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Neurotoxicology Mar 2021
Topics: Aluminum Compounds; Aluminum Hydroxide; Aluminum Oxide; Alzheimer Disease; Animals; Humans; Risk Assessment; Toxicity Tests; Water Pollutants, Chemical
PubMed: 33278452
DOI: 10.1016/j.neuro.2020.12.001 -
Physiological Research Nov 2022Nanomaterials or nanoparticles are commonly used in the cosmetics, medicine, and food industries. Many researchers studied the possible side effects of several...
Nanomaterials or nanoparticles are commonly used in the cosmetics, medicine, and food industries. Many researchers studied the possible side effects of several nanoparticles including aluminum oxide (Al2O3-nps) and zinc oxide nanoparticles (ZnO-nps). Although, there is limited information available on their direct or side effects, especially on the brain, heart, and lung functions. This study aimed to investigate the neurotoxicity, cardiotoxicity, and lung toxicity induced by Al2O3-nps and ZnO-nps or in combination via studying changes in gene expression, alteration in cytokine production, tumor suppressor protein p53, neurotransmitters, oxidative stress, and the histological and morphological changes. Obtained results showed that Al2O3-nps, ZnO-nps and their combination cause an increase in 8-hydroxy-2´-deoxyguanosine (8-OHdG), cytokines, p53, oxidative stress, creatine kinase, norepinephrine, acetylcholine (ACh), and lipid profile. Moreover, significant changes in the gene expression of mitochondrial transcription factor-A (mtTFA) and peroxisome proliferator activator receptor-gamma-coactivator-1alpha (PGC-1alpha) were also noted. On the other hand, a significant decrease in the levels of antioxidant enzymes, total antioxidant capacity (TAC), reduced glutathione (GSH), paraoxonase 1 (PON1), neurotransmitters (dopamine - DA, and serotonin - SER), and the activity of acetylcholine esterase (AChE) in the brain, heart, and lung were found. Additionally, these results were confirmed by histological examinations. The present study revealed that the toxic effects were more when these nanoparticle doses are used in combination. Thus, Al2O3-nps and ZnO-nps may behave as neurotoxic, cardiotoxic, and lung toxic, especially upon exposure to rats in combination.
Topics: Animals; Rats; Zinc Oxide; Aluminum Oxide; Antioxidants; Acetylcholine; Oxidative Stress; Lung; Nanoparticles; Brain; Metal Nanoparticles
PubMed: 36121020
DOI: 10.33549/physiolres.934831 -
International Journal of Pharmaceutics Sep 2021The use of inorganic nanoparticles (NPs) gains interest for pharmaceutical applications, e.g. as adjuvants or drug delivery vehicles. Colloidal stability of NPs in...
The use of inorganic nanoparticles (NPs) gains interest for pharmaceutical applications, e.g. as adjuvants or drug delivery vehicles. Colloidal stability of NPs in aqueous suspensions is a major development challenge. Both frozen and lyophilized liquids are alternative presentations to liquid dispersion. To improve the basic understanding, we investigated the freeze-thawing stability of model α-AlO NPs. Freeze-thawing was conducted in three different buffer types at pH5 and 8 without and with additives to determine fundamental formulation principles. Before freeze-thawing, α-AlO NPs could be stabilized in sodium citrate buffer at pH5 and 8, and in sodium or potassium phosphate at pH8. Particles revealed low zeta potential values in phosphate buffers at pH5 indicating insufficient electrostatic stabilization. After freeze-thawing, an increase in NP size was strongly reduced in potassium phosphate and sodium citrate buffers. Subsequent pH measurements upon freezing revealed a drastic acidic pH shift in sodium phosphate which was further demonstrated to destabilize NPs. The ionic stabilizers gelatin A/B, Na-CMC, and SDS, were suitable to improve colloidal stability in phosphate buffers at pH5 highlighting the importance of charge stabilization. Freeze-thawing stability was best in presence of gelatin A/B, followed by PVA, mannitol, or sucrose. Depletion and steric stabilization were insufficient using PEG and surfactants respectively. Thus, we could identify the fundamental formulation principles to preserve inorganic NPs upon freezing: i) sufficient charge stabilization, ii) a maintained pH during freezing, and iii) the addition of a suitable stabilizer, preferably gelatin, not necessarily surfactants. This forms the basis for future studies, e.g. on lyophilization.
Topics: Aluminum Oxide; Drug Stability; Excipients; Freeze Drying; Freezing; Nanoparticles
PubMed: 34310956
DOI: 10.1016/j.ijpharm.2021.120932 -
Scientific Reports Feb 2020The knowledge about a potential in vivo uptake and subsequent toxicological effects of aluminum (Al), especially in the nanoparticulate form, is still limited. This...
