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Cerium and cobalt loaded Co-Ce/TiO2 catalyst prepared by impregnation method was investigated for photothermal catalytic toluene oxidation. Based on catalyst characterizations (XPS, EPR and H2-TPR), redox cycle between Co and TiO2 (Co2+ + Ti4+ ↔ Co3+ + Ti3+) results in the formation of Co3+, Ti3+ and oxygen vacancies, which play important roles in toluene catalytic oxidation reaction. The introduction of Ce brings in the dual redox cycles (Co2+ + Ti4+ ↔ Co3+ + Ti3+, Co2+ + Ce4+ ↔ Co3+ + Ce3+), further promoting the elevation of reaction sites amount. Under full spectrum irradiation with light intensity of 580 mW/cm2, Co-Ce/TiO2 catalyst achieved 96% of toluene conversion and 73% of CO2 yield, obviously higher than Co/P25 and Co/TiO2. Co-Ce/TiO2 efficiently maintains 10-hour stability test under water vapor conditions and exhibits better photothermal catalytic performance than counterparts under different wavelengths illumination. Photothermal catalytic reaction displays improved activities compared with thermal catalysis, which is attributed to the promotional effect of light including photocatalysis and light activation of reactive oxygen species.

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The rapid expansion of industrial activities has resulted in severe environmental pollution manifested by organic dyes discharged from the food, textile, and leather industries, as well as hazardous gas emissions from various industrial processes. Titanium dioxide (TiO2)-nanostructured materials have emerged as promising candidates for effective photocatalytic dye degradation and gas sensing applications owing to their unique physicochemical properties. This study investigates the development of a photocatalyst and a liquefied petroleum gas (LPG) sensor using hydrothermally synthesized globosa-like TiO2 nanostructures (GTNs). The synthesized GTNs are then evaluated to photocatalytically degrade methylene blue dye, resulting in an outstanding photocatalytic activity of 91% degradation within 160 min under UV light irradiation. Furthermore, these nanostructures are utilized to sense liquefied petroleum gas, which attains a superior sensitivity of 7.3% with high response and recovery times and good reproducibility. This facile and cost-effective hydrothermal method of fabricating TiO2 nanostructures opens a new avenue in photocatalytic dye degradation and gas sensing applications.

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NANOTECHNOLOGY: is the art and science of dealing with nanoscale particles. This has transformed contemporary dental practices through myriad contributions to biomaterial science. Titanium dioxide nanoparticles procured from Bacillus subtilis, an eco-friendly and biogenic source, can significantly magnify the physiochemical attributes of dental materials. However, postoperative sensitivity is a major drawback of composite restorations. The incorporation of these nanoparticles into dental adhesives can greatly benefit clinical dentistry by resolving this issue. This trial aimed to evaluate the effectiveness of a novel titanium dioxide nanofortified adhesive on the postoperative sensitivity of composite restorations. METHODS: This triple-blind, parallel-group randomized controlled trial was conducted at the Department of Operative Dentistry and Endodontics, School of Dentistry, Islamabad, from May 15, 2023, to November 25, 2023. Participants (n = 60) with Class I and II primary carious lesions with a minimum cavity depth of 3-5 mm were randomly assigned to two groups (n = 30). After obtaining informed consent, the restorative procedure was accomplished using a minimally invasive approach and etch-and-rinse adhesive strategy. In group A, a nanofortified adhesive was used for composite restoration, whereas in group B, an adhesive without nanoparticles was used. Postoperative sensitivity was evaluated using the Visual Analog Scale (VAS) score at follow-up periods: of one day, one week, two weeks and one month. A Chi-square test was used to compare postoperative sensitivity between the two groups. The level of significance was set at p < 0.05. RESULTS: A noteworthy association was observed between sensitivity and the group variable at all four evaluation periods: after one day (p = 0.002), 1 week (p = 0.002), 2 weeks (p = 0.007) and one month. In conclusion, participants who underwent restorative intervention using titanium dioxide nanoreinforced adhesives reported a notable reduction in sensitivity at all time intervals. Hence, the occurrence and severity of postoperative sensitivity are significantly reduced using Bacillus subtilis-procured nanofortified adhesives as compared to conventional adhesives without nanoparticles. TRIAL REGISTRATION: This trial was retrospectively registered at ClinicalTrials.gov (ID: NCT06242184) on 03/02/2024. All procedures involving human participants were performed in conformance with this protocol.

