Rapid progress in the development of highly efficient nanoparticle-based construction technologies has not always been accompanied by a corresponding understanding of their effects on human health and ecosystems. In this study, we compare the toxicological effects of pristine TiO2, ZnO, SiO2, and coated SiO2 nanoparticles, and evaluate their suitability as additives to consolidants of weathered construction materials. First, water soluble tetrazolium 1 (WST-1) and lactate dehydrogenase (LDH) assays were used to determine the viability of human alveolar A549 cells at various nanoparticle concentrations (0-250 μg mL-1). While the pristine TiO2 and coated SiO2 nanoparticles did not exhibit any cytotoxic effects up to the highest tested concentration, the pristine SiO2 and ZnO nanoparticles significantly reduced cell viability. Second, as all developed nanoparticle-modified consolidants increased the mechanical strength of weathered sandstone, the decisive criterion for the selection of the most suitable nanoparticle additive was as low toxicity as possible. We believe that this approach would be of high importance in the industry, to identify materials representing top functional properties and low toxicity, at an early stage of the product development.

• Klíčová slova
• SiO2 nanoparticles, TiO2 nanoparticles, ZnO nanoparticles, ethyl silicate consolidants, toxicity,
• Publikační typ
• časopisecké články MeSH

The development of hybrid nanoscintillators is hunted for the implementation of modern detection technologies, like in high energy physics, homeland security, radioactive gas sensing, and medical imaging, as well as of the established therapies in radiation oncology, such as in X-ray activated photodynamic therapy. Engineering of the physico-chemical properties of nanoparticles (NPs) enables the manufacture of hybrids in which the conjugation of inorganic/organic components leads to increased multifunctionality and performance. However, the optimization of the properties of nanoparticles in combination with the use of ionizing radiation is not trivial: a complete knowledge on the structure, composition, physico-chemical features, and scintillation property relationships in hybrid nanomaterials is pivotal for any applications exploiting X-rays. In this paper, the design of hybrid nanoscintillators based on ZnO grown onto porous SiO2 substrates (ZnO/SiO2) has been performed in the view to create nanosystems potentially suitable in X-ray activated photodynamic therapy. Indeed, cytotoxic porphyrin dyes with increasing concentrations have been anchored on ZnO/SiO2 nanoparticles through amino-silane moieties. Chemical and structural analyses correlated with photoluminescence reveal that radiative energy transfer between ZnO and porphyrins is the principal mechanism prompting the excitation of photosensitizers. The use of soft X-ray excitation results in a further sensitization of the porphyrin emission, due to augmented energy deposition promoted by ZnO in the surroundings of the chemically bound porphyrin. This finding unveils the cruciality of the design of hybrid nanoparticles in ruling the efficacy of the interaction between ionizing radiation and inorganic/organic moieties, and thus of the final nanomaterial performances towards the foreseen application.

• MeSH
• luminiscence MeSH
• nanočástice * chemie   MeSH
• oxid křemičitý chemie   MeSH
• oxid zinečnatý * chemie   MeSH
• porfyriny * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• oxid křemičitý MeSH
• oxid zinečnatý * MeSH
• porfyriny * MeSH

Silicon dioxide, in the form of nanoparticles, possesses unique physicochemical properties (size, shape, and a large surface to volume ratio). Therefore, it is one of the most promising materials used in biomedicine. In this paper, we compare the biological effects of both mesoporous silica nanoparticles extracted from Urtica dioica L. and pyrogenic material. Both SEM and TEM investigations confirmed the size range of tested nanoparticles was between 6 and 20 nanometers and their amorphous structure. The cytotoxic activity of the compounds and intracellular ROS were determined in relation to cells HMEC-1 and erythrocytes. The cytotoxic effects of SiO2 NPs were determined after exposure to different concentrations and three periods of incubation. The same effects for endothelial cells were tested under the same range of concentrations but after 2 and 24 h of exposure to erythrocytes. The cell viability was measured using spectrophotometric and fluorimetric assays, and the impact of the nanoparticles on the level of intracellular ROS. The obtained results indicated that bioSiO2 NPs, present higher toxicity than pyrogenic NPs and have a higher influence on ROS production. Mesoporous silica nanoparticles show good hemocompatibility but after a 24 h incubation of erythrocytes with silica, the increase in hemolysis process, the decrease in osmotic resistance of red blood cells, and shape of erythrocytes changed were observed.

