[Determination of 24 elements migration in Yixing clay pottery by inductively coupled plasma mass spectrometry].

OBJECTIVE: To establish an analytical method for determining the migration of 24 elements in Yixing clay pottery in 4% acetic acid simulated solution by inductively coupled plasma mass spectrometry. METHODS: Four types of Yixing clay pottery, including Yixing clay teapot, Yixing clay kettle, Yixing clay pot, and Yixing clay electric stew pot, were immersed in 4% acetic acid as a food simulant for testing. The migration amount of 24 elements in the migration solution was determined using inductively coupled plasma mass spectrometry. RESULTS: Lithium, magnesium, aluminum, iron, and barium elements with a mass concentration of 1000 µg/L; Lead, cadmium, total arsenic, chromium, nickel, copper, vanadium, manganese, antimony, tin, zinc, cobalt, molybdenum, silver, beryllium, thallium, titanium, and strontium elements within 100 µg/L there was a linear relationship within, the r value was between 0.998 739 and 0.999 989. Total mercury at 5.0 µg/L, there was a linear relationship within, the r value of 0.995 056. The detection limit of the elements measured by this method was between 0.5 and 45.0 µg/L, the recovery rate was 80.6%-108.9%, and the relative standard deviation was 1.0%-4.8%(n=6). A total of 32 samples of four types of Yixing clay pottery sold on the market, including teapots, boiling kettles, casseroles, and electric stewing pots, were tested. It was found that the migration of 16 elements, including beryllium, titanium, chromium, nickel, cobalt, zinc, silver, cadmium, antimony, total mercury, thallium, tin, copper, total arsenic, molybdenum, and lead, were lower than the quantitative limit. The element with the highest migration volume teapot was aluminum, magnesium, and barium; The kettle was aluminum and magnesium; Casserole was aluminum, magnesium, and lithium; The electric stew pot was aluminum. CONCLUSION: This method is easy to operate and has high accuracy, providing an effective and feasible detection method for the determination and evaluation of element migration in Yixing clay pottery.

Foraging animal origin food samples as passive indicators of dioxin-like POPs contamination in industry sites: Method development, characterisation and risk assessment.

Titanium dioxide (TiO2) is an important industrial chemical, and studies suggest its major production route - the chloride process could lead to the generation of unintentional dl-POPs. However, no relevant studies assessed the occurrence of dl-POPs associated with TiO2 production in the industrial zones, which is mostly due to the ultra-trace level distribution of these compounds in environmental compartments. The present study explored the novel possibility of utilising foraging animal-origin foods as sensitive indicators for addressing this challenge and generated a globally beneficial dataset by assessing the background levels of dl-POPs in the vicinity of a TiO2 production house in Southern India. Systematic sampling of foraging cow's milk and free-ranging hen's eggs was carried out from the study site, and the dl-POPs assessments were conducted utilising an in-house developed cost-effective GC-MS/MS-based analytical methodology. The median dl-POPs levels in milk and egg samples were about 3 times higher than the control samples collected from farm-fed animals and retail markets. The contaminant loads in the foraging animal-origin food samples were further traced to their presence in environmental compartments of soil and sediment and admissible degree of correlations were observed in congener fingerprints. Elevated health risks were inferred for the population in the industrial zones with weekly intakes weighing about 0.15-17 times the European Food Safety Authority-assigned levels. The consumption of foraging cow's milk was observed to have a higher contribution towards the hazard indices and cancer risk estimates and were significantly higher (p < 0.05) for children. The study also presents a critical validation of the GC-MS/MS-based method for the purpose of regulatory monitoring of dl-POPs, which could be of practical significance in economies in transition.

Co-application of titanium nanoparticles and melatonin effectively lowered chromium toxicity in lemon balm (Melissa officinalis L.) through modifying biochemical characteristics.

