Cellulose is a highly versatile and abundant biopolymer that holds significant promise for enhancing capture technologies due to its inherent properties. However, to maximize its effectiveness in carbon dioxide (CO2) adsorption, it is essential to enhance its properties through chemical or physical modifications. By developing cellulose-based materials with tailored functionalities, we can create sustainable sorbents that not only contribute to reducing greenhouse gas emissions but also leverage low-cost and environmentally friendly resources, making them suitable for large-scale applications in carbon capture technologies. This study demonstrates the synthesis of carboxymethyl cellulose-polypyrrole (CMC-PP) nanocomposite and its coating with (3-aminopropyl)triethoxysilane (APTS) or (3-mercaptopropyl)trimethoxysilane (MPTS) to derive CMC-PP-NH2 and CMC-PP-SH nanocomposites, respectively. The designed composites' physicochemical properties were studied using various analytical techniques. The CO2 and N2 capture capabilities of CMC-PP, CMC-PP-NH2, and CMC-PP-SH nanocomposites were investigated. Among them, the CMC-PP-SH nanocomposite has exhibited the highest CO2 adsorption capacity of 49.6 cm3g-1. Adsorption isotherms fitting using the dual-site Langmuir model and calculation of standard enthalpy changes (Qst) reveal that the thiol groups in CMC-PP-SH provide the most favourable interactions for CO2 capture. These findings demonstrate the potential utilization of silane coatings to develop advanced materials for effective gas adsorption and separation technologies.

• Klíčová slova
• CO(2) capture, Carboxymethyl cellulose (CMC), Nanocomposites, Polypyrrole, Silane functionalization,
• Publikační typ
• časopisecké články MeSH

Surface silanols (Si-OH) play a vital role on fused silica surfaces in chromatography. Here, we used an atmospheric-pressure, gas-phase reactor to modify the inner surface of a gas chromatography, fused silica capillary column (0.53 mm ID) with a small, reactive silane (tris(dimethylamino)methylsilane, TDMAMS). The deposition of TDMAMS on planar witness samples around the capillary was confirmed with X-ray photoelectron spectroscopy (XPS), ex situ spectroscopic ellipsometry (SE), and wetting. The number of surface silanols on unmodified and TDMAMS-modified native oxide-terminated silicon were quantified by tagging with dimethylzinc (DMZ) via atomic layer deposition (ALD) and counting the resulting zinc atoms with high sensitivity-low energy ion scattering (HS-LEIS). A bare, clean native oxide - terminated silicon wafer has 3.66 OH/nm2, which agrees with density functional theory (DFT) calculations from the literature. After TDMAMS modification of native oxide-terminated silicon, the number of surface silanols decreases by a factor of ca. 10 (to 0.31 OH/nm2). Intermediate surface testing (IST) was used to characterize the surface activities of functionalized capillaries. It suggested a significant deactivation/passivation of the capillary with some surface silanols remaining; the modified capillary shows significant deactivation compared to the native/unmodified fused silica tubing. We believe that this methodology for determining the number of residual silanols on silanized fused silica will be enabling for chromatography.

• Klíčová slova
• Atomic layer deposition, Capillary column, Dimethylzinc, Fused silica, Low energy ion scattering, Silane, Surface silanol, Tag-and-Count,
• MeSH
• kapiláry MeSH
• křemík * MeSH
• oxid křemičitý MeSH
• oxidy MeSH
• silany * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• křemík * MeSH
• oxid křemičitý MeSH
• oxidy MeSH
• silanol MeSH Prohlížeč
• silany * MeSH