• Klíčová slova
• biogenic and pyrogenic silicon dioxide, cytotoxicity, mesoporous silica, nanoparticles,
• MeSH
• endoteliální buňky účinky léků   MeSH
• erytrocyty účinky léků   MeSH
• hemolýza účinky léků   MeSH
• lidé MeSH
• nanočástice aplikace a dávkování   chemie   MeSH
• oxid křemičitý aplikace a dávkování   chemie   MeSH
• oxidační stres účinky léků   MeSH
• poréznost MeSH
• povrchové vlastnosti MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• viabilita buněk MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• oxid křemičitý MeSH
• reaktivní formy kyslíku MeSH

Nanoparticles are extremely promising components that are used in diagnostics and medical therapies. Among them, silica nanoparticles are ultrafine materials that, due to their unique physicochemical properties, have already been used in biomedicine, for instance, in cancer therapy. The aim of this study was to investigate the cytotoxicity of three types of nanoparticles (SiO2, SiO2-SH, and SiO2-COOH) in relation to red blood cells, as well as the impact of silicon dioxide nanoparticles on biological membranes and liposome models of membranes. The results obtained prove that hemolytic toxicity depends on the concentration of nanoparticles and the incubation period. Silica nanoparticles have a marginal impact on the changes in the osmotic resistance of erythrocytes, except for SiO2-COOH, which, similarly to SiO2 and SiO2-SH, changes the shape of erythrocytes from discocytes mainly towards echinocytes. What is more, nanosilica has an impact on the change in fluidity of biological and model membranes. The research gives a new view of the practical possibilities for the use of large-grain nanoparticles in biomedicine.

• Klíčová slova
• biological membranes, erythrocyte membranes, erythrocytes, hemolytic toxicity, liposomes, osmotic resistance, silica nanoparticles,
• MeSH
• buněčná membrána MeSH
• erytrocyty MeSH
• membrány MeSH
• nanočástice * chemie   MeSH
• oxid křemičitý * chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• oxid křemičitý * MeSH

It is crucial to fabricate cost-effective and efficient strategies for monitoring and eliminating hazardous metals in the water supplies. Among the many techniques, adsorption is one of the most powerful and facile ways for eliminating pollutants from effluents. It is also crucial to engineering high-performance low-cost adsorbents. In this regard, herein, Fe3O4@SiO2@(BuSO3H)3 as a modified core-shell magnetic silica nanoparticle embodies good selectivity to extract toxic metal ions from aquatic media. The present work investigated the removal performance of the magnetic adsorbent towards Pd2+ cation amongst the other heavy metal ions including Co2+, Pb2+, Hg2+, Cd2+, Cu2+, Zn2+ in aqueous solution. The flame atomic absorption spectrometry (FAAS) was utilized to assess the removal efficiency of the adsorbent. Several experimental parameters including elution condition, initial Pd(II) concentration, adsorbent dosage, initial pH of the solution, and contact time were explored to achieve the optimal conditions. The data of adsorption were very well with the Langmuir isotherm model, according to the adsorption isotherm mechanism experiments. In conclusion, this study lays the way for the development of novel magnetic adsorbents with high removal efficiencies for the removal of toxic metal ions from aqueous environment.