Chromium (Cr) toxicity can negatively affect plant growth and development, impacting agricultural productivity and posing risks to human health. Metallic nanoparticles (MNPs) such as titanium dioxide (TiO2) and natural growth regulators such as melatonin (MT) become a promising technology to manage heavy metal-contaminated soils and promote safe food production. The present work was conducted to find the effect of foliar application of TiO2 NPs (15 mg L-1) and MT (100 µM) on growth, biochemical attributes, and Cr accumulation in plant tissues of Melissa officinalis L. under Cr toxicity (50 and 100 mg Cr kg-1 soil). The results showed that Cr toxicity led to decreased plant performance, where 100 mg Cr kg-1 soil led to notable decreases in shoot weight (28%), root weight (27%), essential oil (EO) yield (34%), chlorophyll (Chl) a + b (33%), while increased malondialdehyde (MDA, 30%), superoxide dismutase (SOD) activity (51%), and catalase (CAT) activity (122%). The use of TiO2 NPs and MT, particularly their co-application, remarkably reduced Cr toxicity by enhancing plant weight, Chl content, and lowered MDA and antioxidant activity. Total phenolic content (TPC), total flavonoid content (TFC), EO percentage, and rosmarinic acid in plants treated with Cr at 50 mg Cr kg-1 soil and co-application of TiO2 NPs and MT were relatively higher than in other treatments. Under 100 mg Cr kg-1 soil, the synergic effect of TiO2 NPs and MT-enhanced rosmarinic acid content (22%) but lowered Cr accumulation in roots (51%) and shoots (72%). Heat map analysis showed that CAT, SOD, MDA, and EO yield had the maximum variability under Cr, TiO2 NPs, and MT. Exogenous TiO2 NPs and MT can be recommended to modulate Cr toxicity in lemon balm under soil Cr toxicity.

Trace metals and nutrient analysis of marine fish species from the Gwadar coast.

Trace metals are naturally occurring metals found in very small concentrations in the environment. In the context of fish flesh, metals such as copper, calcium, potassium, sodium, zinc, iron, and manganese are absorbed by fish and play vital roles in various physiological functions. However, if these metals exceed the recommended limits set by WHO/FAO, they are termed 'toxic metals' due to their harmful impacts on both the fish and its consumers. Therefore, the present study aims to analyze the levels of protein, lipids, and certain metals-Aluminum (Al), Sodium (Na), Zinc (Zn), Titanium (Ti), Iron (Fe), Copper (Cu), Potassium (K), and Calcium (Ca) in three commercially important marine fishes i.e. Rastrelliger kanagurta, Sardinella abella, and Otolithes ruber. The study also aims to assess their potential impact on human health. The macro-Kjeldhal method and Soxhlet apparatus were used to estimate protein and lipid contents, while atomic absorption spectroscopy (AAS) was used to estimate trace metals found in fishes. The study found that these fish species are valuable sources of protein, lipids, and certain essential minerals. The protein content (CP) in these three species ranged from 63.35 to 86.57%, while lipid content was from 21.05 to 23.86%. The overall results of the trace metal concentrations analyzed in the present study revealed that Aluminum (Al), Sodium (Na), Zinc (Zn), Titanium (Ti), Copper (Cu), Potassium (K), and Calcium (Ca) were found in low concentration or traces and also within suitable ranges as set by WHO/FAO. However, Iron (Fe) was absent in all three species. Moreover, both copper and potassium were found in all three species, while Zinc was present in Rastrelliger kanagurta and Sardinella abella, calcium in Sardinella abella, and sodium in Otolithes ruber only. Titanium was recorded for the first time in S. abella. However, the total health risk assessment associated with these fish food consumption was measured by THQ and TTHQ and found to be less than 1, which shows no potential risk related to trace metals found in these fishes on human health upon their consumption. In conclusion, these commercially important marine fish species were found valuable sources of protein, lipids, and essential trace minerals that are necessary for human health. Thus, the current study provides useful information for the local population to make informed decisions about their daily diets and highlights the importance of sustainable fishing practices to maintain these valuable marine resources by periodical monitoring of their ecosystem.

Assessment of TiO2 (nano)particles migration from food packaging materials to food simulants by single particle ICP-MS/MS using a high efficiency sample introduction system.