Composite insulation materials are an inseparable part of numerous electrical devices because of synergy effect between their individual parts. One of the main aims of the presented study is an introduction of the dielectric properties of nanoscale magnesium oxide powder via Broadband Dielectric Spectroscopy (BDS). These unique results present the behavior of relative permittivity and loss factor in frequency and temperature range. Following the current trends in the application of inorganic nanofillers, this article is complemented by the study of dielectric properties (dielectric strength, volume resistivity, dissipation factor and relative permittivity) of epoxy-based composites depending on the filler amount (0, 0.5, 0.75, 1 and 1.25 weight percent). These parameters are the most important for the design and development of the insulation systems. The X-ray diffraction patterns are presented for pure resin and resin with optimal filler amount (1 wt %), which was estimated according to measurement results. Magnesium oxide nanoparticles were also treated by addition of silane coupling agent ( γ -Glycidoxypropyltrimethoxysilane), in the case of optimal filler loading (1 wt %) as well. Besides previously mentioned parameters, the effects of surface functionalization have been observed by two unique measurement and evaluation techniques which have never been used for this evaluation, i.e., reduced resorption curves (RRCs) and voltage response method (VR). These methods (developed in our departments), extend the possibilities of measurement of composite dielectric responses related to DC voltage application, allow the facile comparability of different materials and could be used for dispersion level evaluation. This fact has been confirmed by X-ray diffraction analyses.

• Klíčová slova
• broadband dielectric spectroscopy, dielectric strength, loss factor, magnesium oxide, nanocomposite, relative permittivity, surface functionalization, voltage response,
• Publikační typ
• časopisecké články MeSH

Novel synthetic approaches for the development of multimodal imaging agents with high chemical stability are demonstrated. The magnetic cores are based on La0.63Sr0.37MnO3 manganite prepared as individual grains using a flux method followed by additional thermal treatment in a protective silica shell allowing to enhance their magnetic properties. The cores are then isolated and covered de novo with a hybrid silica layer formed through the hydrolysis and polycondensation of tetraethoxysilane and a fluorescent silane synthesized from rhodamine, piperazine spacer, and 3-iodopropyltrimethoxysilane. The aminoalkyltrialkoxysilanes are strictly avoided and the resulting particles are hydrolytically stable and do not release dye. The high colloidal stability of the material and the long durability of the fluorescence are reinforced by an additional silica layer on the surface of the particles. Structural and magnetic studies of the products using XRD, TEM, and SQUID magnetometry confirm the importance of the thermal treatment and demonstrate that no mechanical treatment is required for the flux-synthesized manganite. Detailed cell viability tests show negligible or very low toxicity at concentrations at which excellent labeling is achieved. Predominant localization of nanoparticles in lysosomes is confirmed by immunofluorescence staining. Relaxometric and biological studies suggest that the functionalized nanoparticles are suitable for imaging applications.

• Klíčová slova
• Cell labeling, Dual probes, MRI, Magnetic nanoparticles, Manganites, Molten salt synthesis, Silica coating,
• MeSH
• fibroblasty cytologie   metabolismus   MeSH
• fluorescence MeSH
• fluorescenční protilátková technika MeSH
• HeLa buňky MeSH
• Jurkat buňky MeSH
• kultivované buňky MeSH
• kůže cytologie   metabolismus   MeSH
• lanthan chemie   MeSH
• lidé MeSH
• magnetická rezonanční tomografie MeSH
• magnetické nanočástice chemie   MeSH
• membránové glykoproteiny asociované s lyzozomy imunologie   metabolismus   MeSH
• monoklonální protilátky imunologie   MeSH
• oxid křemičitý chemie   MeSH
• povrchové vlastnosti MeSH
• průtoková cytometrie MeSH
• silany chemie   MeSH
• sloučeniny manganu chemie   MeSH
• stroncium chemie   MeSH
• transmisní elektronová mikroskopie MeSH
• velikost částic MeSH
• viabilita buněk MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• LAMP1 protein, human MeSH Prohlížeč
• lanthan MeSH
• magnetické nanočástice MeSH
• manganite MeSH Prohlížeč
• membránové glykoproteiny asociované s lyzozomy MeSH
• monoklonální protilátky MeSH
• oxid křemičitý MeSH
• silany MeSH
• sloučeniny manganu MeSH
• stroncium MeSH
• tetraethoxysilane MeSH Prohlížeč