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Recently, Pd catalysts supported on magnetic nanoparticles (MNPs) have attracted a great attention due to their ability of easy separation with an external magnet. Modification of MNPs is successfully used to obtain Pd magnetic catalysts with enhanced catalytic activity. In this work, we discussed the effect of titania content in TiO2/MNPs support materials on catalytic properties of Pd@TiO2/MNPs catalysts in phenylacetylene hydrogenation. TiO2/MNPs composites were prepared by simple ultrasound-assisted mixing of TiO2 and MNPs, synthesized by co-precipitation method. This was followed by deposition of palladium ions on the mixed metal oxides using NaOH as precipitant. The supports and catalysts were characterized using XRD, BET, STEM, EDX, XPS, and a SQUID magnetometer. Pd nanoparticles (5-6 nm) formed were found to be homogeneously distributed on support materials representing the well-mixed metal oxides with TiO2 content of 10, 30, 50, or 70%wt. Testing of the catalysts in phenylacetylene hydrogenation showed that their activity increased with increasing TiO2 content, and the process was faster in alkali medium (pH = 10). The hydrogenation rates of triple and double C-C bonds on Pd@70TiO2/MNPs achieved 9.3 × 10-6 mol/s and 23.1 × 10-6 mol/s, respectively, and selectivity to styrene was 96%. The catalyst can be easily recovered with an external magnet and reused for 12 runs without significant degradation in the catalytic activity. The improved catalytic properties of Pd@70TiO2/MNPs can be explained by the fact that the surface of the support is mainly composed of TiO2 particles, affecting the state and size of Pd species.

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Titanium dioxide (TiO2) is a prevalent food additive, yet comprehensive data on particle size and dietary exposure are lacking in China. Transmission electron microscopy results revealed that the quantitative proportion of nanoparticles (NPs) in food-additive TiO2 was 37.7%, with a mass fraction of 9.89%. Laboratory test results showed that among the domestic products surveyed, candies excluding gum-based candies contained the highest content of TiO2. Using consumption data from the China Health and Nutrition Survey in 2018, the average dietary exposure for TiO2 and TiO2 NPs in the Chinese population were calculated at 34.84 and 3.44 µg/kg bw/day, respectively. The primary dietary sources were puffed food and powdered drinks. Exposure varied significantly across age and region, with children and Inner Mongolia residents having the highest intake. TiO2 NP exposure showed a negative correlation with age. Despite this, the dietary exposure risk of TiO2 NPs for the Chinese population remains deemed acceptable.

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The incorporation of titanium dioxide nanoparticles into concrete blocks for paving adds photocatalytic functionality to the cementitious matrix, providing self-cleaning and pollutant-degrading properties. However, wear and leaching from these pavements can release potentially toxic compounds into water bodies, affecting aquatic organisms. In this context, this study evaluated the toxicological effects of leachates from photocatalytic concrete containing nano-TiO2 with an average size of 10 nm and anatase crystallinity on Daphnia magna. Acute and chronic toxicity tests on neonates were conducted with two leachate extracts: one from reference concrete and one from photocatalytic concrete (with 9% nano-TiO2 added by mass of cement). In terms of acute toxicity, the reference concrete extract had an EC50 of 104.0 mL/L at 48 h, whereas the concrete with TiO2 had an EC50 of 64.6 mL/L at 48 h. For chronic toxicity, the leachate from reference concrete had a significant effect (p < 0.05) on the size parameter with an LOEC of 4 mL/L, whereas the leachate from concrete with 9% nano-TiO2 did not have significant toxicological effects on any of the analyzed parameters (longevity, size, reproduction, and age of first posture) (LOEC > 6.5 mL/L). Furthermore, FTIR analysis indicated that TiO2 nanoparticles were not detected in the leachates, suggesting efficient anchoring within the cementitious matrix. The results indicate that there was no increase in the chronic toxicity of the leachate from the cementitious matrix when nanoparticles were added at a 9% mass ratio of cement.