• Klíčová slova
• Adsorption, Flame atomic absorption spectrometry (FAAS), Magnetic nanoparticles, Metal extraction, Pd(2+) ion,
• MeSH
• adsorpce MeSH
• chemické látky znečišťující vodu * analýza   MeSH
• ionty MeSH
• kadmium analýza   MeSH
• kinetika MeSH
• koncentrace vodíkových iontů MeSH
• magnetické nanočástice * MeSH
• olovo MeSH
• oxid křemičitý MeSH
• rtuť * analýza   MeSH
• těžké kovy * analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• odvolaná publikace MeSH
• Názvy látek
• chemické látky znečišťující vodu * MeSH
• ionty MeSH
• kadmium MeSH
• magnetické nanočástice * MeSH
• olovo MeSH
• oxid křemičitý MeSH
• rtuť * MeSH
• těžké kovy * MeSH

The Letter describes the preparation and characterization of a conjugate of isoniazid (INH) with magnetic nanoparticles Fe3O4@SiO2 115±60 nm in size. The INH molecules were attached to the surface of nanoparticles by a covalent pH-sensitive amidine bond. The conjugate was characterized by X-ray diffraction, SEM, dynamic light scattering, IR spectroscopy and microanalysis. The conjugate released isoniazid under in vitro conditions (pH=4; 37 °C; t1/2≈115 s). In addition, the cytotoxicity of the Fe3O4@SiO2-INH conjugate was evaluated in SK-BR-3 cells using the xCELLigence system.

• Klíčová slova
• Isoniazid, Magnetic nanoparticle, Prodrug, Tuberculostatic agent, pH-sensitivity,
• MeSH
• antibakteriální látky chemická syntéza   chemie   toxicita   MeSH
• difrakce rentgenového záření MeSH
• isoniazid chemická syntéza   chemie   toxicita   MeSH
• koncentrace vodíkových iontů MeSH
• kultivované buňky MeSH
• magnetismus * MeSH
• mikroskopie elektronová rastrovací MeSH
• nanočástice chemie   MeSH
• oxid křemičitý chemie   MeSH
• proliferace buněk účinky léků   MeSH
• železité sloučeniny chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antibakteriální látky MeSH
• ferric oxide MeSH Prohlížeč
• isoniazid MeSH
• oxid křemičitý MeSH
• železité sloučeniny MeSH

The widespread use of silica nanoparticles (SiO2-NPs) in various industries, including chemical polishing, cosmetics, varnishes, medical, and food products, has increased the risk of their release into aquatic ecosystems. The toxic effects of small-size SiO2-NPs on the reproductive performance of zebrafish (Danio rerio) have yet to be widely studied. This study aimed to investigate the impact of chronic exposure to small-sized (35 ± 6 nm) SiO2-NPs on adult zebrafish through waterborne exposure to concentrations of 5 (SNP5), 10 (SNP10), 15 (SNP15), and 20 (SNP20) μg/L of SiO2-NPs for 28 days. Our results showed that SiO2-NPs significantly impacted several biochemical parameters, including cholesterol, triglycerides, LDL, HDL, total protein, albumin, urea levels, and alkaline phosphatase and aspartate aminotransferase activity. Cortisol and glucose levels in the SNP20 group significantly differed from the control group. All the exposed groups, apart from SNP5, experienced a significant increase in their total immunoglobulin levels and lysozyme activity. While there was a considerable increase in the activity of catalase and superoxide dismutase in all exposed groups, the expression of antioxidant genes did not appear to be affected. Furthermore, the expression level of il8 was significantly higher in SNP5 and SNP10 than in other treatments. Exposure to SiO2-NPs caused a decrease in gonad weight, absolute fecundity, and larval survival rate, particularly in the SNP20 group. The present study indicates that SiO2-NPs can harm zebrafish and thus further research is necessary to assess their health and environmental risks.

• Klíčová slova
• Environmental risks, Gene expression, Nanotoxicology, Reproductive toxicity, Silica nanoparticles,
• MeSH
• dánio pruhované * MeSH
• ekosystém MeSH
• nanočástice * toxicita   MeSH
• oxid křemičitý toxicita   MeSH
• oxidační stres MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• oxid křemičitý MeSH

The reaction time, temperature, ratio of precursors, and concentration of sodium citrate are known as the main factors that affect the direct synthesis process of SiO2@Au based on the chemical reaction of HAuCl4 and sodium citrate. Hence, we investigated, in detail, and observed that these factors played a crucial role in determining the shape and size of synthesized nanoparticles. The significant enhancement of the SERS signal corresponding to the fabrication conditions is an existing challenge. Our study results show that the optimal reaction conditions for the fabrication of SiO2@Au are a 1:21 ratio of HAuCl4 to sodium citrate, with an initial concentration of sodium citrate of 4.2 mM, and a reaction time lasting longer than 6 h at a temperature of 80 °C. Under optimal conditions, our synthesis process result is SiO2@Au nanoparticles with a diameter of approximately 350 nm. In particular, the considerable enhancement of Raman intensities of SiO2@Au compared to SiO2 particles was examined.

