Bone cements are the subject of intensive research, primarily due to their versatility and the increasing importance for personalized medicine. In this study, novel hybrid self-setting scaffolds, based on calcium phosphates and natural polymers, were fabricated using the robocasting technique. Additionally, the influence of two different silane coupling agents, tetraethyl orthosilicate (TEOS) and 3-glycidoxypropyltrimethoxysilane (GPTMS), on the physicochemical and biological properties of the obtained materials was thoroughly investigated. The chemical and phase compositions (XRF, XRD, FTIR), setting process, rheological properties, mechanical strength, microstructure (SEM), and chemical stability in vitro were comprehensively examined. The use of silane coupling agents improved compressive strength of the scaffolds from 5.20 to 9.26 MPa. The incorporation of citrus pectin into the liquid phase of the materials, along with the use of a hybrid hydroxyapatite-chitosan powder, not only facilitated the development of printable pastes suitable for robocasting but also enhanced the physicochemical properties of the robocasted scaffolds. The results presented in this study underscore the beneficial influence of silane coupling agents on the characteristics of calcium phosphate-based bone scaffolds. Developed robocasted scaffolds hold great potential for applications in the field of bone tissue engineering and personalized medicine. Further in vitro and in vivo studies are necessary to validate their suitability for clinical applications.

• Klíčová slova
• 3d printing, Biopolymers, Hybrid materials, Robocasting, Silane coupling agents, α-TCP,
• MeSH
• biokompatibilní materiály chemie   MeSH
• hydroxyapatit * chemie   MeSH
• mechanické jevy * MeSH
• pevnost v tlaku MeSH
• silany * chemie   MeSH
• testování materiálů * MeSH
• tkáňové podpůrné struktury * chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 3-glycidoxypropyltrimethoxysilane MeSH Prohlížeč
• biokompatibilní materiály MeSH
• hydroxyapatit * MeSH
• silany * MeSH
• tetraethoxysilane MeSH Prohlížeč

Polyurethene (PU) catheters were coated with 3-(trimethoxysilyl)-propyldimethyloctadecylammonium chloride (QAS) by means of a multistep process which involved a vapor phase plasma-induced graft-polymerization of acrylic acid (AAc). The AAc coating, whose stability in aqueous media was assessed by immersion in Phospate Buffer Saline (PBS), was characterized by means of Attenuated Total Reflectance Fourier Transform Infrared (ATR/FTIR) spectroscopy. Moreover, the COOH surface density was evaluated by a colorimetric assay with Methylene Blue. Carrying a negative charge at neutral pH, AAc coatings were proficient in positively charged molecules (like QAS) adsorption. ATR/FTIR spectroscopy and a colorimetric assay with Bromophenol Blue allowed us to verify the presence and the uniformity of the QAS coating on the PU catheters and the positive effect of the AAc graft-polymerization on the QAS adsorption. Morphological characterization of the QAS-modified catheters was performed by means of Atomic Force Microscopy (AFM). QAS-coated catheters displayed in vitro antimicrobial activity against Gram-negative Escherichia coli bacterial cells.

• Klíčová slova
• AFM, ATR/FTIR, Acrylic acid, Escherichia coli, Plasma-induced graft-polymerization, Quaternary ammonium silane,
• MeSH
• akryláty chemie   farmakologie   MeSH
• antibakteriální látky chemie   farmakologie   MeSH
• biokompatibilní potahované materiály chemie   farmakologie   MeSH
• Escherichia coli účinky léků   MeSH
• infekce vyvolané Escherichia coli prevence a kontrola   MeSH
• katétry mikrobiologie   MeSH
• kvartérní amoniové sloučeniny chemie   farmakologie   MeSH
• lidé MeSH
• mikrobiální testy citlivosti MeSH
• polyurethany chemie   farmakologie   MeSH
• povrchové vlastnosti MeSH
• silany chemie   farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• acrylic acid MeSH Prohlížeč
• akryláty MeSH
• antibakteriální látky MeSH
• biokompatibilní potahované materiály MeSH
• kvartérní amoniové sloučeniny MeSH
• polyurethany MeSH
• silany MeSH

Using the SAPT2 + 3(CCD)δMP2 method in complete basis set (CBS) limit, it is shown that the interactions in the recently studied silane⋯carbene dimers are mainly dispersive in nature. Consequently, slow convergence of dispersion energy also forces slow convergence of the interaction energy. Therefore, obtaining very accurate values requires extrapolation of the correlation part to the CBS limit. The most accurate values obtained at the CCSD(T)/CBS level of theory show that the studied silane⋯carbene dimers are rather weakly bound, with interaction energies ranging from about -1.9 to -1.3 kcal/mol. Comparing to CCSD(T)/CBS, it will be shown that SCS-MP2 and MP2C methods clearly underestimate and methods based on SAPT2+ and having some third-order corrections, as well as the MP2 method, overestimate values of interaction energies. Popular SAPT(DFT) method performs better than SCS-MP2 and MP2C; nevertheless, underestimation is still considerable. The underestimation is slightly quenched if third-order dispersion energy and its exchange counterpart is added to the SAPT(DFT). The closest value of CCSD(T)/CBS has been given by the SAPT2 + (3)(CCD)δMP2 method in quadruple-ζ basis set. © 2019 Wiley Periodicals, Inc.

