scholarly journals Non-Resorbable Nanocomposite Membranes for Guided Bone Regeneration Based On Polysulfone-Quartz Fiber Grafted with Nano-TiO2

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 985 ◽  
Author(s):  
Gheorghe Nechifor ◽  
Eugenia Eftimie Totu ◽  
Aurelia Cristina Nechifor ◽  
Ibrahim Isildak ◽  
Ovidiu Oprea ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Bone Regeneration ◽  
Titanium Dioxide Nanoparticles ◽  
Composite Membranes ◽  
Chemical Oxidation ◽  
Guided Bone Regeneration ◽  
Inorganic Nanoparticles ◽  
Phase Method ◽  
Nanocomposite Membranes ◽  
Nano Tio2

The polymer-inorganic nanoparticles composite membranes are the latest solutions for multiple physicochemical resistance and selectivity requirements of membrane processes. This paper presents the production of polysulfone-silica microfiber grafted with titanium dioxide nanoparticles (PSf-SiO2-TiO2) composite membranes. Silica microfiber of length 150–200 μm and diameter 12–15 μm were grafted with titanium dioxide nanoparticles, which aggregated as microspheres of 1–3 μm, applying the sol-gel method. The SiO2 microfibers grafted with nano-TiO2 were used to prepare 12% polysulfone-based nanocomposite membranes in N-methyl pyrrolidone through the inversion phase method by evaporation. The obtained nanocomposite membranes, PSf-SiO2-TiO2, have flux characteristics, retention, mechanical characteristics, and chemical oxidation resistance superior to both the polysulfone integral polymer membranes and the PSf-SiO2 composite membranes. The antimicrobial tests highlighted the inhibitory effect of the PSf-SiO2-TiO2 composite membranes on five Gram (-) microorganisms and did not allow the proliferation of Candida albicans strain, proving that they are suitable for usage in the oral environment. The designed membrane met the required characteristics for application as a functional barrier in guided bone regeneration.

Carbon–titanium dioxide (C/TiO2) nanofiber composites for chemical oxidation of emerging organic contaminants in reactive filtration applications

2021 ◽  
Vol 8 (3) ◽  
pp. 711-722
Author(s):  
Katherine E. Greenstein ◽  
Matthew R. Nagorzanski ◽  
Bailey Kelsay ◽  
Edgard M. Verdugo ◽  
Nosang V. Myung ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Water Treatment ◽  
Organic Contaminants ◽  
Membrane Filtration ◽  
Titanium Dioxide Nanoparticles ◽  
Chemical Oxidation ◽  
Tio2 Nanofiber ◽  
System P ◽  
Filtration System ◽  
Emerging Organic Contaminants

Electrospun carbon nanofibers with integrated titanium dioxide nanoparticles are used for water treatment in a photoactive membrane filtration system.

scholarly journals Titanium Dioxide Nanoparticles Induced HeLa Cell Necrosis under UVA Radiation through the ROS-mPTP Pathway

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 2029
Author(s):  
Runqing Geng ◽  
Yuanyuan Ren ◽  
Rong Rao ◽  
Xi Tan ◽  
Hong Zhou ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Hela Cell ◽  
Hela Cells ◽  
Mitochondrial Permeability Transition ◽  
Titanium Dioxide Nanoparticles ◽  
Membrane Integrity ◽  
Permeability Transition ◽  
Cell Necrosis ◽  
Nano Tio2 ◽  
Uva Irradiation

Titanium dioxide nanoparticles (nano-TiO2), as a common nanomaterial, are widely used in water purification, paint, skincare and sunscreens. Its safety has always been a concern. Prior studies have shown that ultraviolet A (UVA) can exacerbate the toxicity of nano-TiO2, including inducing cell apoptosis, changing glycosylation levels, arresting cell cycle, inhibiting tumor cell and bacterial growth. However, whether the combination of UVA and nano-TiO2 cause cell necrosis and its mechanism are still rarely reported. In this study, we investigated the cytotoxicity and phototoxicity of mixture crystalline nano-TiO2 (25% rutile and 75% anatase, 21 nm) under UVA irradiation in HeLa cells. Our results showed that the abnormal membrane integrity and the ultrastructure of HeLa cells, together with the decreased viability induced by nano-TiO2 under UVA irradiation, were due to cell necrosis rather than caspase-dependent apoptosis. Furthermore, nano-TiO2 and UVA generated the reactive oxygen species (ROS) and caused the mitochondrial permeability transition pore (mPTP) of HeLa cells to abnormally open. Cell viability was significantly increased after adding vitamin C (VC) or cyclosporin A (CsA) individually to inhibit ROS and mPTP. Clearance of ROS could not only impede the opening of mPTP but also reduce the rate of cell necrosis. The results suggest the possible mechanism of HeLa cell necrosis caused by nano-TiO2 under UVA irradiation through the ROS-mPTP pathway.