TiO2 is the most widely used white pigment in plastics and food packaging industry, thus the question of its migration towards food and hence the impact on consumers is raised. Since recent research indicate its potential toxicity, it is necessary to study TiO2 contamination as a consequence of food storage. For this purpose, plastic containers from commercially-available dairy products and custom-made TiO2-spiked polypropylene materials were put in contact with 50% (v/v) ethanol and 3% (w/v) acetic acid, which were used here as food simulants. The migration assays were carried out under standard contact conditions of packaging use (as recommended by Commission Regulation (EU) N° 10/2011 for food contact migration testing), and under conditions of extreme mechanical degradation of the packaging. The TiO2 (nano)particles released in the food simulants were analysed by single particle inductively coupled plasma-tandem mass spectrometry in mass-shift mode and using a high efficiency sample introduction system (APEX™ Ω) to avoid matrix effects from food simulants. For the dairy product containers and for the spiked polypropylene, results showed release of TiO2 particles of rather large sizes (average size: 164 and 175 nm, respectively) under mechanical degradation conditions, i.e. when the polymeric structure is damaged. The highest amounts of TiO2 were observed in 50% ethanol after 10 days of storage at 50 °C (0.62 ng cm-2) for the dairy product containers and after 1 day of storage at 50 °C (0.68 ng cm-2) for the spiked polypropylene. However, the level of Ti released in particle form was very small compared to the total Ti content in the packaging and far below the acceptable migration limits set by European legislation. Release under standard contact conditions of use of the container was not measurable, thus the migration of TiO2 particles from this packaging to dairy products among storage is expected to be negligible.

Designed Directional Growth of Ti-Metal-Organic Frameworks for Decoding Alzheimer's Disease-Specific Exosome Metabolites.

Exosomes, a growing focus for liquid biopsies, contain diverse molecular cargos. In particular, exosome metabolites with valuable information have exhibited great potential for improving the efficiency of liquid biopsies for addressing complex medical conditions. In this work, we design the directional growth of Ti-metal-organic frameworks on polar-functionalized magnetic particles. This design facilitates the rapid synergistic capture of exosomes with the assistance of an external magnetic field and additionally synergistically enhances the ionization of their metabolites during mass spectrometry detection. Benefiting from this dual synergistic effect, we identified three high-performance exosome metabolites through the differential comparison of a large number of serum samples from individuals with Alzheimer's disease (AD) and normal cognition. Notably, the accuracy of AD identification ranges from 93.18 to 100% using a single exosome metabolite and reaches a flawless 100% with three metabolites. These findings emphasize the transformative potential of this work to enhance the precision and reliability of AD diagnosis, ushering in a new era of improved diagnostic accuracy.

A Wearable Electrochemical Biosensor Utilizing Functionalized Ti3C2Tx MXene for the Real-Time Monitoring of Uric Acid Metabolite.

Wearable, noninvasive sensors enable the continuous monitoring of metabolites in sweat and provide clinical information related to an individual's health and disease states. Uric acid (UA) is a key indicator highly associated with gout, hyperuricaemia, hypertension, kidney disease, and Lesch-Nyhan syndrome. However, the detection of UA levels typically relies on invasive blood tests. Therefore, developing a wearable device for noninvasive monitoring of UA concentrations in sweat could facilitate real-time personalized disease prevention. Here, we introduce 1,3,6,8-pyrene tetrasulfonic acid sodium salt (PyTS) as a bifunctional molecule functionalized with Ti3C2Tx via π-π conjugation to design nonenzymatic wearable sensors for sensitive and selective detection of UA concentration in human sweat. PyTS@Ti3C2Tx provides many oxidation-reduction active groups to enhance the electrocatalytic ability of the UA oxidation reaction. The PyTS@Ti3C2Tx-based electrochemical sensor demonstrates highly sensitive detection of UA in the concentration range of 5 µM-100 µM, exhibiting a lower detection limit of 0.48 µM compared to the uricase-based sensor (0.84 µM). In volunteers, the PyTS@Ti3C2Tx-based wearable sensor is integrated with flexible microfluidic sweat sampling and wireless electronics to enable real-time monitoring of UA levels during aerobic exercise. Simultaneously, it allows for comparison of blood UA levels via a commercial UA analyzer. Herein, this study provides a promising electrocatalyst strategy for nonenzymatic electrochemical UA sensor, enabling noninvasive real-time monitoring of UA levels in human sweat and personalized disease prevention.

