titanium dioxide (TiO2)
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The photocatalytic reduction of CO2 with H2O was investigated using Cu/TiO2 photocatalysts in aqueous solution. For this purpose, Cu/TiO2 photocatalysts (with 0.2, 0.9, 2, 4, and 6 wt.% of Cu) have been synthesized via sol-gel method. The photocatalysts were extensively characterized by means of inductively coupled plasma optical emission spectrometry (ICP-OES), N2 physisorption (BET), XRD, UV-vis DRS, FT-IR, Raman spectroscopy, TEM-EDX, and photoelectrochemical measurements. The as-prepared photocatalysts contain anatase as a major crystalline phase with a crystallite size around 13 nm. By increasing the amount of Cu, specific surface area and band gap energy decreased in addition to the formation of large agglomeration of CuO. Results revealed that the photocatalytic reduction of CO2 decreased in the presence of Cu/TiO2 in comparison to pure TiO2, which might be associated to the formation of CuO phase acting as a recombination center of generated electron-hole pair. Decreasing of photoactivity can also be connected with a very low position of conduction band of photocatalysts with high Cu content, which makes H2 production necessary for CO2 reduction more difficult.
Titanium dioxide (TiO2) and Ag-incorporated diamond-like carbon (DLC) films were prepared on different substrates. The films were prepared by pulsed laser deposition (PLD). TiO2 and Ag were selected due to their potential values as biomaterials. Silver is effective against a wide range of spectrum including Gram-negative and Gram-positive bacteria and yeast. TiO2 and Ag-incorporated DLC thin films are suitable candidates for application on biomedical devices and implants due to their biocompatibility, chemical inertness, and mechanical properties. Thin films are widely used in coronary artery stents, dental implants, heart valves and other vascular devices. The microstructure and antibacterial properties of TiO2 and silver-doped diamond-like carbon (DLC) films have been investigated. The films structural quality was evaluated using SEM microscopy, AFM microscopy and Raman spectroscopy. The antibacterial activity was determined using Gram-negative bacteria Escherichia coli and Gram-positive bacteria Bacillus subtilis. Our results demonstrate that the TiO2, nitrogen doped titanium oxides TON and Ag-incorporated DLC films are potentially useful as biomedical materials having good antibacterial properties.
Anthracyclines are a class of pharmaceuticals used in cancer treatment have the potential to negatively impact the environment. To study the possibilities of anthracyclines (represented by pirarubicin and valrubicin) removal, chemical inactivation using NaOH (0.01 M) and NaClO (5%) as decontamination agents and adsorption to powdered nanocrystalline titanium dioxide (TiO2) were compared. The titanium dioxide (TiO2) nanoparticles were prepared via homogeneous precipitation of an aqueous solution of titanium (IV) oxy-sulfate (TiOSO4) at different amount (5-120 g) with urea. The as-prepared TiO2 samples were characterized by XRD, HRSEM and nitrogen physisorption. The adsorption process of anthracycline cytostatics was determined followed by high-performance liquid chromatography coupled with mass spectrometry (LC-MS) and an in-situ Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) technique. It was found that NaClO decomposes anthracyclines to form various transformation products (TPs). No TPs were identified after the reaction of valrubicin with a NaOH solution as well as in the presence of TiO2 nanoparticles. The best degree of removal, 100% of pirarubicin and 85% of valrubicin, has been achieved in a sample with 120 grams of TiOSO4 (TIT120) and TiO2 with 60 grams (TIT60), respectively.
- MeSH
- adsorpce MeSH
- chemické látky znečišťující vodu chemie izolace a purifikace MeSH
- chlornan sodný chemie MeSH
- cytostatické látky chemie izolace a purifikace MeSH
- dekontaminace metody MeSH
- doxorubicin analogy a deriváty chemie izolace a purifikace MeSH
- hydrolýza MeSH
- hydroxid sodný chemie MeSH
- krystalizace MeSH
- nanostruktury chemie MeSH
- povrchové vlastnosti MeSH
- titan chemie MeSH
- velikost částic MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
The aim of present study was to assess the toxicological effects of transition metal-doped titanium dioxide nanoparticles (TiO2 NPs) on histopathological changes, behavioral patterns, and antioxidant responses of goldfish (Carassius auratus) and common carp (Cyprinus carpio). The synthesized nanoparticles were confirmed by Transmission Electron Microscopy, Field Emission Scanning Electron Microscopy, X-ray diffraction, UV-visible, and Vibration Sample Magnetometer. Fish in four experimental groups exposed to sub-lethal concentrations of pure TiO2 NPs (10 mg L-1), chromium (Cr), iron (Fe), and nickel (Ni) doped TiO2 NPs for seven days. Statistical analysis of oxidative stress responses in gills showed significant differences in superoxide dismutase, total antioxidant capacity, and malondialdehyde parameters between two species and in all parameters than glutathione peroxidase between experimental groups and control group. In intestine, no significant difference was observed among groups, but oxidative responses were markedly different in all parameters among fish species. The histopathological analysis showed hyperplasia, fusion, and aneurism in the gills as well as degeneration, integration of villi, necrosis and erosion of the intestine. Our findings indicated that compare to pure TiO2 NPs, exposure to transition metals-doped TiO2 NPs induced oxidative stress and histopathological changes in both fish species.