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This study investigates the influence of LED radiation intensity on the photodeposition of gold nanoparticles onto TiO2 substrates, examining their physicochemical properties and photocatalytic activities. Utilizing a range of radiation intensities and wavelengths, TiO2-Au composites were synthesized and characterized through techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX), and X-ray photoelectron spectroscopy (XPS). The deposition process, markedly enhanced by shorter wavelengths and higher intensities, efficiently formed gold nanoparticles. This research distinctly highlights observable morphological changes in the nanoparticles; increased radiation intensity not only augmented the size but also altered their shape from spherical to hexagonal. These morphological transformations significantly improve the composites' light absorption and catalytic properties due to the surface plasmon resonance of the gold nanoparticles. Photocatalytic assessments, using metronidazole as a model pollutant, demonstrated that composites prepared with higher LED intensities showed significantly enhanced degradation capabilities compared to those synthesized with lower intensities. The findings underscore that manipulating photodeposition parameters can critically influence the structural and functional properties of TiO2-Au composites, potentially advancing their applications in environmental remediation and solar energy utilization.

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The nanoparticles (NPs) of metals and metal oxides constitute significant components of technology in terms of monometallic NPs (MNPs). Over the last decade, the most fascinating and in-depth uses of NPs have been found in the biomedical field, which has demonstrated the therapeutic potential of these particles. Significant strides have been made in the application of nanotechnology across various industries, including biomedical sciences. In biomedicine, two of the most important applications of NPs are in the diagnosis and treatment of disease. Given their ability to deliver specific drugs, these next-generation NPs provide safe and effective pharmacotherapies for a wide range of disorders. Selenium nanoparticles (SeNPs) and titanium dioxide (TiO2) NPs offer potential treatments for various applications, including hair care and cancer treatment. SeNPs help with abiotic stress, plant disease, and growth, while TiO2 NPs enhance bio-imaging and drug delivery. This comprehensive review focuses on MNPs like Se (metal-based) and TiO2 (metal-oxide based). It covers their synthesis methods, nanoscale physicochemical properties, and the definition of specific industrial applications in various fields of applied nanotechnology, including biomedicine.

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The inflammatory response to wear particles derived from hip prothesis is considered a hallmark of periprosthetic osteolysis, which can ultimately lead to the need for revision surgery. Exosomes (Exos) have been associated with various bone pathologies, and there is increasing recognition in the literature that they actively transport molecules throughout the body. The role of wear particles in osteoblast-derived Exos is unknown, and the potential contribution of Exos to osteoimmune communication and periprosthetic osteolysis niche is still in its infancy. Given this, we investigate how titanium dioxide nanoparticles (TiO2 NPs), similar in size and composition to prosthetic wear particles, affect Exos biogenesis. Two osteoblastic cell models commonly used to study the response of osteoblasts to wear particles were selected as a proof of concept. The contribution of Exos to periprosthetic osteolysis was assessed by functional assays in which primary human macrophages were stimulated with bone-derived Exos. We demonstrated that TiO2 NPs enter multivesicular bodies, the nascent of Exos, altering osteoblast-derived Exos secretion and molecular cargo. No significant differences were observed in Exos morphology and size. However, functional assays reveal that Exos cargo enriched in uPA stimulates macrophages to a mixed M1 and M2 phenotype, inducing the release of pro- and anti-inflammatory signals characteristic of periprosthetic osteolysis. In addition, we demonstrated the expression of uPA in exosomes derived from the urine of patients with osteolysis. These results suggest that uPA can be a potential biomarker of osteolysis. In the future, uPa may serve as a possible non-invasive biomarker to identify patients at risk for peri-implant osteolysis.