Titanium-doped PET nanoplastics, from opaque milk bottle degradation, as a model of environmental true-to-life nanoplastics. Hazardous effects on Drosophila.

Micro and nanoplastics (MNPLs) are emergent environmental pollutants, resulting from the degradation of plastic waste, requiring urgent information on their potential risks to human health. To determine such risks, reliable true-to-life materials are essential. In this work, we have used titanium-doped PET NPLs [PET(Ti)NPLs], obtained by grinding opaque milk polyethylene terephthalate (PET) bottles, as a true-to-life MNPLs model. These opaque PET bottles, with an average size of 112 nm, contain about 3% Ti in the form of titanium dioxide rod nanoparticles. TEM investigation confirmed the mixed Ti/PET nature of the obtained true-to-life NPLs, and the rod shape of the embedded TiO2NPs. In the in vivo Drosophila model neither PET(Ti)NPLs nor TiO2NPs reduced the survival rates, although their internalization was confirmed in different compartments of the larval body by using confocal and transmission electron microscopies. The presence of Ti in the PET(Ti)NPLs permitted to quantify its presence both in larvae (2.1 ± 2.2 µg/g of Ti) and in the resulting adults (3.4 ± 3.2 µg/g of Ti) after treatment with 500 µg/g food of PET(Ti)NPL, suggesting its potential use to track their fate in more complex organisms such as mammals. PET(Ti)NPLs, as well as TiO2NPs, altered the expression of genes driving different response pathways, inducing significant oxidative stress levels (up to 10 folds), and genotoxicity. This last result on the genotoxic effects is remarkable in the frame of the hot topic discussion on the risk that titanium compounds, used as food additives, may pose to humans.

Efficient multi-stage electrochemical flow-through system for refractory organic pollutant treatment: Kinetics, mass transfer, and thermodynamic analysis.

Improving the kinetics rate and mass transfer is essential for expanding the potential of electrochemical technologies in wastewater treatment. The electrochemical flow-through configuration promises a high oxidation efficiency and low energy consumption. We aimed to provide a thorough understanding of the enhanced kinetics, mass transfer, and thermodynamic parameters during the degradation of amoxicillin (AMX) in a multi-stage flow-through (MSFT) system using porous Ti-ENTA/SnO2-Sb anodes. All operating conditions strongly influenced the kinetics of AMX degradation and followed pseudo-first-order rate kinetic model (R2 > 0.85), with the highest kobs of 0.228 min-1 at high temperature (318 K). In comparison to the flow-by mode, the AMX removal rate in the three-stage flow-through mode was greatly enhanced by 70%, exhibiting the superior capacity of a porous anode. This system exhibited outstanding performance regarding the high kinetics rate and mass transfer rate (km), which increased by factors of 3.46 and 10.74, respectively, obtained in the flow-by mode. It also revealed that •OH generation was 5.64 times higher, and the EE/O was 19.89-fold lower than those in flow-by mode. Temperature plays a vital role in the reaction process, and thermodynamic features found the positive enthalpy (ΔHo) of +27.06 kJ mol-1, signifying the process was endothermic. A Hatta number (Ha) of >0.02 at all temperatures proved this finding, confirming an undeniable role in mass transfer. Finally, these findings reveal the system's performance and offer the possibility of establishing a multi-stage flow-through for wastewater treatment.

Titanium Particles Modulate Lymphocyte and Macrophage Polarization in Peri-Implant Gingival Tissues.

