reduced TiO2
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INTRODUCTION: A critical step preceding the potential biomedical application of nanoparticles is the evaluation of their immunomodulatory effects. Such nanoparticles are expected to enter the bloodstream where they can be recognized and processed by circulating monocytes. Despite the required biocompatibility, this interaction can affect intracellular homeostasis and modulate physiological functions, particularly inflammation. This study focuses on titanium dioxide (TiO2) as an example of relatively low cytotoxic nanoparticles with potential biomedical use and aims to evaluate their possible modulatory effects on the inflammasome-based response in human primary monocytes. METHODS: Monocyte viability, phenotypic changes, and cytokine production were determined after exposure to TiO2 (diameter, 25 nm; P25) alone. In the case of the modulatory effects, we focused on NLRP3 activation. The production of IL-1β and IL-10 was evaluated after (a) simultaneous activation of monocytes with bacterial stimuli muramyl dipeptide (MDP), or lipopolysaccharide (LPS), and TiO2 (co-exposure model), (b) prior activation with TiO2 alone and subsequent exposure to bacterial stimuli MDP or LPS. The differentiation of TiO2-treated monocytes into macrophages and their polarization were also assessed. RESULTS: The selected TiO2 concentration range (30-120 μg/mL) did not induce any significant cytotoxic effects. The highest dose of TiO2 promoted monocyte survival and differentiation into macrophages, with the M2 subset being the most prevalent. Nanoparticles alone did not induce substantial production of inflammatory cytokines IL-1β, IL-6, or TNF-α. The immunomodulatory effect on NLRP3 depended on the type of costimulant used. While co-exposure of monocytes to MDP and TiO2 boosted NLRP3 activity, co-exposure to LPS and TiO2 inhibited NLRP3 by enhancing IL-10 release. The inhibitory effect of TiO2 on NLRP3 based on the promotion of IL-10 was confirmed in a post-exposure model for both costimulants. CONCLUSION: This study confirmed a non-negligible modulatory effect on primary monocytes in their inflammasome-based response and differentiation ability.
- MeSH
- acetylmuramyl-alanyl-isoglutamin farmakologie MeSH
- buněčná diferenciace účinky léků MeSH
- cytokiny metabolismus MeSH
- inflamasomy účinky léků MeSH
- interleukin-10 metabolismus MeSH
- interleukin-1beta metabolismus MeSH
- kovové nanočástice chemie toxicita MeSH
- kultivované buňky MeSH
- lidé MeSH
- lipopolysacharidy * farmakologie MeSH
- makrofágy účinky léků MeSH
- monocyty * účinky léků MeSH
- nanočástice chemie toxicita MeSH
- protein NLRP3 * metabolismus MeSH
- titan * chemie farmakologie toxicita MeSH
- viabilita buněk * účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Malaria is a serious global health challenge, and it has infected millions of people worldwide. There is an urgent need for new antimalarial drugs and drug targets for both prophylaxis and chemotherapy. In the present study, we biosynthesized TiO2 nanoparticles (NPs) using the Momordica charantia leaf aqueous extract as a reducing and stabilizing agent. TiO2 NPs were characterized by UV, XRD, FTIR, HRTEM, EDX, DLS and Zeta-potential. The maximum activity of mosquitocidal was observed in the synthesized TiO2 NPs against Anopheles stephensi Liston (Diptera: Culicidae) larvae and pupae, LC50 were 2.50 mg/l (I instar), 2.86 mg/l (II), 3.29 mg/l (III), 3.43 mg/l (IV), and 5.04 mg/l (pupa). The antimalarial activity of M. charantia leaf aqueous extract and TiO2 NPs were evaluated against CQ-resistant (CQ-r) and CQ sensitive (CQ-s) strains of Plasmodium falciparum. IC50 of M. charantia leaf aqueous extract were 83.64 μg/ml (CQ-s) and 88.14 μg/ml (CQ-r). Synthesized TiO2 NPs achieved IC50 of 53.42 μg/ml (CQ-s) and 59.71 μg/ml (CQ-r). The TiO2 NPs did not exhibit any noticeable toxicity on Poecilia reticulata after 24 h of exposure. Overall, our results suggest that the synthesized TiO2 NPs may be employed to develop newer and safer agents for malaria control.
