Phosphorus-containing heterocyclic cationic surfactants alkyldimethylphenylphospholium bromides with the alkyl chain length 14 to 18 carbon atoms were used for the stabilization of silver nanodispersions. Zeta potential of silver nanodispersions ranges from +35 to +70 mV, which indicates the formation of stable silver nanoparticles (AgNPs). Long-chain heptadecyl and octadecyl homologs of the surfactants series provided the most intensive stabilizing effect to AgNPs, resulting in high positive zeta potential values and smaller diameter of AgNPs in the range 50-60 nm. A comparison with non-heterocyclic alkyltrimethylphosphonium surfactants of the same alkyl chain length showed better stability and more positive zeta potential values for silver nanodispersions stabilized with heterocyclic phospholium surfactants. Investigations of biological activity of phospholium-capped AgNPs are represented by the studies of antimicrobial activity and cytotoxicity. While cytotoxicity results revealed an increased level of HepG2 cell growth inhibition as compared with the cytotoxicity level of silver-free surfactant solutions, no enhanced antimicrobial action of phospholium-capped AgNPs against microbial pathogens was observed. The comparison of cytotoxicity of AgNPs stabilized with various non-heterocyclic ammonium and phosphonium surfactants shows that AgNPs capped with heterocyclic alkyldimethylphenylphospholium and non-heterocyclic triphenyl-substituted phosphonium surfactants have the highest cytotoxicity among silver nanodispersions stabilized by the series of ammonium and phosphonium surfactants.
- Publikační typ
- časopisecké články MeSH
A series of nineteen novel ring-substituted N-arylcinnamanilides was synthesized and characterized. All investigated compounds were tested against Staphylococcus aureus as the reference strain, two clinical isolates of methicillin-resistant S. aureus (MRSA), and Mycobacterium tuberculosis. (2E)-N-[3-Fluoro-4-(trifluoromethyl)phenyl]-3-phenylprop-2-enamide showed even better activity (minimum inhibitory concentration (MIC) 25.9 and 12.9 μM) against MRSA isolates than the commonly used ampicillin (MIC 45.8 μM). The screening of the cell viability was performed using THP1-BlueTM NF-κB cells and, except for (2E)-N-(4-bromo-3-chlorophenyl)-3-phenylprop-2-enamide (IC50 6.5 μM), none of the discussed compounds showed any significant cytotoxic effect up to 20 μM. Moreover, all compounds were tested for their anti-inflammatory potential; several compounds attenuated the lipopolysaccharide-induced NF-κB activation and were more potent than the parental cinnamic acid. The lipophilicity values were specified experimentally as well. In addition, in silico approximation of the lipophilicity values was performed employing a set of free/commercial clogP estimators, corrected afterwards by the corresponding pKa calculated at physiological pH and subsequently cross-compared with the experimental parameters. The similarity-driven property space evaluation of structural analogs was carried out using the principal component analysis, Tanimoto metrics, and Kohonen mapping.
- MeSH
- ampicilin farmakologie MeSH
- analýza hlavních komponent MeSH
- antiflogistika farmakologie MeSH
- cinnamáty chemická syntéza MeSH
- inhibiční koncentrace 50 MeSH
- koncentrace vodíkových iontů MeSH
- lidé MeSH
- methicilin rezistentní Staphylococcus aureus účinky léků MeSH
- mikrobiální testy citlivosti MeSH
- mikrovlny MeSH
- molekulární modely MeSH
- Mycobacterium tuberculosis účinky léků MeSH
- NF-kappa B metabolismus MeSH
- Staphylococcus aureus účinky léků MeSH
- THP-1 buňky MeSH
- viabilita buněk účinky léků MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zánět MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
A series of sixteen ring-substituted N-arylcinnamanilides, previously described as highly antimicrobially effective against a wide spectrum of bacteria and fungi, together with two new derivatives from this group were prepared and characterized. Moreover, the molecular structure of (2E)-N-(2-bromo-5-fluorophenyl)-3-phenylprop-2-enamide as a model compound was determined using single-crystal X-ray analysis. All the compounds were tested for their anti-inflammatory potential, and most tested compounds significantly attenuated the lipopolysaccharide-induced NF-κB activation and were more potent than the parental cinnamic acid. (2E)-N-[2-Chloro-5-(trifluoromethyl)phenyl]-3-phenylprop-2-enamide, (2E)-N-(2,6-dibromophenyl)- 3-phenylprop-2-enamide, and (2E)-N-(2,5-dichlorophenyl)-3-phenylprop-2-enamide demonstrated the highest inhibition effect on transcription factor NF-κB at the concentration of 2 µM and showed a similar effectiveness as the reference drug prednisone. Several compounds also decreased the level of TNF-α. Nevertheless, subsequent tests showed that the investigated compounds affect neither IκBα level nor MAPKs activity, which suggests that the N-arylcinnamanilides may have a different mode of action to prednisone. The modification of the C(2,5)' or C(2,6)' positions of the anilide core by rather lipophilic and bulky moieties seems to be preferable for the anti-inflammatory potential of these compounds.