• Klíčová slova
• CCSD(T), SAPT, carbene, dispersion, silane,
• Publikační typ
• časopisecké články MeSH

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

The presented study proposed simple and low-cost approach for improvement in UV protection and superhydrophobic properties of cotton fabrics by coating of mechanically activated fly ash particles. The maximum UV blocking was observed for 3 wt% fly ash, where UV transmittance decreased from 14.19% of untreated fabric to 0.11% of coated fabric. After subsequent treatment of Trimethoxy(octadecyl)silane (OTMS) on fly ash coated fabrics, the water contact angle was increased to 143°, 147° and 153° for fly ash concentration of 1, 2 and 3 wt% respectively. From Cassie-Baxter theories, the unwetted fraction of air pockets were estimated to be 43%, 55% and 67% respectively for 1, 2 and 3 wt% of fly ash particles. Furthermore, the coated fabrics showed great potentials for separation of floating oil layer, underwater oil droplet or oil/water mixture. The separation efficiency of 98%, 96%, 97% and 95% was obtained for selected model oils toluene, n-hexane, chloroform and petro ether, respectively.

• Klíčová slova
• Cotton fabric, Fly ash particles, Oil water separation, Superhydrophobicity, UV protection,
• Publikační typ
• časopisecké články MeSH

The title mol-ecule, [ZrBr(2)(C(12)H(14)Si)], possesses a crystallographically imposed twofold rotational symmetry with the rotation axis passing through the Zr and Si atoms. The Zr(IV) centre is in a distorted tetra-hedral environment defined by two Cp rings of chelating organic ligands and two Br anions. Two five-membered rings form a dihedral angle of 59.7 (2)°. Unequal Zr-C bonds [2.471 (3)-2.556 (3) Å] in the mol-ecule indicate that the inter-action of the central metal with the [(C(5)H(4))(2)SiMe(2)](2-) ligand contains noticeable η(3)-allyl and η(2)-olefin contributions.

• Publikační typ
• časopisecké články MeSH

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

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

Changes in cholesterol concentration in the plasma membrane of presynaptic nerve terminals nonspecifically modulate glutamate transport and homeostasis in the central nervous system. Reduction of the cholesterol content in isolated rat brain nerve terminals (synaptosomes) using cholesterol-depleting agents decreases the glutamate uptake and increases the extracellular level of glutamate in nerve terminals. Extraction of cholesterol from the plasma membrane and its further removal from the synaptosomes by external magnetic field can be achieved by means of magnetic nanoparticles with immobilized cholesterol-depleting agent such as O-methyl-β-cyclodextrin (MCD). A simple approach is developed for preparation of maghemite (γ-Fe2O3) nanoparticles containing chemically bonded MCD. The method is based on preparation of a silanization agent containing MCD. It is synthesized by the reaction of triethoxy(3-isocyanatopropyl)silane with MCD. Base-catalyzed silanization of superparamagnetic γ-Fe2O3 provides a relatively stable colloid product containing 48μmol of MCDg-1. MCD-modified γ-Fe2O3 nanoparticles decrease the initial rate of the uptake and accumulation of l-[14C]glutamate and increase the extracellular l-[14C]glutamate level in the preparation of nerve terminals. The effect of MCD-immobilized nanoparticles is the same as that of MCD solution; moreover, magnetic manipulation of the nanoparticles enables removal of bonded cholesterol.

• Klíčová slova
• Cholesterol, Glutamate, Maghemite nanoparticles, Nerve terminals, O-Methyl-β-cyclodextrin,
• MeSH
• beta-cyklodextriny chemie   farmakologie   MeSH
• biologický transport účinky léků   MeSH
• buněčná membrána účinky léků   metabolismus   MeSH
• cholesterol izolace a purifikace   metabolismus   farmakologie   MeSH
• kinetika MeSH
• krysa rodu Rattus MeSH
• kyselina glutamová metabolismus   MeSH
• magnetické nanočástice chemie   MeSH
• membránové potenciály účinky léků   MeSH
• mozek účinky léků   metabolismus   MeSH
• potkani Wistar MeSH
• presynaptická zakončení účinky léků   metabolismus   MeSH
• radioizotopy uhlíku MeSH
• silany chemie   MeSH
• synaptozomy účinky léků   metabolismus   MeSH
• železité sloučeniny chemie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• beta-cyklodextriny MeSH
• cholesterol MeSH
• ferric oxide MeSH Prohlížeč
• kyselina glutamová MeSH
• magnetické nanočástice MeSH
• methyl-beta-cyclodextrin MeSH Prohlížeč
• radioizotopy uhlíku MeSH
• silany MeSH
• železité sloučeniny MeSH