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Global climate change is a major trigger of unexpected temperature fluctuations. The impacts of marine heatwaves (MHWs) and nano-titanium dioxide (nano-TiO2) on marine organisms have been extensively investigated. However, the potential mechanisms underlying their interactive effects on physiological processes and metabolism remain poorly understood, especially regarding periodic MHWs in real-world conditions. In this study, the effects of nano-TiO2 (at concentrations of 0, 25, and 250 µg/L) and periodic MHWs on the condition index (CI) and underlying metabolic mechanisms were investigated in mussels (Mytilus coruscus). The results showed that mussels try to upregulate their respiration rate (RR) to enhance aerobic metabolism (indicated by elevated succinate dehydrogenase) under short-term nano-TiO2 exposure. However, even at ambient concentration (25 µg/L), prolonged nano-TiO2 exposure inhibited ingestion ability (decreased clearance rate) and glycolysis (inhibited pyruvate kinase, hexokinase, and phosphofructokinase activities), which led to an insufficient energy supply (decreased triglyceride, albumin, and ATP contents). Repeated thermal scenarios caused more severe physiological damage, demonstrating that mussels are fragile to periodic MHWs. MHWs decreased the zeta potential of the nano-TiO2 particles but increased the hydrodynamic diameter. Additionally, exposure to nano-TiO2 and periodic MHWs further affected aerobic respiration (inhibited lactate dehydrogenase and succinate dehydrogenase activities), metabolism (decreased RR, activities of respiratory metabolism-related enzymes, and expressions of PEPCK, PPARγ, and ACO), and overall health condition (decreased ATP and CI). These findings indicate that the combined stress of these two stressors exerts more detrimental impact on the physiological performance and energy metabolism of mussels, and periodic MHWs exacerbate the toxicological effects of ambient concentration nano-TiO2. Given the potential worsening of nanoparticle pollution and the increase in extreme heat events in the future, the well-being of mussels in the marine environment may face further threats.

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Perilla essential oil (PLEO) offers benefits for food preservation and healthcare, yet its instability restricts its applications. In this study, chitosan (CS) and TiO2 used to prepare composite particles. TiO2, after being modified with sodium laurate (SL), was successfully introduced at 0.1 %-3 % into the CS matrix. The resulting CS-SL-TiO2 composite particles can be formed by intertwining and rearranging through intramolecular and intermolecular interactions, and form an O/W interface with stability and viscoelasticity. The Pickering emulsions stabilized by these particles exhibit non-Newtonian pseudoplastic behavior, shear-thinning properties, and slow-release characteristics, along with antibacterial activity. Emulsions with 0.5 % and 1 % CS-SL-TiO2 composites demonstrated superior antibacterial effects against Escherichia coli and Staphylococcus aureus. The study revealed that all emulsions undergo Fickian diffusion and a sustained release of PLEO, with the Ritger-Peppas model best describing this release mechanism. The slow-release behaviors positively correlates with interfacial pressure, composite particle size, composite particle potential, composite contact angle, emulsion particle size and emulsion potential, but negatively correlates with diffusion rate, penetration rate, release kinetics and release rate. The findings lay groundwork for developing slow-release antimicrobial emulsions within polysaccharide matrices, showcasing promise for antimicrobial packaging solutions and enhanced food preservation techniques.

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In this work, the photo-, electro-, and photo-electro-oxidation of chloramphenicol was investigated. The photo-experiments were carried out with different irradiation sources (an ultraviolet and a simulated solar source) using self-doped titanium nanotubes (SDTNT), a very promising and innovative material that deserves further investigations in the degradation of different pollutants. The photo-electrooxidation (j = 15 mA cm-2) under simulated solar irradiation presented the best efficiency, with ca. 100% degradation and kinetic constant of k = 0.04427 min-1. The FTIR analysis demonstrated a structural modification of the standard molecule occurred for all conditions used, suggesting a modification in functional groups responsible for the biological activity. Furthermore, the TOC analysis showed a significant mineralization of the pollutant (66% from the initial concentration). In addition, both photo-electrooxidation approaches have demonstrated a positive value of S, where the simulated solar irradiation reached the highest value S = 0.6960. The experimental results pointed out evidence that the methodology employed herein for chloramphenicol degradation is greatly interesting and the photo-electrooxidation under simulated solar irradiation is a promising approach for this purpose.