BACKGROUND: Targeted alpha therapy (TAT) is an effective option for cancer treatment. To maximize its efficacy and minimize side effects, carriers must deliver radionuclides to target tissues. Most of the nuclides used in TAT decay via the alpha cascade, producing several radioactive daughter nuclei with sufficient energy to escape from the original carrier. Therefore, studying these daughter atoms is crucial in the search for new carriers. Nanoparticles have potential as carriers due to their structure, which can prevent the escape of daughter atoms and reduce radiation exposure to non-target tissues. This work focuses on determining the released activity of 221Fr and 213Bi resulting from the decay of 225Ac labelled TiO2 nanoparticles. RESULTS: Labelling of TiO2 nanoparticles has shown high sorption rates of 225Ac and its progeny, 221Fr and 213Bi, with over 92 % of activities sorbed on the nanoparticle surface for all measured radionuclides. However, in the quasi-dynamic in vitro system, the released activity of 221Fr and 213Bi is strongly dependent on the nanoparticles concentration, ranging from 15 % for a concentration of 1 mg/mL to approximately 50 % for a nanoparticle concentration of 10 μg/mL in saline solution. The released activities of 213Bi were lower, with a maximum value of around 20 % for concentrations of 0.05, 0.025, and 0.01 mg/mL. The leakage of 225Ac and its progeny was tested in various biological matrices. Minimal released activity was measured in saline at around 10 % after 48 h, while the maximum activity was measured in blood serum and plasma at 20 %. The amount of 225Ac released into the media was minimal (<3 %). The in vitro results were confirmed in a healthy mouse model. The difference in %ID/g was clearly visible immediately after dissection and again after 6 h when 213Bi reached equilibrium with 225Ac. CONCLUSION: The study verified the potential release of 225Ac progeny from the labelled TiO2 nanoparticles. Experiments were performed to determine the dependence of released activity on nanoparticle concentration and the biological environment. The results demonstrated the high stability of the prepared 225Ac@TiO2 NPs and the potential release of progeny over time. In vivo studies confirmed our hypothesis. The data obtained suggest that the daughter atoms can escape from the original carrier and follow their own biological pathways in the organism.
- MeSH
- aktinium * chemie MeSH
- izotopové značení MeSH
- myši MeSH
- nanočástice * chemie MeSH
- radionuklidy chemie MeSH
- titan * chemie MeSH
- tkáňová distribuce MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Titanium dioxide nanoparticles (TiO2 NPs) are used in a wide range of applications. Although inhalation of NPs is one of the most important toxicologically relevant routes, experimental studies on potential harmful effects of TiO2 NPs using a whole-body inhalation chamber model are rare. In this study, the profile of lymphocyte markers, functional immunoassays, and antioxidant defense markers were analyzed to evaluate the potential adverse effects of seven-week inhalation exposure to two different concentrations of TiO2 NPs (0.00167 and 0.1308 mg TiO2/m3) in mice. A dose-dependent effect of TiO2 NPs on innate immunity was evident in the form of stimulated phagocytic activity of monocytes in low-dose mice and suppressed secretory function of monocytes (IL-18) in high-dose animals. The effect of TiO2 NPs on adaptive immunity, manifested in the spleen by a decrease in the percentage of T-cells, a reduction in T-helper cells, and a dose-dependent decrease in lymphocyte cytokine production, may indicate immunosuppression in exposed mice. The dose-dependent increase in GSH concentration and GSH/GSSG ratio in whole blood demonstrated stimulated antioxidant defense against oxidative stress induced by TiO2 NP exposure.
