequence changes over time Results Our phylogenetic reconstruction demonstrates that these isolates represent a genotypically and phenotypically heterogeneous population. The pattern of mutation accumulation and variation of gene expression suggests that a group of closely related strains was present in the patient prior to transplantation and continued to evolve throughout the course of treatment regardless of antibiotic usage.Our findings challenge antimicrobial stewardship programs that assist with the selection and duration of antibiotic regimens in critically ill and immunocompromised patients based on single-isolate laboratory-derived resistant profiles. We propose that an approach sampling the population of pathogens present in a clinical sample instead of single colonies be applied instead when dealing with XDR P. aeruginosa, especially in patients with CF. Conclusion In complex cases such as this, real-time combination testing and genomic/transcriptomic data could lead to the application of true “precision medicine” by helping clinicians choose the combination antimicrobial therapy most likely to be successful against a population of MDR pathogens present. Disclosures Federico Perez, MD, MS, Accelerate (Research Grant or Support)Merck (Research Grant or Support)Pfizer (Research Grant or Support) Robert A. Bonomo, MD, Entasis, Merck, Venatorx (Research Grant or Support)

CFD simulation of ultrasonic atomization pyrolysis reactor: the influence of droplet behaviors and solvent evaporation

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jian Wang ◽  
Jichuan Wu ◽  
Shouqi Yuan ◽  
Wei-Cheng Yan
Keyword(s):  
Flow Pattern ◽  
Size Distribution ◽  
Droplet Size ◽  
Cfd Simulation ◽  
Collection Efficiency ◽  
Great Influence ◽  
Droplet Size Distribution ◽  
Solvent Evaporation ◽  
Droplet Collision ◽  
Ultrasonic Atomization

Abstract Previous work showed that particle behaviors in ultrasonic atomization pyrolysis (UAP) reactor have a great influence on the transport and collection of particles. In this study, the effects of droplet behaviors (i.e. droplet collision and breakage) and solvent evaporation on the droplet size, flow field and collection efficiency during the preparation of ZnO particles by UAP were investigated. The collision, breakage and solvent evaporation conditions which affect the droplet size distribution and flow pattern were considered in CFD simulation based on Eulerian-Lagrangian method. The results showed that droplet collision and breakage would increase the droplet size, broaden the droplet size distribution and hinder the transport of droplets. Solvent evaporation obviously changed the flow pattern of droplets. In addition, both droplet behaviors and solvent evaporation reduced the collection efficiency. This study could provide detail information for better understanding the effect of droplet behaviors and solvent evaporation on the particle production process via UAP reactor.

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