The aim of the study was the comparison of photo-activity of three types of titanium dioxide (TiO2) micro-dispersions intended for use as UV filters for cosmetic sunscreen products. The dispersions were also investigated with regard to their influence on the stability of photo-protective systems in cosmetic emulsions, their skin penetration/absorption and their photo-toxicity for humans and skin bacterial flora. All the tested micro-dispersions of rutile TiO2 type (agglomerates with diameter 120-150 nm), with primary particle size lower than 100 nm, demonstrated no phototoxic effect and insignificant antimicrobial behaviour. On the other hand, TiO2 with insufficient deactivation of photo-activity had significant negative impact on the stability of other organic UV filters and therefore on the stability of declared UV protective factors (SPF, UVA-PF). The study demonstrated that the level of deactivation of TiO2 is one of the highly important factors for evaluation of UV filters used as sunscreens.
- MeSH
- antibakteriální látky * chemie farmakologie účinky záření MeSH
- azosloučeniny chemie MeSH
- barvicí látky chemie MeSH
- benzensulfonáty chemie MeSH
- buňky 3T3 MeSH
- Escherichia coli účinky léků MeSH
- farmaceutická chemie MeSH
- kožní absorpce MeSH
- kůže metabolismus MeSH
- kyselina askorbová chemie MeSH
- myristáty chemie MeSH
- myši MeSH
- nanočástice * chemie účinky záření MeSH
- prasata MeSH
- přípravky chránící proti slunci * chemie farmakologie účinky záření MeSH
- Staphylococcus epidermidis účinky léků MeSH
- techniky in vitro MeSH
- titan * chemie farmakologie účinky záření MeSH
- ultrafialové záření MeSH
- velikost částic MeSH
- voda chemie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Nanoparticular form of titanium dioxide (TiO2 NPs) belongs to important industrial material. Despite being widely used, serious contradictions regarding biosafety of TiO2 NPs remain. We anticipate that such discrepancies could be due to a lack of understanding of a linkage between TiO2 NPs phase composition and cytotoxicity. Therefore, we synthesized two types of biphasic TiO2 NPs differing in an anatase-brookite phase composition. The study presents an array of in vitro data suggesting that TiO2 NPs with a prevailing anatase phase composition possess higher cytotoxicity compared to TiO2 NPs with an equal anatase-brookite crystallinity. This phenomenon was evidenced by significantly higher inhibition of metabolic activity and growth of epithelial and neuroblast-like cells. Moreover, anatase-prevailing TiO2 NPs tend to produce higher amount of reactive oxygen species resulting in DNA fragmentation. Further insights into the molecular aspects of cytotoxicity of anatase-prevailing TiO2 NPs were obtained by comparative proteomics delineating that TiO2 NPs deregulate expression of a variety of proteins and associated pathways. This inevitably results in a decreased cellular ability to detoxify reactive oxygen species and respond to various stress conditions. The study provides novel data that add another piece to the jigsaw of the relation between structural features of NPs and biosafety.
- MeSH
- buněčné linie MeSH
- epitelové buňky účinky léků metabolismus MeSH
- kovové nanočástice chemie toxicita ultrastruktura MeSH
- krystalografie rentgenová MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- oxidační stres * MeSH
- reaktivní formy kyslíku metabolismus MeSH
- titan chemie toxicita MeSH
- transmisní elektronová mikroskopie MeSH
- viabilita buněk účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Nowadays, titanium and its alloys are the most commonly used implantable materials. The surface topography and chemistry of titanium-based implants are responsible for osseointegration. One of the methods to improve biocompatibility of Ti implants is a modification with sodium hydroxide (NaOH) or 3-aminopropyltriethoxysilane (APTES). In the present study, anodic titanium dioxide (ATO) layers were electrochemically fabricated, and then immersed in a NaOH solution or in NaOH and APTES solutions. The functionalized samples were characterized by using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). All samples were examined as drug delivery systems and scaffolds for cell culturing. Based on the parameters of the fitted desorption-desorption-diffusion (DDD) model parameters, it was concluded that the modification with NaOH increased the amount of released ibuprofen and inhibited the release process. Osteoblast-like cell line (SAOS-2) was used to investigate the cell response on the non-modified and modified ATO samples. The MTS test and immunofluorescent staining were carried out to examine cell adhesion and proliferation. The data showed that the modification of nanoporous TiO2 layers with small molecules such as APTES enhanced metabolic activity of adhered cells compared with the non-modified and NaOH-modified TiO2 layers. In addition, the cells had a polygonal-like morphology with distinct projecting actin filaments and were well dispersed over the whole analyzed surface.