Over the last decades, multidrug-resistant bacteria have emerged and spread, increasing the number of bacteria, against which commonly used antibiotics are no longer effective. It has become a serious public health problem whose solution requires medical research in order to explore novel effective antimicrobial molecules. On the one hand, antimicrobial peptides (AMPs) are regarded as good alternatives because of their generally broad-spectrum activities, but sometimes they can be easily degraded by the organism or be toxic to animal cells. On the other hand, cationic carbosilane dendrons, whose focal point can be functionalized in many different ways, have also shown good antimicrobial activity. In this work, we synthetized first- and second-generation cationic carbosilane dendrons with a maleimide molecule on their focal point, enabling their functionalization with three different AMPs. After different microbiology studies, we found an additive effect between first-generation dendron and AMP3 whose study reveals three interesting effects: (i) bacteria aggregation due to AMP3, which could facilitate bacteria detection or even contribute to antibacterial activity by preventing host cell attack, (ii) bacteria disaggregation capability of second-generation cationic dendrons, and (iii) a higher AMP3 aggregation ability when dendrons were added previously to peptide treatment. These compounds and their different effects observed over bacteria constitute an interesting system for further mechanism studies.

• Klíčová slova
• antibacterial peptides, carbosilane dendrons, molecular modeling and molecular dynamics,
• MeSH
• antiinfekční látky chemie   MeSH
• dendrimery chemie   MeSH
• maleimidy chemie   MeSH
• nanokonjugáty chemie   MeSH
• silany chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antiinfekční látky MeSH
• carbosilane MeSH Prohlížeč
• dendrimery MeSH
• maleimide MeSH Prohlížeč
• maleimidy MeSH
• nanokonjugáty MeSH
• silany MeSH

Supramolecular structures, such as micelles, liposomes, polymerosomes or dendrimerosomes, are widely studied and used as drug delivery systems. The behavior of amphiphilic building blocks strongly depends on their spatial distribution and shape of polar and nonpolar component. This report is focused on the development of new versatile synthetic protocols for amphiphilic carbosilane dendrons (amp-CS-DDNs) capable of self-assembly to regular micelles and other supramolecular objects. The presented strategy enables the fine modification of amphiphilic structure in several ways and also enables the facile connection of a desired functionality. DLS experiments demonstrated correlations between structural parameters of amp-CS-DDNs and the size of formed nanoparticles. For detailed information about the organization and spatial distribution of amp-CS-DDNs assemblies, computer simulation models were studied by using molecular dynamics in explicit water.

• Klíčová slova
• DLS, amphiphiles, carbosilane, computer modeling, dendrons, micelles, molecular dynamics, zeta potential,
• MeSH
• anthraceny chemie   MeSH
• hydrofobní a hydrofilní interakce MeSH
• micely MeSH
• nanočástice chemie   MeSH
• počítačová simulace MeSH
• silany chemie   MeSH
• voda chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• anthraceny MeSH
• carbosilane MeSH Prohlížeč
• dendron MeSH Prohlížeč
• micely MeSH
• silany MeSH
• voda MeSH

PURPOSE: The aim was to design and thoroughly characterize monodisperse Fe3O4@SiO2-Ag nanoparticles with strong antibacterial properties, which makes them a candidate for targeting bacterial infections. METHODS: The monodisperse Fe3O4 nanoparticles were prepared by oleic acid-stabilized thermal decomposition of Fe(III) oleate; the particles were coated with silica shell using a water-in-oil reverse microemulsion, involving hydrolysis and condensation of tetramethyl orthosilicate. Resulting Fe3O4@SiO2 particles were modified by (3-mercaptopropyl)trimethoxysilane to introduce 1.1 mmol SH/g. Finally, the Fe3O4@SiO2-SH nanoparticles were decorated with silver nanoclusters formed by reduction of silver nitrate with NaBH4. The particles were analyzed by FTIR, X-ray photoelectron and atomic absorption spectroscopy, dynamic light scattering and vibrating sample magnetometry. The antibacterial activity of the Fe3O4@SiO2 and Fe3O4@SiO2-Ag nanoparticles was tested against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli bacteria cultivated on Luria agar plates or in Luria broth. RESULTS: The superparamagnetic Fe3O4@SiO2-Ag nanoparticles (21 nm in diameter; saturation magnetization 26 A∙m2/kg) were successfully obtained and characterized. Inhibitory and toxic effects against bacteria were documented by incubation of the Fe3O4@SiO2-Ag nanoparticles with Staphylococcus aureus and Escherichia coli. CONCLUSIONS: The combination of magnetic properties together with bactericidal effects is suitable for the disinfection of medical instruments, water purification, food packaging, etc.