- MeSH
- antiflogistika chemická syntéza chemie farmakologie MeSH
- cinnamáty chemická syntéza chemie farmakologie MeSH
- krystalografie rentgenová MeSH
- lidé MeSH
- lipopolysacharidy škodlivé účinky MeSH
- molekulární modely MeSH
- molekulární struktura MeSH
- NF-kappa B metabolismus MeSH
- regulace genové exprese účinky léků MeSH
- signální transdukce účinky léků MeSH
- THP-1 buňky MeSH
- TNF-alfa metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The present study is focused on the synthesis and investigation of the physicochemical and biological properties of silver nanoparticles stabilized with a series of cationic gemini surfactants having a polymethylene spacer of variable length. UV-VIS spectroscopy, dynamic light scattering, scanning electron microscopy and zeta potential measurements were applied to provide physicochemical characterization of the silver nanoparticles. The mean size values of the nanoparticles were found to be in the 50 to 115 nm range. From the nanoparticle size distributions and scanning electron microscopy images it results that a population of small nanoparticles with the size of several nanometers was confirmed if the nanoparticles were stabilized with gemini molecules with either a short methylene spacer (two or four -CH₂- groups) or a long spacer (12 -CH₂- groups). The average zeta potential value for silver nanoparticles stabilized with gemini molecules is roughly independent of gemini surfactant spacer length and is approx. +58 mV. An interaction model between silver nanoparticles and gemini molecules which reflects the gained experimental data, is suggested. Microbicidal activity determinations revealed that the silver nanoparticles stabilized with gemini surfactants are more efficient against Gram-negative bacteria and yeasts, which has a direct relation to the interaction mechanism of nanoparticles with the bacterial cell membrane and its structural composition.
Nanoparticles can be considered as a useful tool for improving properties of poorly soluble active ingredients. Hydrochlorothiazide (Class IV of the Biopharmaceutical Classification System) was chosen as a model compound. Antisolvent precipitation-solvent evaporation and emulsion solvent evaporation methods were used for preparation of 18 samples containing hydrochlorothiazide nanoparticles. Water solutions of surfactants sodium dodecyl sulfate, Tween 80 and carboxymethyl dextran were used in mass concentrations of 1%, 3% and 5%. Acetone and dichloromethane were used as solvents of the model compound. The particle size of the prepared samples was measured by dynamic light scattering. The selected sample of hydrochlorothiazide nanoparticles stabilized with carboxymethyl dextran sodium salt with particle size 2.6 nm was characterized additionally by Fourier transform mid-infrared spectroscopy and scanning electron microscopy. It was found that the solubility of this sample was 6.5-fold higher than that of bulk hydrochlorothiazide.
One approach for the enhancement of oral drug bioavailability is the technique of nanoparticle preparation. Risedronate sodium (Biopharmaceutical Classification System Class III) was chosen as a model compound with high water solubility and low intestinal permeability. Eighteen samples of risedronate sodium were prepared by the solvent evaporation technique with sodium dodecyl sulfate, polysorbate, macrogol, sodium carboxymethyl cellulose and sodium carboxymethyl dextran as nanoparticle stabilizers applied in three concentrations. The prepared samples were characterized by dynamic light scattering and scanning electron microscopy. Fourier transform mid-infrared spectroscopy was used for verification of the composition of the samples. The particle size of sixteen samples was less than 200 nm. Polysorbate, sodium carboxymethyl dextran and macrogol were determined as the most favourable excipients; the particle size of the samples of risedronate with these excipients ranged from 2.8 to 10.5 nm.
- MeSH
- biologická dostupnost MeSH
- dextrany chemie MeSH
- diferenciální skenovací kalorimetrie metody MeSH
- dodecylsíran sodný chemie MeSH
- farmaceutická technologie metody MeSH
- kyselina etidronová analogy a deriváty chemie MeSH
- kyselina risedronová MeSH
- mikroskopie elektronová rastrovací metody MeSH
- nanočástice chemie MeSH
- nosiče léků chemie MeSH
- permeabilita MeSH
- polyethylenglykoly chemie MeSH
- polysorbáty chemie MeSH
- pomocné látky chemie MeSH
- rozpouštědla chemie MeSH
- rozpustnost MeSH
- sodná sůl karboxymethylcelulosy chemie MeSH
- velikost částic MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- chemie anorganická MeSH
- dějiny 20. století MeSH
- dějiny 21. století MeSH
- komplexní sloučeniny MeSH
- společnosti farmaceutické MeSH
- významné osobnosti MeSH
- Check Tag
- dějiny 20. století MeSH
- dějiny 21. století MeSH
- Publikační typ
- biografie MeSH
- O autorovi
- Sokolík, Jozef, 1942- Autorita
Cieľom práce bolo vypracovať extrakčnú metódu na stanovenie metadónu a jeho metabolitu EDDP v moči s použitím plynovej chromatografie (GC) vybavenej špecifickým dusíkovým detektorom (NPD). Extrakčná metóda bola optimalizovaná s cieľom získať čo najlepšiu výťažnosť stanovovaných zlúčenín z moču. Optimálne výsledky boli dosiahnuté alkalickou extrakciou (~ pH 9) s dietyléterom, kde ako vnútorný štandard bol použitý proadifén (PA). Stanovená bola výťažnosť extrakcie pre metadón (MTD) 91 ± 5 % a pre jeho metabolit EDDP 86 ± 5 %. Limit detekcie (LOD) pre MTD je 8 ng/ml moču, pre EDDP 23 ng/ml moču a limit kvantifikácie (LOQ) je pre MTD 27 ng/ml moču a pre metabolit EDDP 77 ng/ml moču. Presnosť metódy v rámci jedného dňa sa pohybovala pre MTD v rozmedzí 1,1-2,32 %, pre EDDP 7,3-9,3 % a presnosť metódy v rámci troch dní pre MTD bola 9,1-13,7 %, pre EDDP 4,7-8,7 %.Vhodnosť metódy pre rutinné monitorovanie metadónu a jeho metabolitu EDDP v moči bola overená na 5 vzorkách pacientov zúčastňujúcich sa metadónového udržiavacieho programu.
- MeSH
- chemie bioanorganická MeSH
- farmakologie MeSH
- Publikační typ
- biografie MeSH
- O autorovi
- Krätsmár-Šmogrovič, Juraj, 1926-2011 Autorita