Titanium dental implants are one of the modalities to replace missing teeth. The release of titanium particles from the implant's surface may modulate the immune cells, resulting in implant failure. However, little is known about the immune microenvironment that plays a role in peri-implant inflammation as a consequence of titanium particles. In this study, the peri-implant gingival tissues were collected from patients with failed implants, successful implants and no implants, and then a whole transcriptome analysis was performed. The gene set enrichment analysis confirmed that macrophage M1/M2 polarization and lymphocyte proliferation were differentially expressed between the study groups. The functional clustering and pathway analysis of the differentially expressed genes between the failed implants and successful implants versus no implants revealed that the immune response pathways were the most common in both comparisons, implying the critical role of infiltrating immune cells in the peri-implant tissues. The H&E and IHC staining confirmed the presence of titanium particles and immune cells in the tissue samples, with an increase in the infiltration of lymphocytes and macrophages in the failed implant samples. The in vitro validation showed a significant increase in the level of IL-1ß, IL-8 and IL-18 expression by macrophages. Our findings showed evidence that titanium particles modulate lymphocyte and macrophage polarization in peri-implant gingival tissues, which can help in the understanding of the imbalance in osteoblast-osteoclast activity and failure of dental implant osseointegration.

Raman mapping for determination of TiO2 in different solid food samples by multivariate curve resolution with alternating least squares.

Titanium dioxide is a food additive commonly used as a white food coloring (E171). Its wide use by the food industry associated with the nanometric size distribution of the particles of this pigment has shown high genotoxicity associated with recurrent exposure by ingestion. Therefore, the use of E171 in food products has already been banned by some industries and in the European Union. Such banishment should soon be extended to other countries around the world, making it important to establish techniques for the efficient determination of TiO2 in different food products. The association between hyperspectral images and chemometric tools can be useful in this sense, aiming to enable the use of a single method for sample preparation and analysis of different types of food. Thus, the present work aims to evaluate the use of Raman mapping associated with the resolution of multivariate curves with alternating least squares (MCR-ALS) for the determination of titanium dioxide in solid food samples with different compositions, without the need to introduce specific sample preparation. The proposed method allowed for the first-time quantification of TiO2 in different food matrices without specific sample preparation, with a simple, rapid, accurate (93% of recovery), low detection limits (0.0111% m/m) and quantification (0.0370% m/m) and adequate linearity (r = 0.9990) and precise (standard deviation around 0.020-0.030% w/w) methodology. Such results highlight the potential use of Raman mapping associated with the MCR-ALS for quantification of the nano-TiO2 in commercial samples.

Dynamics of vanadium and response of inherent bacterial communities in vanadium-titanium magnetite tailings to beneficiation agents, temperature, and illumination.

Vanadium-titanium (V-Ti) magnetite tailings contain toxic metals that could potentially pollute the surrounding environment. However, the impact of beneficiation agents, an integral part of mining activities, on the dynamics of V and the microbial community composition in tailings remains unclear. To fill this knowledge gap, we compared the physicochemical properties and microbial community structure of V-Ti magnetite tailings under different environmental conditions, including illumination, temperature, and residual beneficiation agents (salicylhydroxamic acid, sodium isobutyl xanthate, and benzyl arsonic acid) during a 28-day reaction. The results revealed that beneficiation agents exacerbated the acidification of the tailings and the release of V, among which benzyl arsonic acid had the greatest impact. The concentration of soluble V in the leachate of tailings with benzyl arsonic acid was 6.4 times higher than that with deionized water. Moreover, illumination, high temperatures, and beneficiation agents contributed to the reduction of V in V-containing tailings. High-throughput sequencing revealed that Thiobacillus and Limnohabitans adapted to the tailings environment. Proteobacteria was the most diverse phylum, and the relative abundance was 85.0%-99.1%. Desulfovibrio, Thiobacillus, and Limnohabitans survived in the V-Ti magnetite tailings with residual beneficiation agents. These microorganisms could contribute to the development of bioremediation technologies. The main factors affecting the diversity and composition of bacteria in the tailings were Fe, Mn, V, SO42-, total nitrogen, and pH of the tailings. Illumination inhibited microbial community abundance, while the high temperature (39.5 °C) stimulated microbial community abundance. Overall, this study strengthens the understanding of the geochemical cycling of V in tailings influenced by residual beneficiation agents and the application of inherent microbial techniques in the remediation of tailing-affected environments.

