Electrochemical behaviour of Ti/Al2O3/Ni nanocomposite material in artificial physiological solution: Prospects for biomedical application

Inorganic-based nanoelements such as nanoparticles (nanodots), nanopillars and nanowires, which have at least one dimension of 100 nm or less, have been extensively developed for biomedical applications. Furthermore, their properties can be varied by controlling such parameters as element shape, size, surface functionalization, and mutual interactions. In this study, Ni-alumina nanocomposite material was synthesized by the dc-Ni electrodeposition into a porous anodic alumina template (PAAT). The structural, morphological, and corrosion properties were studied using x-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and electrochemical techniques (linear sweep voltammetry). Template technology was used to obtain Ni nanopillars (NiNPs) in the PAAT nanocomposite. Low corrosion current densities (order of 0.5 μA/cm2) were indicators of this nanocomposite adequate corrosion resistance in artificial physiological solution (0.9% NaCl). A porous anodic alumina template is barely exposed to corrosion and performs protective functions in the composite. The results may be useful for the development of new nanocomposite materials technologies for a variety of biomedical applications including catalysis and nanoelectrodes for sensing and fuel cells. They are also applicable for various therapeutic purposes including targeting, diagnosis, magnetic hyperthermia, and drug delivery. Therefore, it is an ambitious task to research the corrosion resistance of these magnetic nanostructures in simulated body fluid. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.Government Council on Grants, Russian FederationBelarusian Republican Foundation for Fundamental Research, BRFFR: Ф18Д-00720163522Funding: The work was performed with support of State Scientific and Technical Program “Nanotech” (ГБЦ No 20163522), Belarusian Republican Foundation for Fundamental Research (Grant No. Ф18Д-007), Act 211 of Government of Russian Federation (contract No. 02.A03.21.0011). Additionally, the work was partially supported by the Grant of World Federation of Scientists (Geneva, Switzerland)

Electrochemical behaviour of Ti/Al2O3/Ni nanocomposite material in artificial physiological solution: Prospects for biomedical application

Inorganic-based nanoelements such as nanoparticles (nanodots), nanopillars and nanowires, which have at least one dimension of 100 nm or less, have been extensively developed for biomedical applications. Furthermore, their properties can be varied by controlling such parameters as element shape, size, surface functionalization, and mutual interactions. In this study, Ni-alumina nanocomposite material was synthesized by the dc-Ni electrodeposition into a porous anodic alumina template (PAAT). The structural, morphological, and corrosion properties were studied using x-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and electrochemical techniques (linear sweep voltammetry). Template technology was used to obtain Ni nanopillars (NiNPs) in the PAAT nanocomposite. Low corrosion current densities (order of 0.5 μA/cm2) were indicators of this nanocomposite adequate corrosion resistance in artificial physiological solution (0.9% NaCl). A porous anodic alumina template is barely exposed to corrosion and performs protective functions in the composite. The results may be useful for the development of new nanocomposite materials technologies for a variety of biomedical applications including catalysis and nanoelectrodes for sensing and fuel cells. They are also applicable for various therapeutic purposes including targeting, diagnosis, magnetic hyperthermia, and drug delivery. Therefore, it is an ambitious task to research the corrosion resistance of these magnetic nanostructures in simulated body fluid. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.Government Council on Grants, Russian FederationBelarusian Republican Foundation for Fundamental Research, BRFFR: Ф18Д-00720163522Funding: The work was performed with support of State Scientific and Technical Program “Nanotech” (ГБЦ No 20163522), Belarusian Republican Foundation for Fundamental Research (Grant No. Ф18Д-007), Act 211 of Government of Russian Federation (contract No. 02.A03.21.0011). Additionally, the work was partially supported by the Grant of World Federation of Scientists (Geneva, Switzerland)

Study of the Thermal Stability of Copper Contact Junctions in Si/SiO2 Substrates

The results of a comprehensive study of the structural- morphological and thermodynamic characteristics of the electrochemical precipitation of Cu in transition holes with a barrier layer of TiN in Si/SiO2 substrates by scanning electron microscopy (SEM) and differential thermal analysis (DTA) are presented. The temperature range that determines the heat resistance of copper (up to 750°C) and the temperature range (up to 886°C) that determines the thermal stability of the composite as a whole, as well as the ability to maintain the chemical composition and ordered structure at elevated temperatures, are found

Studying the Thermodynamic Properties of Composite Magnetic Material Based on Anodic Alumina

