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

Here, we present a modular synthesis as well as physicochemical and biological evaluation of a new series of amphiphilic dendrons carrying triphenylphosphonium groups at their periphery. Within the series, the size and mutual balance of lipophilic and hydrophilic domains are systematically varied, changing the dendron shape from cylindrical to conical. In physiological solution, the dendrons exhibit very low critical micelle concentrations (2.6-4.9 μM) and form stable and uniform micelles 6-12 nm in diameter, depending on dendron shape; the results correlate well with molecular dynamics simulations. The compounds show relatively high cytotoxicity (IC50 1.2-21.0 μM) associated with micelle formation and inversely related to the size of assembled particles. Depending on their shape, the dendrons show promising results in terms of dendriplex formation and antibacterial activity. In addition to simple amphiphilic dendrons, a fluorescently labeled analogue was also prepared and utilized as an additive visualizing the dendron's cellular uptake.

• MeSH
• antibakteriální látky farmakologie   chemie   chemická syntéza   MeSH
• dendrimery * chemie   chemická syntéza   farmakologie   MeSH
• hydrofobní a hydrofilní interakce MeSH
• lidé MeSH
• micely * MeSH
• organofosforové sloučeniny * chemie   MeSH
• povrchově aktivní látky chemie   chemická syntéza   farmakologie   MeSH
• silany chemie   MeSH
• simulace molekulární dynamiky MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky MeSH
• carbosilane MeSH Prohlížeč
• dendrimery * MeSH
• micely * MeSH
• organofosforové sloučeniny * MeSH
• povrchově aktivní látky MeSH
• silany 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

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

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

The complexity of drug delivery mechanisms calls for the development of new transport system designs. Here, we report a robust synthetic procedure toward stable glycodendrimer (glyco-DDM) series bearing glucose, galactose, and oligo(ethylene glycol)-modified galactose peripheral units. In vitro cytotoxicity assays showed exceptional biocompatibility of the glyco-DDMs. To demonstrate applicability in drug delivery, the anticancer agent doxorubicin (DOX) was encapsulated in the glyco-DDM structure. The anticancer activity of the resulting glyco-DDM/DOX complexes was evaluated on the noncancerous (BJ) and cancerous (MCF-7 and A2780) cell lines, revealing their promising generation- and concentration-dependent effect. The glyco-DDM/DOX complexes show gradual and pH-dependent DOX release profiles. Fluorescence spectra elucidated the encapsulation process. Confocal fluorescence microscopy demonstrated preferential cancer cell internalization of the glyco-DDM/DOX complexes. The conclusions were supported by computer modeling. Overall, our results are consistent with the assumption that novel glyco-DDMs and their drug complexes are very promising in drug delivery and related applications.

• MeSH
• doxorubicin chemie   farmakologie   MeSH
• lékové transportní systémy metody   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• nádory vaječníků * MeSH
• nosiče léků chemie   MeSH
• polyethylenglykoly chemie   MeSH
• protinádorové látky * farmakologie   MeSH
• silany MeSH
• uvolňování léčiv MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• carbosilane MeSH Prohlížeč
• doxorubicin MeSH
• nosiče léků MeSH
• polyethylenglykoly MeSH
• protinádorové látky * MeSH
• silany MeSH

Widely used conazole fungicides (CFs) belong to the most frequently detected pesticides in Central European arable soils. However, data on their environmental behaviour and bioavailability to soil organisms are surprisingly scarce. In the present laboratory microcosm study prochloraz, tebuconazole, epoxiconazole and flusilazole were applied to 12 different agricultural soils at background levels. Bioaccumulation to earthworm E. andrei and lettuce L. sativa roots and leaves was evaluated in non-aged (biota exposure after addition of pesticides) and aged (exposure started three months later) systems. In contrast with expectations from ageing effect (decrease of bioavailability), bioaccumulation in E. andrei was both reduced and enhanced after ageing depending on soil properties. The reduction of bioaccumulation correlated positively to the percentage of clay but negatively to soil organic matter. The affinity of compost worm E. andrei towards organic matter where hydrophobic pesticide molecules are sorbed is discussed as a possible explanation. An apparent effect of ageing (reduction of bioavailability) was particularly observed in lettuce roots, where bioaccumulation was significantly reduced in time. However, bioaccumulation in leaves changed ambiguously in aged variants among CFs, possibly as a combined result of bioconcentration, dilution by plant growth and metabolism. This study brings first insights into how the bioaccumulation of conazole fungicides is affected by sequestration in agricultural soils. The results indicate that in complex systems, the ageing is not necessarily connected with decrease of bioaccumulation.