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To investigate the carcinogenicity of anatase-type nano-titanium dioxide (aNTiO2), F344/DuCrlCrlj rats were exposed to aNTiO2 aerosol at concentrations of 0, 0.5, 2, and 8 mg/m3. The rats were divided into 2 groups: carcinogenicity study groups were exposed for two years, and satellite study groups were exposed for one year followed by recovery for 1 day, 26 weeks, and 52 weeks after the end of exposure. In the carcinogenicity groups, bronchiolo-alveolar carcinomas were observed in two 8 mg/m3-exposed males, showing an increasing trend by Peto's test. However, this incidence was at the upper limit of JBRC's historical control data. Bronchiolo-alveolar adenomas were observed in 1, 2, 3, and 4 rats of the 0, 0.5, 2, and 8 mg/m3-exposed females and were not statistically significant. However, the incidence in the 8 mg/m3-exposed females exceeded JBRC's historical control data. Therefore, we conclude there is equivocal evidence for the carcinogenicity of aNTiO2 in rats. No lung tumors were observed in the satellite groups. Particle-induced non-neoplastic lesions (alveolar epithelial hyperplasia and focal fibrosis) were observed in exposed males and females in both the carcinogenicity and satellite groups. Increased lung weight and neutrophils of bronchoalveolar lavage fluid were observed in the 8 mg/m3-exposed carcinogenicity groups. The aNTiO2 deposited in the lungs of the satellite group rats was decreased at 26 weeks after the end of exposure compared to 1 day after the end of exposure. At 52 weeks after the end of exposure, the decreased level was the same at 26 weeks after the end of exposure.

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BACKGROUND: In patients with coronary artery disease treated with permanent polymer-coated drug-eluting stents (DES), the persistent presence of a less biocompatible polymer might delay arterial healing. Thin strut polymer-free DES have the potential to improve clinical outcomes and reduce the duration of dual antiplatelet therapy (DAPT). The purpose of this first-in-human study was to assess the safety and effectiveness of a novel polymer-free DES in patients with de novo coronary lesions. The TIGERevolutioN® stent (CG Bio Co., Ltd., Seoul, Korea) consists of a cobalt chromium platform with a strut thickness of 70 µm and a surface treated with titanium dioxide onto which everolimus-eluting stent (EES) is applied abluminally (6 µg/mm of stent length) without utilization of a polymer. METHODS: A total of 20 patients were enrolled, with de novo coronary lesions (stable or unstable angina) and > 50% diameter stenosis in a vessel 2.25 to 4.00 mm in diameter and ≤ 40 mm in length for angiographic, optical coherence tomography (OCT), and clinical assessment at 8 months. All patients received DAPT after stent implantation. The primary endpoint was angiographic in-stent late lumen loss (LLL) at 8 months. RESULTS: Twenty patients with 20 lesions were treated with TIGERevolutioN®. At 8 months, in-stent LLL was 0.7 ± 0.4 mm. On OCT, percent area stenosis was 29.2 ± 9.4% and stent strut coverage was complete in all lesions. No adverse cardiovascular event occurred at 8 months. CONCLUSION: The new polymer-free EES was safe and effective with low LLL and excellent strut coverage at 8 months of follow-up. TRIAL REGISTRATION: Trial Registration: Clinical Research Information Service Identifier: KCT0005699.

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PURPOSE: Based on potential adverse health effects including genotoxicity concerns, the European Union banned titanium dioxide (TiO2) as a food additive in 2022, but food-grade TiO2 can still be used in pharmaceutical products. METHODS: This study described the presence of TiO2 in drugs available on the French market and estimated the population exposure to TiO2 through drug consumption. We used annual drug claim data aggregated at the national level together with data on the TiO2 content of pharmaceutical products available on the French market in 2001-2020. RESULTS: Of the 17 171 pharmaceutical specialties identified on the French market between 2001 and 2020, 38% contained TiO2. That figure reached 95% for capsules, 92% for film-coated tablets, 74% for coated tablets and 66% for soft capsules. Only 1% of non-oral specialties contained TiO2. The median TiO2 amount in one common dispensing unit was 1.5mg for oral specialties containing TiO2. We estimated that the mean exposure to TiO2 per inhabitant through the consumption of reimbursed drugs between 2012 and 2020 was 1.71mg per day, with women (1.81mg/d) slightly more exposed than men (1.54mg/d) and people older than 59 years (4.00mg/d) much more exposed than younger people (1.24 and 0.21mg/d for 20-59 and<20 years old individuals, respectively). CONCLUSION: This study highlights a widespread presence of TiO2 in drugs on the French market. The health impact of exposure to TiO2 through drug consumption should be evaluated in future epidemiological studies.