- MeSH
- buněčná adheze účinky léků MeSH
- buněčné linie MeSH
- elektrochemické techniky MeSH
- elektrody MeSH
- hydroxid sodný chemie MeSH
- lékové transportní systémy * MeSH
- lidé MeSH
- osteoblasty cytologie účinky léků MeSH
- poréznost MeSH
- povrchové vlastnosti MeSH
- proliferace buněk účinky léků MeSH
- propylaminy chemie MeSH
- silany chemie MeSH
- titan chemie MeSH
- velikost částic MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Commercially manufactured nanomaterials are used massively for modification of products of everyday use, including products intended for children. Therefore their potential risks have to be ultimately studied. Aside from toxicity of nanomaterials with known specific parameters, the end-consumer is potentially endangered by materials with unknown specification. Commercially available products are not usually accompanied by parameter/specification sheet providing the consumer with sufficient chemico-physical parameters allowing the evaluation of possible toxic effects. The aim of this work was to evaluate the declared parameters of commercially available TiO2 and Ag NPs employing chemico-physical methods and consequently in vitro cytotoxicity and genotoxicity tests performed on non-cancer cell lines. Based on the results of our complex study we can conclude that the data provided by the producers are not in good agreement with the performed measurements. Furthermore, all tested NPs penetrated into the SVK14 cells and all NPs had significant effect on the kinetics of ROS production in all cell lines (note: the ROS production has not been established as the major mechanism of cell damage elicited by Ag NPs). The study revealed greater cytotoxic potential of Ag NPs in comparison with TiO2 NPs and all of the studied NPs caused significant DNA damage.
- MeSH
- apoptóza účinky léků MeSH
- buněčné linie účinky léků metabolismus MeSH
- buňky NIH 3T3 účinky léků MeSH
- kometový test MeSH
- kovové nanočástice chemie toxicita MeSH
- lidé MeSH
- membránový potenciál mitochondrií účinky léků MeSH
- mikroskopie atomárních sil MeSH
- myši MeSH
- Ramanova spektroskopie MeSH
- reaktivní formy kyslíku metabolismus MeSH
- spektrofotometrie atomová MeSH
- stříbro chemie farmakokinetika toxicita MeSH
- titan farmakokinetika toxicita MeSH
- velikost částic MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Hydrogel based matrices and titanium dioxide (TiO2) nanoparticles (NPs) are well established materials in bone tissue engineering. Nevertheless, there is still a challenge to design appropriate composites with enhanced mechanical properties and improved cell growth. Progressing in this direction, we synthesized nanocomposite hydrogels by impregnating TiO2 NPs in a chitosan and cellulose-based hydrogel matrix containing polyvinyl alcohol (PVA), to enhance the mechanical stability and swelling capacity. Although, TiO2 has been incorporated into single and double component matrix systems, it has rarely been combined with a tri-component hydrogel matrix system. The doping of NPs was confirmed by Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy and small- and wide-angle X-ray scattering. Our results showed that incorporation of TiO2 NPs improved the tensile properties of the hydrogels significantly. Furthermore, we performed biological evaluation of scaffolds, swelling degree, bioactivity assessment, and hemolytic tests to prove that all types of hydrogels were safe for use in the human body. The culturing of human osteoblast-like cells MG-63 on hydrogels showed better adhesion of cells in the presence of TiO2 and showed increasing proliferation with increasing amount of TiO2. Our results showed that the sample with the highest TiO2 concentration, CS/MC/PVA/TiO2 (1 %) had the best biological properties.
- MeSH
- celulosa farmakologie MeSH
- chitosan * farmakologie chemie MeSH
- hydrogely farmakologie chemie MeSH
- lidé MeSH
- nanočástice * chemie MeSH
- polyvinylalkohol chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Titanium dioxide (TiO2) has been vastly used commercially, especially as white pigment in paints, colorants, plastics, coatings, cosmetics. Certain industrial uses TiO2 in diameter <100 nm. There are three common exposure routes for TiO2: (i) inhalation exposure, (ii) exposure via gastrointestinal tract, (iii) dermal exposure. Inhalation and gastrointestinal exposure appear to be the most probable ways of exposure, although nanoparticle (NP) penetration is limited. However, the penetration rate may increase substantially when the tissue is impaired. When TiO2 NPs migrate into the circulatory system, they can be distributed into all tissues including brain. In brain, TiO2 lead to oxidative stress mediated by the microglia phagocytic cells which respond to TiO2 NPs by the production and release of superoxide radicals that convert to multiple reactive oxygen species (ROS). The ROS production may also cause the damage of blood-brain barrier which then becomes more permeable for NPs. Moreover, several studies have showed neuron degradation and the impairment of spatial recognition memory and learning abilities in laboratory rodent exposed to TiO2 NPs.
- MeSH
- biologický transport MeSH
- hlodavci MeSH
- kovové nanočástice * toxicita MeSH
- mozek účinky léků metabolismus MeSH
- nanočástice toxicita MeSH
- neurotoxické syndromy * metabolismus patologie veterinární MeSH
- reaktivní formy kyslíku metabolismus MeSH
- titan farmakokinetika toxicita MeSH
- tkáňová distribuce MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