Magnetic nanoparticles based on Fe3O4 and their modifications of surface with therapeutic substances are of great interest, especially drug delivery for cancer therapy includes boron-neutron capture therapy. In this paper we study the thermodynamic, morphological, structural, and chemical properties of a composite material consisting of nickel nanowires (NWs) electrochemically deposited in the pores of the membrane of porous anodic aluminum oxide (PAA) by methods of differential thermal analysis (DTA), scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), and dispersive X-ray spectroscopy (EDX)

Magnetic Properties of the Densely Packed Ultra-Long Ni Nanowires Encapsulated in Alumina Membrane

High-quality and compact arrays of Ni nanowires with a high ratio (up to 700) were obtained by DC electrochemical deposition into porous anodic alumina membranes with a distance between pores equal to 105 nm. The nanowire arrays were examined using scanning electron microscopy, X-ray diffraction analysis and vibration magnetometry at 300 K and 4.2 K. Microscopic and X-ray diffraction results showed that Ni nanowires are homogeneous, with smooth walls and mostly single-crystalline materials with a 220-oriented growth direction. The magnetic properties of the samples (coercivity and squareness) depend more on the length of the nanowires and the packing factor (the volume fraction of the nanowires in the membrane). It is shown that the dipolar interaction changes the demagnetizing field during a reversal magnetization of the Ni nanowires, and the general effective field of magnetostatic uniaxial shape anisotropy. The effect of magnetostatic interaction between ultra-long nanowires (with an aspect ratio of >500) in samples with a packing factor of ≥37% leads to a reversal magnetization state, in which a “curling”-type model of nanowire behavior is realized. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: An.T. (Andrei Turutin) acknowledges the financial support of the Russian Science Foundation (Grant No. 19-79-30062) in part of the experimental work. A.K. (Alexander Kislyuk) and I.K. (Ilya Kubasov) acknowledge the financial support of the Ministry of Science and Higher Education of the Russian Federation as a part of the State Assignment (basic research, Project No. 0718-2020-0031 “New magnetoelectric composite materials based on oxide ferroelectrics having an ordered domain structure: production and properties”) in part of the XRD study

Magnetic Properties of the Densely Packed Ultra-Long Ni Nanowires Encapsulated in Alumina Membrane

High-quality and compact arrays of Ni nanowires with a high ratio (up to 700) were obtained by DC electrochemical deposition into porous anodic alumina membranes with a distance between pores equal to 105 nm. The nanowire arrays were examined using scanning electron microscopy, X-ray diffraction analysis and vibration magnetometry at 300 K and 4.2 K. Microscopic and X-ray diffraction results showed that Ni nanowires are homogeneous, with smooth walls and mostly single-crystalline materials with a 220-oriented growth direction. The magnetic properties of the samples (coercivity and squareness) depend more on the length of the nanowires and the packing factor (the volume fraction of the nanowires in the membrane). It is shown that the dipolar interaction changes the demagnetizing field during a reversal magnetization of the Ni nanowires, and the general effective field of magnetostatic uniaxial shape anisotropy. The effect of magnetostatic interaction between ultra-long nanowires (with an aspect ratio of >500) in samples with a packing factor of ≥37% leads to a reversal magnetization state, in which a “curling”-type model of nanowire behavior is realized. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: An.T. (Andrei Turutin) acknowledges the financial support of the Russian Science Foundation (Grant No. 19-79-30062) in part of the experimental work. A.K. (Alexander Kislyuk) and I.K. (Ilya Kubasov) acknowledge the financial support of the Ministry of Science and Higher Education of the Russian Federation as a part of the State Assignment (basic research, Project No. 0718-2020-0031 “New magnetoelectric composite materials based on oxide ferroelectrics having an ordered domain structure: production and properties”) in part of the XRD study

Helicobacter species are associated with possible increase in risk of biliary lithiasis and benign biliary diseases

