Advancements in Acoustic Drug Delivery for Paranasal Sinuses: A Comprehensive Review

Available online 27 July 2023Chronic rhinosinusitis (CRS) impacts patients' quality of life and healthcare costs. Traditional methods of drug delivery, such as nasal sprays and irrigation, have limited effectiveness. Acoustic Drug Delivery (ADD) using a nebulizer offers targeted delivery of drug to the sinuses, which may improve the treatment of CRS. This review examines the influence of aerosol particle characteristics, aero-acoustic parameters, inlet flow conditions, and acoustic waves on sinus drug delivery. Key findings reveal that smaller particles improve the ADD efficiency, whereas larger sizes or increased density impair it. The oscillation amplitude of the air plug in the ostium is crucial for the ADD efficiency. Introducing acoustic waves at the NC-sinus system's resonance frequency improves aerosol deposition within sinuses. Future research should address advanced models, optimizing particle characteristics, investigating novel acoustic waveforms, incorporating patient-specific anatomy, and evaluating long-term safety and efficacy. Tackling these challenges, ADD could offer more effective and targeted treatments for sinus-related conditions such as CRS.Oveis Pourmehran, Kavan Zarei, Jeremie Pourchez, Sarah Vreugde, Alkis Psaltis, Peter-John Wormal

Effect of polysaccharides on the hydration of cement suspension

International audienceThis work compares the effects induced by polysaccharides on the hydration of cement. It also brings new insights into the interaction mechanisms between these two components. Several parameters such as structure, concentration, average molecular weight, and the soluble fraction value of the polysaccharides were examined. The hydration of cement was monitored by conductivity measurement, and ionic chromatography. The influence of polysaccharide structure on the kinetics of cement hydration was revealed. The extent of retardation increases when polysaccharide concentration rises. Dextrins with lower average molecular weights compared with starches favor a higher soluble fraction value and further retard hydration. The growth of hydrates seemed to be more affected by the presence of these admixtures than did the dissolution of anhydrous particles or the nucleation of former hydrate

Adsorption at cell surface and cellular uptake of silica nanoparticles with different surface chemical functionalizations: impact on cytotoxicity

International audienceSilica nanoparticles are particularly interesting for medical applications because of the high inertness and chemical stability of silica material. However, at the nanoscale their innocuousness must be carefully verified before clinical use. The aim of this study was to investigate the in vitro biological toxicity of silica nanoparticles depending on their surface chemical functionalization. To that purpose, three kinds of 50 nm fluorescent silica-based nanoparticles were synthesized: 1) sterically stabilized silica nanoparticles coated with neutral polyethylene glycol (PEG) molecules, 2) positively charged silica nanoparticles coated with amine groups and 3) negatively charged silica nanoparticles coated with carboxylic acid groups. RAW 264.7 murine macrophages were incubated for 20 hours with each kind of nanoparticles. Their cellular uptake and adsorption at the cell membrane were assessed by a fluorimetric assay and cellular responses were evaluated in terms of cytotoxicity, pro-inflammatory factor production and oxidative stress. Results showed that the highly positive charged nanoparticle, were the most adsorbed at cell surface and triggered more cytotoxicity than other nanoparticles types. To conclude, this study clearly demonstrated that silica nanoparticles surface functionalization represents a key parameter in their cellular uptake and biological toxicity

Human biological monitoring of nanoparticles, a new way to investigate potential causal links between exposure to nanoparticles and lung diseases?

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Characterization of nicotine salts In E-Liquids and E-Cigarette aerosols.

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Bench-test evaluation of spacer devices for fluticasone delivery to infants

International audienceIntroduction. - Use of a spacer device to optimize the delivery of fluticasone to infants with asthma is an important issue and clinicians require guidance around the choice of device. This in vitro study characterizes the particle size and the fluticasone delivery via 9 spacers. Methods. - We used an in vitro infant nasal cast with two different inspiratory flow rates (50 and 100 mL/s). Fluticasone particle size in the aerosol was evaluated by laser diffractometry and tracheal deposition by spectrophotometric assay. Results. - Significant differences in particle size were observed between the 9 spacers (similar D50 but D90 from 5.65 +/- 0.65 to 8.80 +/- 1.35 mu m). A 75% or higher respirable fraction was obtained for only 5 spacers. The 50 mL/s flow rate lead to the best drug delivery. At this flow, OptiChamber (R) (62 +/- 3 %) and Vortex (R) (91 +/- 8.5%) had a tracheal deposition over 50% of the initial dose of fluticasone, although the 7 other spacers exhibited a fluticasone deposition less than 25%. Discussion. - This study shows a wide variation of drug delivery between the 9 spacers studied. We demonstrate that a low inspiratory flow and a spacer showing antistatic properties facilitate drug delivery. (C) 2016 SPLF. Published by Elsevier Masson SAS. All rights reserved