Characterisation of engineered titanium dioxide nanoparticles in selected food.

Titanium dioxide (TiO2), an E171 manufacturer-made food additive, is extensively utilised as a colourant in drug and a food products. Some studies showed that most of confectionary and food items contain inexplicable particles. The aim of this article is to determine the size and structure of TiO2 nanoparticles in different food products. Ten food samples, including coffee cream, white chocolate concentrate, frosting, gum, yoghurt candy, hard candies and chewy candies, were investigated for this purpose. The crystalline structure and particle size of TiO2 were determined by Powder X-ray Diffraction (PXRD) and Transmission Electron Microscopy (TEM). TEM images revealed that a few of the extracted nanoparticles had a rod-like shape, but most were spherical. Also, the size of the TiO2 particle had a wide distribution between 12 and 450 nm. Thus, to avoid human health risk, crucial factors such as size, and shape should be considered and regulated by food authorities.

Tracking soluble and nanoparticulated titanium released in vivo from metal dental implant debris using (single-particle)-ICP-MS.

BACKGROUND: This work studies the presence of the Ti, Al and V metal ions and Ti nanoparticles released from the debris produced by the implantoplasty, a surgical procedure used in the clinic, in rat organs. METHODS: The sample preparation for total Ti determination was carefully optimized using microsampling inserts to minimize the dilution during the acid attack of the lyophilized tissues by a microwave-assisted acid digestion method. An enzymatic digestion method was optimized and applied to the different tissue samples in order to extract the titanium nanoparticles for the single-particle ICP-MS analysis. RESULTS: A statistically significant increase was found for Ti concentrations from control to experimental groups for several of the studied tissues, being and particularly significant in the case of brain and spleen. Al and V concentrations were detected in all tissues but they were not different when comparing control and experimental animals, except for V in brain. The possible presence of Ti-containing nanoparticles mobilized from the implantoplasty debris was tested using enzymatic digestions and SP-ICP-MS. The presence of Ti-containing nanoparticles was observed in all the analyzed tissues, however, differences on the Ti mass per particle were found between the blanks and the digested tissue and between control and experimental animals in some organs. CONCLUSION: The developed methodologies, both for ionic and nanoparticulated metal contents in rat organs, have shown the possible increase in the levels of Ti both as ions and nanoparticles in rats subjected to implantoplasty.

Anthracene removal potential of green synthesized titanium dioxide nanoparticles (TiO2-NPs) and Alcaligenes faecalis HP8 from contaminated soil.

Anthracene biodegradation potential has been studied in liquid culture and soil microcosm environment by employing green synthesized TiO2 nanoparticles (NPs) and Alcaligenes faecalis HP8. The bacterium was isolated from crude oil contaminated soil, while TiO2 nanoparticles were synthesized using Paenibacillus sp. HD1PAH and Cyperus brevifolius which have PAHs remediation abilities. The dual application of TiO2 nanoparticles and Alcaligenes faecalis HP8 decreases anthracene concentration up to 21.3% in liquid at the end of 7 days and 37.9% in the soil treatments after completion of 30 days. Besides, the GC-MS analysis revealed production of five metabolites including 1,2-anthracenedihydrodiol; 6,7-benzocoumarin; 3-hydroxy-2-naphthoic acid; salicylic acid and 9,10-anthraquinone at different time interval of the treatments. Anthracene degradation pathway confirms the breakdown of three ring anthracene to one ring salicylic acid. Additionally, soil dehydrogenase, urease, alkaline phosphatase, catalase and amylase activities increased up to 4.09 folds, 8.6 folds, 4.4 folds, 3.6 folds and 2.1 folds respectively after the combined treatments of TiO2 nanoparticles and Alcaligenes faecalis HP8. The bacterial biomass and residual anthracene concentration were found to be negatively correlated. Finally, the study brings into light a novel anthracene biodegradation pathway and provides a new dimension in nano assisted bacterial remediation.

Novel three-dimensional Ti3C2-MXene embedded zirconium alginate aerogel adsorbent for efficient phosphate removal in water.