• Klíčová slova
• Raman spectroscopy, SERS, SiO2@Au, core shell,
• Publikační typ
• časopisecké články MeSH

Herein, we investigated the influence of two types of nanoparticle fillers, i.e., amorphous SiO2 and crystalline ZrO2, on the structural properties of their nanocomposites with high-density polyethylene (HDPE). The composite films were prepared by melt-blending with a filler content that varied from 1% to 20% v/v. The composites were characterized by small- and wide-angle x-ray scattering (SAXS and WAXS), small-angle neutron scattering (SANS), Raman spectroscopy, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). For both fillers, the nanoaggregates were evenly distributed in the polymer matrix and their initial state in the powders determined their surface roughness and fractal character. In the case of the nano-ZrO2 filler, the lamellar thickness and crystallinity degree remain unchanged over a broad range of filler concentrations. SANS and SEM investigation showed poor interfacial adhesion and the presence of voids in the interfacial region. Temperature-programmed SANS investigations showed that at elevated temperatures, these voids become filled due to the flipping motions of polymer chains. The effect was accompanied by a partial aggregation of the filler. For nano-SiO2 filler, the lamellar thickness and the degree of crystallinity increased with increasing the filler loading. SAXS measurements show that the ordering of the lamellae is disrupted even at a filler content of only a few percent. SEM images confirmed good interfacial adhesion and integrity of the SiO2/HDPE composite. This markedly different impact of both fillers on the composite structure is discussed in terms of nanoparticle surface properties and their affinity to the HDPE matrix.

• Klíčová slova
• SANS, SAXS, fractal, interface, lamellar thickness, polymer-matrix nanocomposite,
• Publikační typ
• časopisecké články MeSH

Starting NaYF4:Yb(3+)/Er(3+) nanoparticles with size tuned from 24 to 33 nm were prepared by high-temperature coprecipitation of lanthanide chlorides in high-boiling organic solvents. To enhance colloidal stability in aqueous medium, an aminosilica shell was introduced on the surface by hydrolysis and condensation of tetramethyl orthosilicate and (3-aminopropyl)trimethoxysilane using a reverse microemulsion technique; to form alkyne groups, reaction with 4-pentynoic acid followed. Finally, the cell adhesive and cell penetrating azidopentanoyl-GGGRGDSGGGY-NH2 (RGDS) and azidopentanoyl-GGGRKKRRQRRR-NH2 (TAT) peptides were conjugated to the upconversion particles via Cu(I)-catalyzed alkyne-azide cycloaddition. The concentrations of the peptides bound to the nanoparticle surfaces and amount of adsorbed residual Cu(I) catalyst were determined using an (125)I-radiolabeled RGDS peptide and a (64)Cu(I)-doped catalyst, respectively. Targeting and uptake of the RGDS- and TAT-conjugated NaYF4:Yb(3+)/Er(3+)&SiO2 nanoparticles by human cervix carcinoma HeLa cells were monitored by confocal microscopy. RGDS-conjugated nanoparticle probes were mainly localized on the cell plasma membrane due to specific binding of the peptide to the corresponding integrins. In contrast, the TAT-conjugated nanoparticles were able to cross the cell membrane and accumulate in the cell cytoplasm. Thus, this new peptide bioconjugation approach supported both extra- and intracellular nanoparticle uptake, enabling targeting and imaging of the specific tumor phenotypes.

• Klíčová slova
• HeLa cells, RGDS peptide, TAT peptide, nanoparticles, upconversion,
• Publikační typ
• časopisecké články MeSH