The knowledge about a potential in vivo uptake and subsequent toxicological effects of aluminum (Al), especially in the nanoparticulate form, is still limited. This paper focuses on a three day oral gavage study with three different Al species in Sprague Dawley rats. The Al amount was investigated in major organs in order to determine the oral bioavailability and distribution. Al-containing nanoparticles (NMs composed of Al and aluminum oxide (AlO)) were administered at three different concentrations and soluble aluminum chloride (AlCl·6HO) was used as a reference control at one concentration. A microwave assisted acid digestion approach followed by inductively coupled plasma mass spectrometry (ICP-MS) analysis was developed to analyse the Al burden of individual organs. Special attention was paid on how the sample matrix affected the calibration procedure. After 3 days exposure, AlCl·6HO treated animals showed high Al levels in liver and intestine, while upon treatment with Al NMs significant amounts of Al were detected only in the latter. In contrast, following AlO NMs treatment, Al was detected in all investigated organs with particular high concentrations in the spleen. A rapid absorption and systemic distribution of all three Al forms tested were found after 3-day oral exposure. The identified differences between Al and AlO NMs point out that both, particle shape and surface composition could be key factors for Al biodistribution and accumulation.
Topics: Administration, Oral; Aluminum; Aluminum Chloride; Aluminum Oxide; Animals; Biological Availability; Humans; Intestines; Liver; Nanostructures; Rats; Rats, Sprague-Dawley; Spleen; Tissue Distribution
PubMed: 32060369
DOI: 10.1038/s41598-020-59710-z -
Dalton Transactions (Cambridge, England... Jan 2023There have been numerous applications of supercapacitors in day-to-day life. Along with batteries and fuel cells, supercapacitors play an essential role in supplementary... (Review)
Review
There have been numerous applications of supercapacitors in day-to-day life. Along with batteries and fuel cells, supercapacitors play an essential role in supplementary electrochemical energy storage technologies. They are used as power sources in portable electronics, automobiles, power backup, medical equipment, . Among various working electrode materials explored for supercapacitors, nanostructured transition metal oxides containing mixed metals are highly specific and special, because of their stability, variable oxidation states of the constituted metal ions, possibility to tune the mixed metal combinations, and existence of new battery types and extrinsic pseudocapacitance. This review presents the key features and recent developments in the direction of synthesis and electrochemical energy storage behavior of some of the recent morphology-oriented transition metal oxide and mixed transition metal oxide nanoparticles. We also targeted the studies on a few of the recently developed flexible and bendable supercapacitor devices based on these mixed transition metal oxides.
Topics: Oxides; Nanostructures; Aluminum Oxide; Magnesium Oxide; Metals
PubMed: 36541048
DOI: 10.1039/d2dt02733j -
Journal of Environmental Management Nov 2023Aluminum is an important lightweight and high-value metal that is widely used in the transportation, construction, and military industries. China is the largest producer... (Review)
Review
Aluminum is an important lightweight and high-value metal that is widely used in the transportation, construction, and military industries. China is the largest producer of Al in the world, and vast quantities of Al dross (ash) are generated and stored every year. Aluminum dross contains fluoride and heavy metals, and easily reacts with water and acid to produce stimulating, toxic, and explosive gases. Owing to a lack of developed technologies, most of this dross cannot be safely treated, resulting in a waste of resources and serious environmental and ecological risks. This review briefly describes the distribution and proportions of bauxite deposits in China, the Al extraction process, and the hazardous solid waste that is generated. It also discusses the comprehensive treatments for Al dross, including the hydrometallurgy and pyrometallurgy recovery processes, and reuse of Al, AlO, SiO, and chloride salts as a summarized comparison of their advantages and disadvantages. In particular, this review focuses on the efforts to analyze the relationship between existing processes and the attempts to establish a comprehensive technology to treat Al dross. Additionally, areas for future research are suggested, which may provide new ideas for the closed-loop treatment of Al dross.
Topics: Aluminum; Silicon Dioxide; Metals; Aluminum Oxide; China
PubMed: 37451029
DOI: 10.1016/j.jenvman.2023.118575 -
International Journal of Molecular... Mar 2023We report on theoretical investigations of a methylammonium lead halide perovskite system loaded with iron oxide and aluminum zinc oxide (ZnO:Al/MAPbI3/Fe2O3) as a...
We report on theoretical investigations of a methylammonium lead halide perovskite system loaded with iron oxide and aluminum zinc oxide (ZnO:Al/MAPbI3/Fe2O3) as a potential photocatalyst. When excited with visible light, this heterostructure is demonstrated to achieve a high hydrogen production yield via a z-scheme photocatalysis mechanism. The Fe2O3: MAPbI3 heterojunction plays the role of an electron donor, favoring the hydrogen evolution reaction (HER), and the ZnO:Al compound acts as a shield against ions, preventing the surface degradation of MAPbI3 during the reaction, hence improving the charge transfer in the electrolyte. Moreover, our findings indicate that the ZnO:Al/MAPbI3 heterostructure effectively enhances electrons/holes separation and reduces their recombination, which drastically improves the photocatalytic activity. Based on our calculations, our heterostructure yields a high hydrogen production rate, estimated to be 265.05 μmol/g and 362.99 μmol/g, respectively, for a neutral pH and an acidic pH of 5. These theoretical yield values are very promising and provide interesting inputs for the development of stable halide perovskites known for their superlative photocatalytic properties.
