Pastes and hydrogels from carboxymethyl cellulose sodium salt as supporting electrolyte of solid electrochemical supercapacitors.

Different carboxymethyl cellulose sodium salt (NaCMC)-based pastes and hydrogels, both containing a salt as supporting electrolyte, have been prepared and characterized as potential solid state electrolyte (SSE) for solid electrochemical supercapacitors (ESCs).The characteristics of the NaCMC-based SSEs have been optimized by examining the influence of five different factors in the capacitive response of poly(3,4-ethylenedioxythiophene) (PEDOT) electrodes: i) the chemical nature of the salt used as supporting electrolyte; ii) the concentration of such salt; iii) the concentration of cellulose used to prepare the paste; iv) the concentration of citric acid employed during NaCMC cross-linking; and v) the treatment applied to recover the supporting electrolyte after washing the hydrogel. The specific capacitance of the device prepared using the optimized hydrogel as SSE is 81.5 and 76.8 F/g by means of cyclic voltammetry and galvanostatic charge/discharge, respectively, these values decreasing to 60.7 and 75.5 F/g when the SSE is the paste.

Abediterol (LAS100977), a novel long-acting ß2-agonist: efficacy, safety and tolerability in persistent asthma.

BACKGROUND: Abediterol (LAS100977) is a novel, long-acting ß2-agonist, in development for the once-daily treatment of asthma in combination with mometasone. Here we report the results of a Phase IIa trial of single doses of abediterol added to ongoing maintenance therapy (inhaled corticosteroids) in patients with persistent mild-to-moderate asthma. METHODS: This was a randomised, double-blind, placebo- and active-comparator-controlled, five-way crossover study. Male patients (18-70 years) with a clinical diagnosis of persistent asthma received abediterol (5, 10 and 25 µg), salmeterol and placebo, on top of ongoing maintenance therapy. Lung function was determined using spirometry and whole body plethysmography. The primary efficacy endpoint was change from baseline in trough forced expiratory volume in 1 s (FEV1) after a single dose. RESULTS: All three abediterol doses induced statistically significant increases in trough FEV1 vs placebo and salmeterol. Improvements in other lung function parameters were also statistically significantly greater with all abediterol doses vs both placebo (p < 0.0001) and salmeterol (p < 0.05) than the first assessment at 5 min post-dose. These improvements were sustained to 36 h post-dose. The profile of treatment-emergent adverse events judged as related to abediterol was consistent with that seen after adrenergic stimulation and occurred exclusively in patients who received abediterol 10 µg or 25 µg. CONCLUSIONS: This first-in-patient study revealed the potent, rapid and long-acting bronchodilatory effect of abediterol in patients with persistent mild-to-moderate asthma together with an overall good safety and tolerability profile. Further studies are now underway to establish the optimal efficacy-safety-tolerability profile for this compound.

Lung deposition of aclidinium bromide from Genuair, a multidose dry powder inhaler.

BACKGROUND: Aclidinium bromide is a novel, long-acting inhaled muscarinic antagonist currently in development for the treatment of chronic obstructive pulmonary disease (COPD). A next-generation multidose dry powder inhaler will be used for the delivery of aclidinium bromide. OBJECTIVES: To quantify whole lung deposition and regional lung deposition of aclidinium delivered by a multidose dry powder inhaler (Genuair) in healthy subjects. METHODS: A single dose (200 microg) of aclidinium bromide, radiolabelled with (99m)Tc, was administered from the multidose dry powder inhaler at a targeted peak inspiratory flow rate (PIFR) of 90 litres/min in 12 healthy males (18-63 years). Gamma scintigraphy was used to quantify drug deposition in the lungs and oropharynx, as well as amounts retained in the inhaler and exhaled. The quantities of drug deposited in 6 concentric regions within the lungs were also determined. RESULTS: The mean (+/- SD) PIFR was 79.0 +/- 9.4 litres/min. The mean (+/- SD) percentages of the metered dose deposited in the whole lung and oropharynx were 30.1 +/- 7.3 and 54.7 +/- 7.2%, respectively. Deposition of aclidinium occurred in all 6 lung zones, but was highest in the most central zone. CONCLUSIONS: These results demonstrated that the multidose dry powder inhaler delivered aclidinium efficiently to the lungs. The whole lung deposition seen in this study is an indication of the likely whole lung deposition in COPD patients who inhale with similar PIFRs; however, further studies in patients are required to confirm this.