<p>Abstract</p> <p>Background</p> <p>Hepato-biliary tract lithiasis is common and present either as pain or as asymptomatic on abdominal ultrasonography for other causes. Although the DNA of <it>Helicobacter </it>species are identified in the gallbladder bile, tissue or stones analyzed from these cases, still a causal relationship could not be established due to different results from different geographical parts.</p> <p>Methods</p> <p>A detailed search of pubmed and pubmedcentral was carried out with key words <it>Helicobacter </it>and gallbladder, gallstones, hepaticolithiasis, cholelithiasis and choledocholithiasis, benign biliary diseases, liver diseases. The data was entered in a data base and meta analysis was carried out. The analysis was carried out using odds ratio and a fixed effect model, 95% confidence intervals for odds ratio was calculated. Chi square test for heterogeneity was employed. The overall effect was calculated using Z test.</p> <p>Results</p> <p>A total of 12 articles were identified. One study used IgG for diagnosis while others used the PCR for Ure A gene, 16 S RNA or Cag A genes. A couple of studies used culture or histopathology besides the PCR. The cumulative results show a higher association of <it>Helicobacter </it>with chronic liver diseases (30.48%), and stone diseases (42.96%)(OR 1.77 95% CI 1.2–2.58; Z = 2.94, p = 0.003), the effect of each could not be identified as it was difficult to isolate the effect of helicobacter due to mixing of cases in each study.</p> <p>Conclusion</p> <p>The results of present meta analysis shows that there is a slight higher risk of cholelithiasis and benign liver disease (OR 1.77), however due to inherent inability to isolate the effect of stone disease from that of other benign lesions it is not possible to say for sure that <it>Helicobacter </it>has a casual relationship with benign biliary disease or stone disease or both.</p

Formation and corrosion properties of Ni-based composite material in the anodic alumina porous matrix

Ni nanopillars (Ni NPs) composite material formation technology embedded in porous anodic alumina by electrochemical deposition is presented in this paper. The morphological and structural properties of the composite material were investigated using scanning electron microscopy, atomic force microscopy, X-ray diffraction. The corrosion resistance of the nanocomposite materials has been studied by potentiodynamic polarization curves analysis and polarization resistance method. The composite represents the array of vertically ordered Ni NPs with the identical size in alumina matrix. XRD investigation indicates that Ni NPs are polynanocrystalline material with 18 nm crystallite size. It has been shown that Ni NPs and the composite material have sufficient corrosion resistance in a 0.9% aqueous NaCl solution. Porous alumina is the neutral and protective component of the composite. These nanocomposite materials can be excellent candidates for practical use in electronics, sensorics, biomedicine

Magnetic Properties of the Densely Packed Ultra-Long Ni Nanowires Encapsulated in Alumina Membrane

High-quality and compact arrays of Ni nanowires with a high ratio (up to 700) were obtained by DC electrochemical deposition into porous anodic alumina membranes with a distance between pores equal to 105 nm. The nanowire arrays were examined using scanning electron microscopy, X-ray diffraction analysis and vibration magnetometry at 300 K and 4.2 K. Microscopic and X-ray diffraction results showed that Ni nanowires are homogeneous, with smooth walls and mostly single-crystalline materials with a 220-oriented growth direction. The magnetic properties of the samples (coercivity and squareness) depend more on the length of the nanowires and the packing factor (the volume fraction of the nanowires in the membrane). It is shown that the dipolar interaction changes the demagnetizing field during a reversal magnetization of the Ni nanowires, and the general effective field of magnetostatic uniaxial shape anisotropy. The effect of magnetostatic interaction between ultra-long nanowires (with an aspect ratio of >500) in samples with a packing factor of ≥37% leads to a reversal magnetization state, in which a “curling”-type model of nanowire behavior is realized

Immobilization of boron-rich compound on Fe3O4 nanoparticles: Stability and cytotoxicity

Magnetic nanoparticles based on Fe3O4 and their modifications of surface with therapeutic substances are of great interest, especially drug delivery for cancer therapy includes boron-neutron capture therapy. The results of boron-rich compound (carborane borate) attachment to previously aminated by (3-aminopropyl)-trimethoxysilane iron oxide nanoparticles are presented. Energy-dispersive X-ray analysis and Fourier transform infrared spectroscopy with attenuated total reflection (ATR) accessory confirmed change of nanoparticles elemental content after modification and formation of new bond between Fe3O4 and attached molecules. Scanning and transmission electron microscopy showed that Fe3O4 nanoparticles average size is 18.9 nm. Phase parameters were investigated by powder X-ray diffraction, Fe3O4 nanoparticles magnetic behavior was evaluated by Mössbauer spectroscopy. Chemical and colloidal stability was studied using simulated body fluid (phosphate buffer – PBS). Modified nanoparticles have excellent stability in PBS (pH = 7.4), characterized by X-ray diffraction, Mössbauer spectroscopy and dynamic light scattering. Fe3O4 biocompatibility was elucidated in-vitro using cultured mouse embryonic fibroblasts. The obtained results show the increasing of IC50 from 0.110 mg/ml for Fe3O4 to 0.405 mg/ml for Fe3O4-Carborane nanoparticles. Obtained data confirm biocompatibility and stability of synthesized nanoparticles and potential to use them in boron-neutron capture therapy