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BACKGROUND: The determination of (nano)particulate content from food additives has been a long-standing concern for authorities since it is of vital importance for ensuring food safety, regulatory adherence, and transparent consumer information. Nonetheless, a critical step in these determinations is the refinement of a careful and quantitative extraction process for particles that may be found within complex matrices such as confectionery products. The development of new technologies and analysis methods for nanoparticles is ongoing. Whereas new technologies and analysis methods for nanoparticles are being developed, the extraction of (nano)particles of different nature has not been adequately addressed in the literature. RESULTS: A simple aqueous extraction procedure was found to be suitable for the simultaneous extraction of TiO2 and SiO2 (nano)particles from five confectionery products. Neither the extraction agents (water, lipase, pancreatin and Tris-HCl solutions) nor the methods (manual shaking, ultrasonic bath, ultrasonic probe and ultrafiltration) altered the size, morphology, or aggregation state of either type of particle, as revealed by the micrographs obtained by Transmission Electron Microscopy (TEM). Single-particle ICP-MS (spICP-MS) determined that the optimal conditions for extracting both types of particles involve manual shaking using water as the solvent. Furthermore, the use of enzymes seemed to hinder the determination of both types of particles by spICP-MS. (Nano)particles of TiO2 and SiO2 were detected in all the confectionaries, even though the E171 additive was only labeled in one of them. The average percentage of nanoparticulate TiO2 material in the evaluated products was 30 %, while no nanometer-sized particles of SiO2 were detected. SIGNIFICANCE: Ensuring food safety, regulatory compliance and transparent consumer information relies on getting reliable results that connect with the application of sample treatment procedures for detecting unaltered nanoparticles in food products. The presented research introduces an economical, swift, user-friendly, environmentally responsible, and harmonious extraction method for the concurrent analysis of TiO2 and SiO2 particles in confectionery samples. Furthermore, particles from additives not included in the labeling have been detected, characterized, and quantified in the confectionary products.

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The use of metal oxide nanoparticles (NPs) in skincare products has significantly increased human skin exposure, raising safety concerns. Whilst NP's ability to penetrate healthy skin is minimal, studies have demonstrated that metal oxide NPs can induce toxicity in keratinocytes through direct contact. Moreover, NP's effect on common skin disorders like psoriasis, where barrier impairments and underlying inflammation could potentially increase NP penetration and worsen nanotoxicity is largely unstudied. In this paper, we investigated whether psoriasis-like human keratinocytes (Pso HKs) would exhibit heightened toxic responses to titanium dioxide (TiO2), zinc oxide (ZnO), and/or silica (SiO2) NPs compared to healthy HKs. Cells were exposed to each NP at concentrations ranging between 0.5 and 500 µg/ml for 6, 24, and 48 h. Amongst the metal oxide NPs, ZnO NPs produced the most pronounced toxic effects in both cell types, affecting cell viability, inducing oxidative stress, and activating the inflammasome pathway. Notably, only in ZnO NPs-treated Pso HKs, trappin-2/pre-elafin was cleaved intracellularly through a non-canonical process. In addition, tissue remodelling-related cytokines were upregulated in ZnO NP-treated Pso HKs. The full impact of the observed outcomes on psoriatic symptoms will need further evaluation. Nonetheless, our findings indicate the importance of understanding the sub-lethal impacts of NP exposures on keratinocytes, even though direct exposure may be low, particularly in the context of skin disorders where repeated and long-term exposures are anticipated.