The influence of titanium dioxide (TiO2) nanoparticles on the structure, optical and dielectric properties of polyvinyl chloride (PVC)

2020 ◽  
Vol 34 (28) ◽  
pp. 2050310
Author(s):  
M. A. Ramazanov ◽  
A. M. Rahimli ◽  
F. V. Hajiyeva
Keyword(s):  
Particle Size ◽  
Titanium Dioxide ◽  
Dielectric Properties ◽  
Surface Area ◽  
Titanium Dioxide Nanoparticles ◽  
Inorganic Nanoparticles ◽  
Nanocomposite Films ◽  
Slight Reduction ◽  
Insulation Systems ◽  
Nanoparticle Content

The tendency to improve the properties of insulating materials by incorporating inorganic nanoparticles has become necessary in order to design new insulation systems. In this study, PVC/TiO2-based nanocomposites with different loadings (3, 5 and 10 wt.%) of TiO2 nanoparticles were prepared by the solution mixing method. The morphology of the prepared nanocomposites was studied by Atomic Force Microscope (AFM). Experimentally, it was found that as the concentration increases, the size of the surface structural elements and particle size increases. Photoluminescence (PL) analysis of samples shows improvement compared to the pristine polymer. Furthermore, PL intensity for nanocomposites increases depending on the concentration and saturation occurs at a certain amount of titanium dioxide nanoparticles. The increase in luminescence intensity till a certain nanoparticle content is due to the growth of the luminescent surface area. Further saturation is explained by the increase in particle size with no increase or a slight reduction in surface area. Dielectric properties of nanocomposites were studied. It was found that dielectric permittivity of the materials increases as the nanoparticle volume content increases and it reaches at its highest value for the nanocomposites with 3% nanoparticle content. The optical properties of the polymer and nanocomposite films were studied in the region 200 nm to 600 nm. It was found that the PVC/TiO2 nanocomposites showed enhancement in the absorbance intensities which was more significant for the nanocomposites with higher nanoparticle content compared to the pristine polymer. Furthermore, absorption spectra were used to calculate the optical bandgap of the prepared nanocomposite films and redshift observed in the calculated values of bandgap for nanocomposites. Consequently, it was proved that by incorporating TiO2 nanoparticles into the polymer matrix, the spectral region of the samples can be expanded resulting in broadened application of such systems in various fields of science and technology.

Chitosan/nanohydroxyapatite composite membranes via dynamic filtration for guided bone regeneration

2008 ◽  
Vol 88A (3) ◽  
pp. 569-580 ◽  
Author(s):  
Shu‐Hua Teng ◽  
Eun‐Jung Lee ◽  
Byung‐Ho Yoon ◽  
Du‐Sik Shin ◽  
Hyoun‐Ee Kim ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Composite Membranes ◽  
Guided Bone Regeneration ◽  
Dynamic Filtration

scholarly journals Finding Nano: Challenges Involved in Monitoring the Presence and Fate of Engineered Titanium Dioxide Nanoparticles in Aquatic Environments

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 734
Author(s):  
Simone Heilgeist ◽  
Ryo Sekine ◽  
Oz Sahin ◽  
Rodney A. Stewart
Keyword(s):  
Titanium Dioxide ◽  
Tio2 Nanoparticles ◽  
Inductively Coupled Plasma ◽  
Titanium Dioxide Nanoparticles ◽  
Aqueous Media ◽  
Experimental Studies ◽  
Aquatic Environments ◽  
Nano Tio2 ◽  
Icp Ms ◽  
Modelling Studies