Topics: Zinc Oxide; Ferric Compounds; Zinc; Aluminum Oxide; Hydrogen
PubMed: 36902284
DOI: 10.3390/ijms24054856 -
Biosensors Jul 2023Interferometry-based, reflectometric, label-free biosensors have made significant progress in the analysis of molecular interactions after years of development. The... (Review)
Review
Interferometry-based, reflectometric, label-free biosensors have made significant progress in the analysis of molecular interactions after years of development. The design of interference substrates is a key research topic for these biosensors, and many studies have focused on porous films prepared by top-down methods such as porous silicon and anodic aluminum oxide. Lately, more research has been conducted on ordered porous layer interferometry (OPLI), which uses ordered porous colloidal crystal films as interference substrates. These films are made using self-assembly techniques, which is the bottom-up approach. They also offer several advantages for biosensing applications, such as budget cost, adjustable porosity, and high structural consistency. This review will briefly explain the fundamental components of self-assembled materials and thoroughly discuss various self-assembly techniques in depth. We will also summarize the latest studies that used the OPLI technique for label-free biosensing applications and divide them into several aspects for further discussion. Then, we will comprehensively evaluate the strengths and weaknesses of self-assembly techniques and discuss possible future research directions. Finally, we will outlook the upcoming challenges and opportunities for label-free biosensing using the OPLI technique.
Topics: Porosity; Interferometry; Biosensing Techniques; Silicon; Aluminum Oxide
PubMed: 37504128
DOI: 10.3390/bios13070730 -
Molecules (Basel, Switzerland) Jan 2023In this article, we describe the antimicrobial properties of pristine anodised aluminium oxide matrices-the material many consider biologically inert. During a typical...
In this article, we describe the antimicrobial properties of pristine anodised aluminium oxide matrices-the material many consider biologically inert. During a typical anodisation process, chromium and chlorine compounds are used for electropolishing and the removal of the first-step aluminium oxide. Matrices without the use of those harmful compounds were also fabricated and tested for comparison. The antibacterial tests were conducted on four strains of : K12, R2, R3 and R4. The properties of the matrices were also compared to the three types of antibiotics: ciprofloxacin, bleomycin and cloxacillin using the Minimal Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) tests. Moreover, DNA was isolated from the analysed bacteria which was additionally digested with formamidopyrimidine-DNA glycosylase (Fpg) protein from the group of repair glycosases. These enzymes are markers of modified oxidised bases in nucleic acids produced during oxidative stress in cells. Preliminary cellular studies, MIC and MBC tests and digestion with Fpg protein after modification of bacterial DNA suggest that these compounds may have greater potential as antibacterial agents than the aforementioned antibiotics. The described composites are highly specific for the analysed model strains and may be used in the future as new substitutes for commonly used antibiotics in clinical and nosocomial infections in the progressing pandemic era. The results show much stronger antibacterial properties of the functionalised membranes on the action of bacterial membranes in comparison to the antibiotics in the Fpg digestion experiment. This is most likely due to the strong induction of oxidative stress in the cell through the breakdown of the analysed bacterial DNA.
Topics: DNA Repair; Escherichia coli Proteins; Aluminum; DNA, Bacterial; Oxides; DNA-Formamidopyrimidine Glycosylase; Escherichia coli; Anti-Bacterial Agents; Aluminum Oxide
PubMed: 36615599
DOI: 10.3390/molecules28010401 -
Plant Physiology and Biochemistry : PPB Feb 2021Aluminum oxide (AlO) nanoparticles (NPs) are among the nanoparticles most used industrially, but their impacts on living organisms are widely unknown. We evaluated the...
Aluminum oxide (AlO) nanoparticles (NPs) are among the nanoparticles most used industrially, but their impacts on living organisms are widely unknown. We evaluated the effects of 50-1000 mg L AlO NPs on the growth, metabolism of lignin and its monomeric composition in soybean plants. AlO NPs did not affect the length of roots and stems. However, at the microscopic level, AlO NPs altered the root surface inducing the formation of cracks near to root apexes and damage to the root cap. The results suggest that AlO NPs were internalized and accumulated into the cytosol and cell wall of roots, probably interacting with organelles such as mitochondria. At the metabolic level, AlO NPs increased soluble and cell wall-bound peroxidase activities in roots and stems but reduced phenylalanine ammonia-lyase activity in stems. Increased lignin contents were also detected in roots and stems. The AlO NPs increased the p-hydroxyphenyl monomer levels in stems but reduced them in roots. The total phenolic content increased in roots and stems; cell wall-esterified p-coumaric and ferulic acids increased in roots, while the content of p-coumaric acid decreased in stems. In roots, the content of ionic aluminum (Al) was extremely low, corresponding to 0.0000252% of the aluminum applied in the nanoparticulate form. This finding suggests that all adverse effects observed were due to the AlO NPs only. Altogether, these findings suggest that the structure and properties of the soybean cell wall were altered by the AlO NPs, probably to reduce its uptake and phytotoxicity.
Topics: Aluminum Oxide; Cell Wall; Lignin; Nanoparticles; Glycine max
PubMed: 33429191
DOI: 10.1016/j.plaphy.2020.12.028