Excessive phosphorus in water causes environmental security problems like eutrophication. Advanced two-dimensional material MXene has attracted raising attention in aquatic adsorption, while lack of selectivity and difficult recovery limit its application in phosphate removal. In this study, Ti3C2-MXene embedded zirconium-crosslinked SA (MX-ZrSA) beads were synthesized and their phosphate adsorption performance under different conditions was assessed. Investigations using SEM/EDS, XRD, BET, TGA and contact angle meter reveal that the addition of Ti3C2-MXene enhanced the thermal stability, mechanical strength, hydrophilicity, and formed loose network-like mesoporous inner structure with large surface area. The theoretical maximum adsorption capacity was 492.55 mg P/g and was well fitted by Freundlich and optimized Langmuir models. The Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis showed that chemisorption was involved, and the formation of Zr-O-P and Ti-O-P complexes accounted for high selectivity and affinity to phosphate. The adsorption experiments in real waters and lab-scale continuous flow Anaerobic-Anoxic-Oxic reactor further indicated the application potential of MX-ZrSA beads. Our study will provide insight into MXene and SA aerogel synergistic adsorption of aquatic contaminants and help with the removal and recovery of finite phosphorus resource.

Effect of Glucose Contents on Electrochemical Corrosion Behavior of Ti/ZrO2 Brazing Joint in SBF.

The effect of glucose content on the electrochemical corrosion behavior of the Ti/ZrO2 brazing joint in simulated body fluid (SBF) was researched by the means of SEM morphologies, electrochemical and XPS analyses. Herein, pitting is observed to be a dominating corrosion model under the investigated glucose content. The pitting corrosion of the joint in 200 mg/dL SBF is minimal. In addition, the joint in 200 mg/dL SBF manifests the best corrosion resistance by electrochemical analyses, which indicates that glucose content has a bidirectional effect on corrosion of the Ti/ZrO2 brazing joint. Additionally, the corrosion current value and impedance of titanium and brazing joint are close, which indicates that their corrosion resistance is similar. Finally, the OH-, Cl-, Sn2+/Sn4+ and -COOH on the joint surface are found by XPS analysis, and the mechanism of Ti/ZrO2 brazing joint corrosion is elucidated. The study provides a novel understanding of the corrosion behavior and relevant corrosion mechanism of the Ti/ZrO2 brazing joint in body fluids with different glucose content.

Cell-Molecular Interactions of Nano- and Microparticles in Dental Implantology.

The role of metallic nano- and microparticles in the development of inflammation has not yet been investigated. Soft tissue biopsy specimens of the bone bed taken during surgical revisions, as well as supernatants obtained from the surface of the orthopedic structures and dental implants (control), were examined. Investigations were performed using X-ray microtomography, X-ray fluorescence analysis, and scanning electron microscopy. Histological studies of the bone bed tissues were performed. Nanoscale and microscale metallic particles were identified as participants in the inflammatory process in tissues. Supernatants containing nanoscale particles were obtained from the surfaces of 20 units of new dental implants. Early and late apoptosis and necrosis of immunocompetent cells after co-culture and induction by lipopolysaccharide and human venous blood serum were studied in an experiment with staging on the THP-1 (human monocytic) cell line using visualizing cytometry. As a result, it was found that nano- and microparticles emitted from the surface of the oxide layer of medical devices impregnated soft tissue biopsy specimens. By using different methods to analyze the cell-molecule interactions of nano- and microparticles both from a clinical perspective and an experimental research perspective, the possibility of forming a chronic immunopathological endogenous inflammatory process with an autoimmune component in the tissues was revealed.

Exfoliated oral mucosa cells as bioindicators of short- and long-term systemic titanium contamination.