Ionophore-Phospholipid Interactions in Langmuir Films in Relation to Ionophore Selectivity toward Plasmodium-Infected Erythrocytes.

Carboxylic true ionophores were previously demonstrated to have efficient antimalarial activity against the human parasite Plasmodium falciparum, with a 50% inhibitory concentration around nM and generally high selectivity as compared to their toxic effects against mammalian cell lines. The decreased molecular packing of the erythrocyte membrane outer leaflet after malarial infection could explain the preferential ionophore interaction with infected erythrocytes. Monolayer penetration experiments using different phospholipid films showed strong incorporation of true carboxylic ionophores, from classes 1 (nigericin) and 2 (lasalocid), up to a surface pressure close to film collapse. The interaction was slightly higher with PC (phosphatidylcholine) monolayers than with monolayers composed of cholesterol-containing total lipid extracts from either malaria-infected or normal erythrocytes, and the two latter induced identical interactions with 5-bromo lasalocid. Surface pressure-area isotherms for pure ionophores on water and surface tension of ionophore aqueous solutions clearly highlighted the surface-active characteristics of these ionophores and allowed determination of their molecular area in compact monolayers. The estimated ionophore concentration in the mixed interfacial layers indicates that higher amounts (threefold more) of ionophores might be integrated in infected erythrocyte membrane due to their impaired molecular packing as compared to normal erythrocytes. This infection-enhanced penetration efficiency does not appear directly related to the change in erythrocyte membrane lipid composition, but it could be the basis of ionophore selectivity for infected erythrocytes. Copyright 1999 Academic Press.

Differential in vitro activities of ionophore compounds against Plasmodium falciparum and mammalian cells.

Twenty-two ionophore compounds were screened for their antimalarial activities. They consisted of true ionophores (mobile carriers) and channel-forming quasi-ionophores with different ionic specificities. Eleven of the compounds were found to be extremely efficient inhibitors of Plasmodium falciparum growth in vitro, with 50% inhibitory concentrations of less than 10 ng/ml. Gramicidin D was the most active compound tested, with 50% inhibitory concentration of 0.035 ng/ml. Compounds with identical ionic specificities generally had similar levels of antimalarial activity, and ionophores specific to monovalent cations were the most active. Compounds were further tested to determine their in vitro toxicities against mammalian lymphoblast and macrophage cell lines. Nine of the 22 compounds, i.e., alborixin, lonomycin, nigericin, narasin, monensin and its methylated derivative, lasalocid and its bromo derivative, and gramicidin D, most specific to monovalent cations, were at least 35-fold more active in vitro against P. falciparum than against the two other mammalian cell lines. The enhanced ability to penetrate the erythrocyte membrane after infection could be a factor that determines ionophore selectivity for infected erythrocytes.

Design of a short membrane-destabilizing peptide covalently bound to liposomes.

We characterized the physical and biological properties of a 14-residue amphipathic sequence called SFP (for short fusogenic peptide). At acidic pH, this short synthetic peptide interacts with various phospholipidic monolayers. These interactions were correlated with a pH-dependent conformational transition of SFP resulting in a hydrophobic alpha-helical structure. The hemolysis assay showed a pH-dependent weak membrane destabilizing activity of SFP. However, membrane anchoring of SFP through a covalently bound myristic acid enhanced by 1000-fold its membrane-destabilizing power. Moreover, SFP covalently bound to fluorescent-labeled liposomes induced a pH-dependent mixing of both membranes. SFP, a small synthetic peptide, is thus able to mimick many aspects of viral protein-induced membrane fusion: conformational change, membrane destabilization, membrane anchoring and finally pH-dependent lipid mixing.