• Klíčová slova
• antibacterial activity, magnetic nanoparticles, silica shell, thiol-functionalization,
• MeSH
• antibakteriální látky chemie   farmakologie   MeSH
• Escherichia coli účinky léků   MeSH
• kyselina olejová chemie   MeSH
• magnetické nanočástice chemie   MeSH
• organické sloučeniny křemíku MeSH
• oxid křemičitý chemie   MeSH
• povrchové vlastnosti MeSH
• silany chemie   MeSH
• Staphylococcus aureus účinky léků   MeSH
• stříbro chemie   farmakologie   MeSH
• velikost částic MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• (3-mercaptopropyl)trimethoxysilane MeSH Prohlížeč
• antibakteriální látky MeSH
• kyselina olejová MeSH
• magnetické nanočástice MeSH
• organické sloučeniny křemíku MeSH
• oxid křemičitý MeSH
• silany MeSH
• stříbro MeSH

Amphiphilic dendrons represent a relatively novel class of molecules which may show many unique properties suitable for applications in a field of molecular biology and nanomedicine. They were frequently studied as platforms suitable for drug delivery systems as were, e.g. polymersomes or hybrid lipid-polymer nanoparticles. Recently, natural extracellular lipid vesicles (EVs), called exosomes (EXs), were shown to be a promising candidate in drug delivery applications. Formation of hybrid exosome-dendron nanovesicles could bring benefits in their simple conjugation with selective targeting moieties. Unfortunately, the complex architecture of biological membranes, EXs included, makes obstacles in elucidating the important parameters and mechanisms of interaction with the artificial amphiphilic structures. The aim of the presented work was to study the interaction of two types of amphiphilic carbosilane dendritic structures (denoted as DDN-1 and DDN-2) suitable for further modification with streptavidin (DDN-1) or using click-chemistry approach (DDN-2), with selected neutral and negatively charged lipid model membranes, partially mimicking the basic properties of natural EXs biomembranes. To meet the goal, a number of biophysical methods were used for determination of the degree and mechanisms of the interaction. The results showed that the strength of interactions of amphiphilic dendrons with liposomes was related with surface charge of liposomes. Several steps of interactions were disclosed. The initialization step was mainly coupled with amphiphilic dendrons - liposomes surface interaction resulting in destabilization of large self-assembled amphiphilic dendrons structures. Such destabilization was more significant with liposomes of higher negative charge. With increasing concentration of amphiphilic dendrons in a solution the interactions were taking place also in the hydrophobic part of bilayer. Further increase of nanoparticle concentration resulted in a gradual dendritic cluster formation in a lipid bilayer structure. Due to high affinity of amphiphilic dendrons to model lipid bilayers the conclusion can be drawn that they represent promising platforms also for decoration of exosomes or other kinds of natural lipid vehicles. Such organized hybrid dendron-lipid biomembranes may be advantageous for their subsequent post-functionalization with small molecules, large biomacromolecules or polymers suitable for targeted drug-delivery or theranostic applications.