- Publikační typ
- časopisecké články MeSH
An investigation was made of the adhesion, growth and differentiation of osteoblast-like MG-63 and Saos-2 cells on titanium (Ti) and niobium (Nb) supports and on TiNb alloy with surfaces oxidized at 165°C under hydrothermal conditions and at 600°C in a stream of air. The oxidation mode and the chemical composition of the samples tuned the morphology, topography and distribution of the charge on their surfaces, which enabled us to evaluate the importance of these material characteristics in the interaction of the cells with the sample surface. Numbers of adhered MG-63 and Saos-2 cells correlated with the number of positively-charged (related with the Nb2O5 phase) and negatively-charged sites (related with the TiO2 phase) on the alloy surface. Proliferation of these cells is correlated with the presence of positively-charged (i.e. basic) sites of the Nb2O5 alloy phase, while cell differentiation is correlated with negatively-charged (acidic) sites of the TiO2 alloy phase. The number of charged sites and adhered cells was substantially higher on the alloy sample oxidized at 600°C than on the hydrothermally treated sample at 165°C. The expression values of osteoblast differentiation markers (collagen type I and osteocalcin) were higher for cells grown on the Ti samples than for those grown on the TiNb samples. This was more particularly apparent in the samples treated at 165°C. No considerable immune activation of murine macrophage-like RAW 264.7 cells on the tested samples was found. The secretion of TNF-α by these cells into the cell culture media was much lower than for either cells grown in the presence of bacterial lipopolysaccharide, or untreated control samples. Thus, oxidized Ti and TiNb are both promising materials for bone implantation; TiNb for applications where bone cell proliferation is desirable, and Ti for induction of osteogenic cell differentiation.
- MeSH
- biologické markery metabolismus MeSH
- buněčná adheze účinky léků MeSH
- buněčná diferenciace účinky léků MeSH
- buněčné linie MeSH
- kolagen typu I metabolismus MeSH
- lidé MeSH
- lipopolysacharidy farmakologie MeSH
- makrofágy cytologie účinky léků metabolismus MeSH
- myši MeSH
- osteoblasty cytologie účinky léků metabolismus MeSH
- osteokalcin metabolismus MeSH
- oxidace-redukce MeSH
- povrchové vlastnosti MeSH
- proliferace buněk účinky léků MeSH
- slitiny chemie farmakologie MeSH
- statická elektřina MeSH
- tkáňové podpůrné struktury * MeSH
- TNF-alfa farmakologie MeSH
- vysoká teplota MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
This article presents a comparison of 2 very different options for removal of undesirable microorganisms and airborne pollutants from the indoor environment of hospitals, schools, homes, and other enclosed spaces using air purifiers and photocatalytic coatings based on nano titanium dioxide (TiO2 ). Both products were assessed by life cycle assessment (LCA) methodology from cradle-to-grave. The assessment also includes comparison of 2 different nano TiO2 production technologies, one by continuous hydrothermal synthesis and the other by a sulfate process. Results of the study showed a relatively large contribution of photocatalytic coatings to reducing the effects of selected indices in comparison with an air purifier, regardless of which nano TiO2 production method is used. Although the impacts of the sulfate process are significantly lower compared to those of hydrothermal synthesis when viewed in terms of production alone, taken in the context of the entire product life cycle, the net difference becomes less significant. The study has been elaborated within the Sustainable Hydrothermal Manufacturing of Nanomaterials (SHYMAN) project, which aims to develop competitive and sustainable continuous nanoparticle (NP) production technology based on supercritical hydrothermal synthesis. Integr Environ Assess Manag 2016;12:478-485. © 2016 SETAC.
The impact of four pre-treatment techniques on the surface morphology and chemistry, residual stress, mechanical properties, corrosion resistance in a physiological saline solution and cell colonization of commercially pure titanium is examined in detail. Mechanical polishing, electrochemical etching, chemical etching in Kroll's reagent, and ion sputter etching with argon ions were applied. Surface morphologies reflect the nature of surface layer removal. Significant roughening of the surface and a characteristic microtopology become apparent as a result of the sensitivity of chemical and ion sputter etching to the grain orientation. The hardness in the near surface region was controlled by the amount of residual stress. Etching of the stressed surface layer led to a reduction in residual stress and surface hardness. A compact passivation layer composed of TiO, TiO2 and Ti2O3 native oxides imparted high corrosion resistance to the surface after mechanical polishing, chemical and electrochemical etching. The ion sputter etched surface showed substantially reduced corrosion resistance, where the corrosion process was controlled by electron transfer. The specific topology affected the adhesion of the cell to the surface rather than the cell area coverage. The cell area coverage increased with the corrosion stability of the surface.
- MeSH
- buněčné linie MeSH
- elektrochemické techniky MeSH
- koroze MeSH
- lidé MeSH
- oxidy chemie MeSH
- povrchové vlastnosti MeSH
- testování materiálů MeSH
- titan chemie MeSH
- tvrdost MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články 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.
- 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