• Klíčová slova
• Bioavailability, Current-use pesticides, Earthworm, Microcosm, Plant,
• MeSH
• bioakumulace MeSH
• biologická dostupnost MeSH
• epoxidové sloučeniny MeSH
• jíl MeSH
• látky znečišťující půdu analýza   metabolismus   MeSH
• Oligochaeta metabolismus   MeSH
• pesticidy analýza   MeSH
• průmyslové fungicidy analýza   metabolismus   MeSH
• půda chemie   MeSH
• salát (hlávkový) metabolismus   MeSH
• silany MeSH
• triazoly MeSH
• zemědělství MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• epoxiconazole MeSH Prohlížeč
• epoxidové sloučeniny MeSH
• flusilazole MeSH Prohlížeč
• jíl MeSH
• látky znečišťující půdu MeSH
• pesticidy MeSH
• průmyslové fungicidy MeSH
• půda MeSH
• silany MeSH
• tebuconazole MeSH Prohlížeč
• triazoly MeSH

To ensure food safety and to prevent unnecessary foodborne complications this study reports fast, fully automated process for histamine determination. This method is based on magnetic separation of histamine with magnetic particles and quantification by the fluorescence intensity change of MSA modified CdSe Quantum dots. Formation of Fe2O3 particles was followed by adsorption of TiO2 on their surface. Magnetism of developed probe enabled rapid histamine isolation prior to its fluorescence detection. Quantum dots (QDs) of approx. 3 nm were prepared via facile UV irradiation. The fluorescence intensity of CdSe QDs was enhanced upon mixing with magnetically separated histamine, in concentration-dependent manner, with a detection limit of 1.6 μM. The linear calibration curve ranged between 0.07 and 4.5 mM histamine with a low LOD and LOQ of 1.6 μM and 6 μM. The detection efficiency of the method was confirmed by ion exchange chromatography. Moreover, the specificity of the sensor was evaluated and no cross-reactivity from nontarget analytes was observed. This method was successfully applied for the direct analysis of histamine in white wine providing detection limit much lower than the histamine maximum levels established by EU regulation in food samples. The recovery rate was excellent, ranging from 84 to 100% with an RSD of less than 4.0%. The main advantage of the proposed method is full automation of the analytical procedure that reduces the time and cost of the analysis, solvent consumption and sample manipulation, enabling routine analysis of large numbers of samples for histamine and highly accurate and precise results.

• Klíčová slova
• Food safety, Histamine, Ion exchange chromatography, Maghemite, Quantum dots,
• MeSH
• fluorescence MeSH
• fluorescenční barviva chemie   MeSH
• fluorescenční spektrometrie metody   MeSH
• histamin analýza   MeSH
• kontaminace potravin analýza   MeSH
• kovové nanočástice chemie   MeSH
• kvantové tečky chemie   MeSH
• limita detekce MeSH
• magnetické jevy MeSH
• silany chemie   MeSH
• sloučeniny kadmia chemie   MeSH
• telur chemie   MeSH
• titan chemie   MeSH
• víno analýza   MeSH
• železité sloučeniny chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cadmium telluride MeSH Prohlížeč
• ferric oxide MeSH Prohlížeč
• fluorescenční barviva MeSH
• histamin MeSH
• silany MeSH
• sloučeniny kadmia MeSH
• telur MeSH
• tetraethoxysilane MeSH Prohlížeč
• titan MeSH
• titanium dioxide MeSH Prohlížeč
• železité sloučeniny MeSH

Glycodendrimers are a novel group of dendrimers (DDMs) characterized by surface modifications with various types of glycosides. It has been shown previously that such modifications significantly decrease the cytotoxicity of DDMs. Here, we present an investigation of glucose-modified carbosilane DDMs (first-third-generation, DDM1-3Glu) interactions with two models of biological structures: lipid membranes (liposomes) and serum protein (human serum albumin, HSA). The changes in lipid membrane fluidity with increasing concentration of DDMs was monitored by spectrofluorimetry and calorimetry methods. The influence of glycodendrimers on serum protein was investigated by monitoring changes in protein fluorescence intensity (fluorescence quenching) and as protein secondary structure alterations by circular dichroism spectrometry. Generally, all generations of DDMGlu induced a decrease of membrane fluidity and interacted weakly with HSA. Interestingly, in contrast to other dendritic type polymers, the extent of the DDM interaction with both biological models was not related to DDM generation. The most significant interaction with protein was shown in the case of DDM2Glu, whereas DDM1Glu induced the highest number of changes in membrane fluidity. In conclusion, our results suggest that the flexibility of a DDM molecule, as well as its typical structure (hydrophobic interior and hydrophilic surface) along with the formation of larger aggregates of DDM2-3Glu, significantly affect the type and extent of interaction with biological structures.

• Klíčová slova
• Circular dichroism, Differential scanning calorimetry, Glucose-modified carbosilane dendrimers, Liposomes, Membrane fluidity, Model lipid membranes, Proteins,
• MeSH
• cirkulární dichroismus MeSH
• dendrimery chemie   farmakologie   MeSH
• fluidita membrány účinky léků   MeSH
• fluorescenční spektrometrie MeSH
• glukosa chemie   farmakologie   MeSH
• hydrofobní a hydrofilní interakce MeSH
• lidé MeSH
• lidský sérový albumin metabolismus   MeSH
• liposomy MeSH
• nádory farmakoterapie   MeSH
• nosiče léků chemie   farmakologie   MeSH
• protinádorové látky aplikace a dávkování   MeSH
• silany chemie   farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• carbosilane MeSH Prohlížeč
• dendrimery MeSH
• glukosa MeSH
• lidský sérový albumin MeSH
• liposomy MeSH
• nosiče léků MeSH
• protinádorové látky MeSH
• silany 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