• Klíčová slova
• Amphiphilic dendrons, Hybrid liposomes, Liposomes, Model membranes, Self-assembling,
• MeSH
• anizotropie MeSH
• dendrimery * chemická syntéza   chemie   MeSH
• kalorimetrie MeSH
• liposomy * chemie   MeSH
• membránové potenciály MeSH
• nanočástice chemie   MeSH
• silany * chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• carbosilane MeSH Prohlížeč
• dendrimery * MeSH
• liposomy * MeSH
• silany * MeSH

Pressure assisted capillary electrophoresis was applied to determination of acid dissociation constants (pKa) of six widely used triazole fungicides (cyproconazole, epoxiconazole, flusilazole, tebuconazole, penconazole and propiconazole) in aqueous medium. The pKa values were determined from the dependence of effective electrophoretic mobility of the triazole fungicides on p[H(+)] of the background electrolyte (BGE) using non-linear regression analysis. The p[H(+)] was used instead of pH to reflect the increased ionic strength of the strongly acidic BGEs (pH<1.75) as compared to the BGEs at pH equal to or greater than 1.75. Prior to the pKa calculation, the measured effective electrophoretic mobilities were corrected to the reference temperature (25°C) and constant ionic strength (25mM). The regression function was modified to allow the determination of pKa in the BGEs of varying ionic strength. The electrophoretic measurements showed that the above triazole fungicides are very weak bases - their pKa values were found to be in the range 1.05-1.97 and were in a good agreement with the values calculated by SPARC online pKa calculator.

• Klíčová slova
• Acid dissociation constant, Capillary electrophoresis, Ionic mobility, Triazole fungicides, pK(a),
• MeSH
• elektroforéza kapilární metody   MeSH
• elektrolyty MeSH
• epoxidové sloučeniny analýza   MeSH
• koncentrace vodíkových iontů MeSH
• osmolární koncentrace MeSH
• průmyslové fungicidy analýza   MeSH
• silany analýza   MeSH
• tlak MeSH
• triazoly analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cyproconazole MeSH Prohlížeč
• elektrolyty MeSH
• epoxiconazole MeSH Prohlížeč
• epoxidové sloučeniny MeSH
• flusilazole MeSH Prohlížeč
• penconazole MeSH Prohlížeč
• propiconazole MeSH Prohlížeč
• průmyslové fungicidy MeSH
• silany MeSH
• tebuconazole MeSH Prohlížeč
• triazoly MeSH

The influence of three generations of five different phosphonium carbosilane dendrimers and one ammonium carbosilane dendrimer as a reference (PMe3, PBu3, P(Et2)2(CH2)3OH, PPh3, P(MeOPh)3 and NMe3, peripheral functional groups) on dimyristoylphosphatidylcholine (DMPC) or a lipid mixture dimyristoylphosphatidylcholine/dimyristoylphosphatidylglycerol (DMPC/DMPG) of liposomes was studied by fluorescence polarization measurements and differential scanning calorimetry. All types of dendrimers interacted with neutral as well as negatively charged liposomes, but the strength and observed influence were different. Concentration, type of peripheral functional group modification and dendrimer generation were the main factors influencing the interaction. Generally, weak interactions as well as destabilization of the lipid membranes at low concentrations, regardless of liposome type, were observed in the case of DmPMe3, DmNMe3, DmPBu3 and DmP(Et2)2(CH2)3OH. Dendrimers with PPh3 and P(MeOPh)3 peripheral functional groups interacted much more strongly and increased the rigidity of liposomes. Electrostatic interactions, the hydrophobicity of substituents and charge shielding on the peripheral phosphonium group are important factors in the interaction. We suggest that, among the other types of dendrimers, the dendrimer with the P(MeOPh)3 peripheral functional group is a highly promising candidate for the design of a drug delivery system due to its positive charge, efficient interaction with lipidic membranes and low cytotoxicity.

• MeSH
• dendrimery chemie   MeSH
• glycerofosfolipidy chemie   MeSH
• hydrofobní a hydrofilní interakce MeSH
• lipidové dvojvrstvy chemie   MeSH
• liposomy chemie   MeSH
• molekulární struktura MeSH
• povrchové vlastnosti MeSH
• silany chemie   MeSH
• statická elektřina MeSH
• velikost částic MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• carbosilane MeSH Prohlížeč
• dendrimery MeSH
• glycerofosfolipidy MeSH
• lipidové dvojvrstvy MeSH
• liposomy MeSH
• silany MeSH