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OBJECTIVE: Leaching of particles from dental titanium implant surfaces into preimplant microenvironment causes detrimental effects on bone cells. The current study investigated influence of simvastatin in mitigating adverse pro-inflammatory effects of titanium dioxide (TiO2) micro (MP) and nano (NP) particles on hFOB 1.19 cells in vitro. DESIGN: Viability of hFOB 1.19 cells following exposure to varying concentrations of TiO2 MPs and NPs and simvastatin were measured by XTT assay. hFOB 1.19 cells were treated with 100 µg/mL of TiO2 MPs, 100 µg/mL of TiO2 NPs, 0.1 µM simvastatin, 100 µg/mL of TiO2 MPs+ 0.1 µM simvastatin and 100 µg/mL of TiO2 NPs+ 0.1 µM simvastatin. After 24 h, ROS was measured by flow cytometry. On day 14, real-time PCR analysis for pro-inflammatory cytokines and bone formation markers was done for TNFα, IL1ß, osteocalcin, ALP, and Col1 markers; while ALP and RANKL/OPG ratio were determined by colorimetric and ELISA assays respectively. Further, mineralization study using Alizarin Red S staining (ARS) and calcium quantification were performed. RESULTS: Exposure of hFOB to TiO2 MPs and NPs generated ROS and reduced cell viability significantly, with upregulation of pro-inflammatory markers TNFα and IL1ß and downregulation of bone formation markers OC and increased RANKL/OPG ratio and lowered degree of mineralization. Treatment with 0.1 µM of simvastatin treatment reversed the effects by mitigating oxidative stress, dampening pro-inflammatory markers, upregulation of bone formation markers, lowering RANKL/OPG ratio and increasing degree of mineralization. CONCLUSION: Simvastatin possesses antioxidant, anti-inflammatory, and pro-osteogenic properties that may support bone healing around titanium implants.

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Food-grade titanium dioxide E171 was administered in feed to Sprague Dawley rats in an extended one-generation reproductive toxicity (EOGRT) study (OECD Test 443). The dosed diet (0, 100, 300, or 1000 mg/kg body weight/day) started 10 weeks before mating and continued throughout the study. After weaning, pups were allocated to Cohorts 1 A/1B (to assess reproductive toxicity), 2 A/2B (to assess developmental neurotoxicity), and 3 (to assess developmental immunotoxicity); in addition, Cohort 1B was mated to produce an F2 generation and satellite F0 animals were evaluated for colonic aberrant crypt foci (ACF). In F0 animals, there were no systemic toxicity or reproductive effects, no treatment-related histopathological changes, and no ACF in the colon. Serum estradiol or testosterone concentrations were not changed in F0 or F1 animals. No pre-/postnatal developmental changes related to treatment were noted in F1 animals, and the reproductive performance of F1 Cohort 1B animals was unaffected. F2 pups showed no abnormalities in pre- or postnatal development (postnatal days 4-8). No treatment-related developmental neurotoxicity was observed in Cohorts 2 A/2B. Although no treatment-related immunotoxicity was observed in Cohort 3, the positive control did not induce the expected response; this segment of the study will be repeated. Analyses of blood and urine showed negligible systemic absorption of E171 from the gastrointestinal tract upon dietary ingestion. The no observed adverse effect level (NOAEL) for parental systemic toxicity, reproductive toxicity, offspring toxicity, and developmental neurotoxicity was considered 1000 mg/kg body weight/day. For developmental immunotoxicity, a NOAEL was not determined owing to insufficient T-cell-dependent antibody response in the positive control. Our study provides robust data on the reproductive toxicity and preneoplastic potential of E171.

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Silica aerogels exhibit a unique nanostructure with low thermal conductivity and low density, making them attractive materials for thermal isolation under extreme conditions. The TiO2 particle is one of the common industrial additives used to reduce the thermal radiation of aerogel composites under high-temperature environments, but its influence on thermal resistance is almost unknown. Herein, we report the effect of TiO2 nanoparticles with different crystal phases and different sizes on the thermal stability of silica aerogel composites. By adding TiO2 nanoparticles, the aerogel can significantly resist collapse at high temperatures (up to 1000 °C). And compared with the rutile phase TiO2, the anatase phase TiO2 shows much higher temperature resistance performance, with shrinkage of only one-sixth of the rutile phase after 800 °C treatment. Interestingly, energy-dispersive spectrometer mapping results show that after 800 °C treatment, silica nanoparticles (NPs) are squeezed out in between anatase TiO2 particles, which resists the coarsening of silica NPs and ultimately enhances the stability of aerogel composites. The optimal anatase phase TiO2-doped silica aerogel demonstrates the integrated properties of crack-free morphology (2.84% shrinkage), low thermal conductivity (29.30 mW/(m·K)) and low density (149.4 mg/cm3) after 800 °C treatment. This study may provide new insights for developing oxide-doped silica aerogels with both high-temperature resistance and low thermal radiation.