In recent years, titanium dioxide (TiO2) has increasingly been used as an inorganic ultraviolet (UV) filter for sun protection. However, nano-TiO2 may also pose risks to the health of humans and the environment. Thus, to adequately assess its potential adverse effects, a comprehensive understanding of the behaviour and fate of TiO2 in different environments is crucial. Advances in analytical and modelling methods continue to improve researchers’ ability to quantify and determine the state of nano-TiO2 in various environments. However, due to the complexity of environmental and nanoparticle factors and their interplay, this remains a challenging and poorly resolved feat. This paper aims to provide a focused summary of key particle and environmental characteristics that influence the behaviour and fate of sunscreen-derived TiO2 in swimming pool water and natural aquatic environments and to review the current state-of-the-art of single particle inductively coupled plasma mass spectrometry (SP-ICP-MS) approaches to detect and characterise TiO2 nanoparticles in aqueous media. Furthermore, it critically analyses the capability of existing fate and transport models to predict environmental TiO2 levels. Four particle and environmental key factors that govern the fate and behaviour of TiO2 in aqueous environments are identified. A comparison of SP-ICP-MS studies reveals that it remains challenging to detect and characterise engineered TiO2 nanoparticles in various matrices and highlights the need for the development of new SP-ICP-MS pre-treatment and analysis approaches. This review shows that modelling studies are an essential addition to experimental studies, but they still lack in spatial and temporal resolution and mostly exclude surface transformation processes. Finally, this study identifies the use of Bayesian Network-based models as an underexplored but promising modelling tool to overcome data uncertainties and incorporates interconnected variables.

scholarly journals Effects of Titanium Dioxide Nanoparticles on Photosynthetic and Antioxidative Processes of Scenedesmus obliquus

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1748
Author(s):  
Zhou Li ◽  
Philippe Juneau ◽  
Yingli Lian ◽  
Wei Zhang ◽  
Shanquan Wang ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Green Algae ◽  
Uv Light ◽  
Titanium Dioxide Nanoparticles ◽  
Scenedesmus Obliquus ◽  
Freshwater Ecosystems ◽  
Oxygen Species ◽  
Nano Tio2 ◽  
Titanium Dioxide Nanoparticle ◽  
Cell Membrane Disruption

The effects of the photocatalytic toxicity of titanium dioxide nanoparticle (nano-TiO2) on phytoplankton are well understood. However, as UV light intensity decreases sharply with the depth of the water column, the effects of nano-TiO2 itself on deeper water phytoplankton, such as green algae, need further research. In this research, we investigated the effects of three sizes of TiO2 (10, 50 and 200 nm) on the photosynthetic and antioxidative processes of Scenedesmus obliquus in the absence of UV light. We found that 50 nm and 10 nm TiO2 (10 mg/L) inhibited growth rates and the maximal photosystem II quantum yield compared to the control in Scenedesmus obliquus. The minimal and maximal fluorescence yields, and the contents of reactive oxygen species and lipid peroxidation, increased, indicating that photosynthetic energy/electrons transferred to oxygen and induced oxidative stress in nano-TiO2-treated samples. In addition, we found that aggregations of algae and 10 nm TiO2 were present, which could induce cell membrane disruption, and vacuoles were induced to cope with nano-TiO2 stress in Scenedesmus obliquus. These results enhance our understanding of the effects of nano-TiO2 on the photosynthetic and antioxidative processes of green algae, and provide basic information for evaluating the ecotoxicity of nano-TiO2 in freshwater ecosystems.

scholarly journals The Visible Photocatalytic Performance of Nano TiO2 and its Application for the Photodecomposition of Methanal

2021 ◽  
Vol 4 (6) ◽  
Author(s):  
Ma Tsz Hei Colby
Keyword(s):  
Titanium Dioxide ◽  
Free Radicals ◽  
Decomposition Rate ◽  
Photocatalytic Performance ◽  
Titanium Dioxide Nanoparticles ◽  
Water Source ◽  
Nano Tio2 ◽  
Supported Tio2

This project was conducted to investigate how to maximise the efficiency for photodecomposition based methanal scrubbers. The project focuses on using titanium dioxide Nanoparticles (NPs) in combination with chlorophyll (Chl) to achieve photodecomposition. In order to explore different factors that can affect the decomposition rate, namely, size of photocatalyst, temperature and phase of photocatalyst. It was found that a setup with solid supported TiO2 – Chlorophyll Nanoparticles is superior at decomposing methanal. Although inferior in terms of decomposition rate, TiO2 – Chlorophyll Nanoparticles suspended in 6:4 DMSO/H2O also has compelling advantages, specifically enforced contact between catalyst and methanal, and a higher water source to support the formation of free radicals.

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