BACKGROUND: Humans are exposed to exogenous sources of titanium-containing particles that can enter the body mainly by inhalation, ingestion, or dermal absorption. Given the widespread use of biomaterials in medicine, the surface of a titanium (Ti) biomedical device is a potential endogenous source of Ti ions and/or Ti-containing particles, such as TiO2 micro-(MPs) and nano-particles (NPs), resulting from biotribocorrosion processes. Ti ions or Ti-containing particles may deposit in epithelial cells of the oral mucosa, and the latter may therefore serve as bioindicators of short and long-term systemic Ti contamination. The aim of the present study was to histologically and quantitatively evaluate the presence of Ti traces in cells exfoliated from the oral mucosa as possible bioindicators of systemic contamination with this metal at short and long-term experimental time points METHODS: Thirty Wistar rats were intraperitoneally injected with a suspension of titanium dioxide (TiO2) (0.16 g/100 g body weight of TiO2 in 5 ml of NaCl 0.9%) using 5 nm NPs (Group: TiO2-NP5; n = 10), 45 µm MPs (Group: TiO2-MP45; n = 10), or vehicle alone (Control group; n = 10). At one and six months post-injection, right-cheek mucosa cells were obtained by exfoliative cytology using a cytobrush; they were spray fixed and stained using Safranin or the Papanicolaou technique. The smears were cytologically evaluated (light microscopy) to determine the presence of particulate material, which was also analyzed microchemically (SEM-EDS). Left-cheek mucosa cells were similarly obtained and re-suspended in 5 ml of PBS (pH: 7.2-7.4); the samples corresponding to each group were pooled together and analyzed spectrometrically (ICP-MS) to determine Ti concentration in each of the studied groups. Blood samples were obtained for histological determination of the presence of particulate material on Safranin-stained blood smears and determination of plasma concentration of Ti by ICP-MS RESULTS: Different size and shape metal-like particles were observed inside and outside epithelial cells in TiO2-NP5 and TiO2-MP45 cytological smears at both one and six months post-injection. EDS analysis showed the presence of Ti in the particles. ICP-MS revealed higher Ti concentrations in both TiO2 injected groups compared to the control group. In addition, Ti concentration did not vary with time or particle size. Monocytes containing particles were observed in blood smears of TiO2-exposed animals one- and six-months post-injection. Plasma levels of Ti were significantly higher in TiO2-NP5- and TiO2-MP45- exposed animals than in controls (p < 0.05), and Ti concentration was significantly higher at one month than at six months in both TiO2-exposed groups (p < 0.05). CONCLUSIONS: Cells exfoliated from the oral mucosa could be used as bioindicators of short- and long-term systemic contamination with Ti. Exfoliative cytology could be used as a simple, non-invasive, and inexpensive diagnostic method for monitoring biotribocorrosion of Ti implants and patient clinical follow-up.

Ion release and local effects of titanium metal particles from dental implants: An experimental study in rats.

BACKGROUND: The objective of this study was to evaluate the accumulation of ions in blood and organs caused by titanium (Ti) metal particles in a mandibular defect in rats, together with a description of the local reaction of oral tissues to this Ti alloy debris. METHODS: Twenty Sprague-Dawley rats were randomly distributed into three groups: an experimental group with a mandibular bone defect filled with metallic debris obtained by implantoplasty; a positive control group; and a negative control group. Thirty days after surgery, the rats were euthanized and perilesional tissue surrounding the mandibular defect was removed, together with the lungs, spleen, liver, and brain. Two blood samples were collected: immediately before surgery and before euthanasia. The perilesional tissue was histologically analyzed using hematoxylin-eosin staining, and Ti, aluminum, and vanadium ion concentrations in blood and organs were measured by TQ-ICP-MS. Descriptive and bivariate analyses of the data were performed. RESULTS: All rats with implanted metal debris showed metal particles and a bone fracture callus on the osseous defect. The metal particles were surrounded by a foreign body reaction characterized by the presence of histiocytes and multinucleated giant cells (MNGCs). The experimental group had a significant higher concentration of Ti ions in all studied organs except lung tissue (p < 0.05). In addition, there were more V ions in the brain in the experimental group (p = 0.008). CONCLUSIONS: Although further studies are required to confirm the clinical relevance of these results, Ti metal particles in the jaw might increase the concentration of metal ions in vital organs and induce a foreign body reaction.