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Colloids and Surfaces. B, Biointerfaces Dec 2022The research was focused on alternative treatment techniques, separating immediate and long-term reconstruction stages. The work involved development of ceramic...
The research was focused on alternative treatment techniques, separating immediate and long-term reconstruction stages. The work involved development of ceramic materials dedicated to reconstruction of the temporomandibular joint area. They were based on alumina (aluminum oxide) and characterized by varying porosities. A broad spectrum of studies was conducted to test the proposed material and determine its suitability for mandibular reconstruction. They compared the effects of substrate properties of ceramic materials in terms of biocompatibility, microbiology and systemic toxicity in in vivo studies. Finally it was concluded that Alumina LithaLox 350D is best suited for jawbone implants.
Topics: Humans; Ceramics; Aluminum Oxide; Bone and Bones; Anti-Bacterial Agents; Neoplasms; Materials Testing
PubMed: 36274400
DOI: 10.1016/j.colsurfb.2022.112943 -
Nanotoxicology Sep 2019Aluminum (Al) can be ingested from food and released from packaging and can reach key organs involved in human metabolism, including the liver via systemic distribution....
Aluminum (Al) can be ingested from food and released from packaging and can reach key organs involved in human metabolism, including the liver via systemic distribution. Recent studies discuss the occurrence of chemically distinct Al-species and their interconversion by contact with biological fluids. These Al species can vary with regard to their intestinal uptake, systemic transport, and therefore could have species-specific effects on different organs and tissues. This work aims to assess the hepatotoxic hazard potential of three different relevant Al species: soluble AlCl and two nanoparticulate Al species were applied, representing for the first time an investigation of metallic nanoparticles besides to mineral bound γ-AlO on hepatic cell lines. To investigate the uptake and toxicological properties of the Al species, we used two different human hepatic cell lines: HepG2 and differentiated HepaRG cells. Cellular uptake was determined by different methods including light microscopy, transmission electron microscopy, side-scatter analysis, and elemental analysis. Oxidative stress, mitochondrial dysfunction, cell death mechanisms, and DNA damage were monitored as cellular parameters. While cellular uptake into hepatic cell lines occurred predominantly in the particle form, only ionic AlCl caused cellular effects. Since it is known, that Al species can convert one into another, and mechanisms including 'trojan-horse'-like uptake can lead to an Al accumulation in the cells. This could result in the slow release of Al ions, for which reason further hazard cannot be excluded. Therefore, individual investigation of the different Al species is necessary to assess the toxicological potential of Al particles.
Topics: Aluminum Chloride; Aluminum Oxide; Biological Transport; Cell Survival; DNA Damage; Hep G2 Cells; Humans; Liver; Metal Nanoparticles; Microscopy, Electron, Transmission; Oxidative Stress
PubMed: 30938204
DOI: 10.1080/17435390.2019.1593542 -
Journal of Environmental Science and... 2021Measurement of skin exposure to particles using interception (e.g., cotton gloves) and removal (e.g., wiping) sampling techniques could be inaccurate because these...
Measurement of skin exposure to particles using interception (e.g., cotton gloves) and removal (e.g., wiping) sampling techniques could be inaccurate because these substrates do not have the same topography and adhesion characteristics as skin. The objective of this study was to compare particle transfer and adherence to cotton gloves, cotton gloves with artificial sebum, and a pre-moistened polyvinyl alcohol (PVA) material with bare human skin (fingertip, palm). Experiments were performed with aluminum oxide powder under standardized conditions for three types of surfaces touched, applied loads, contact times, and powder mass levels. In the final mixed model, the fixed effects of substrate, surface type, applied load, and powder mass and their significant two-way interaction terms explained 71% (transfer) and 74% (adherence) of the observed total variance in measurements. For particle mass transfer, compared with bare skin, bias was -77% (cotton glove with sebum) to +197% (PVA material) and for adherence bias ranged from -40% (cotton glove) to +428% (PVA material), which indicated under- and over-sampling by these substrates, respectively. Dermal exposure assessment would benefit from sampling substrates that better reflect human skin characteristics and more accurately estimate exposures. Mischaracterization of dermal exposure has important implications for exposure and risk assessment.
Topics: Adhesiveness; Aluminum Oxide; Cotton Fiber; Environmental Exposure; Humans; Polyvinyl Alcohol; Powders; Skin; Skin Absorption; Specimen Handling
PubMed: 33720803
DOI: 10.1080/10934529.2021.1899524 -
Clinical Oral Investigations Mar 2022To develop and test the cutting efficiency of a novel degradable glass as an alternative media to alumina powder for air abrasion.
OBJECTIVES
To develop and test the cutting efficiency of a novel degradable glass as an alternative media to alumina powder for air abrasion.
MATERIALS AND METHODS
A zinc-based glass (QMZK2) was designed, produced, and evaluated with a multi-modality imaging analysis. The glass dissolution study was carried out in three acids, using ICP-OES (inductively coupled plasma optical emission spectroscopy) at 5 different time points: 2.5, 5, 10, 60, and 240 min. The cutting efficiency of both materials was tested under the same parameters on slabs of elephant enamel. A stained fissure of a molar tooth was air abraded with the glass and evaluated with X-ray micro-tomography before and after air abrasion.
RESULTS
The particle size distribution of the glass was similar to that of alumina 53 µm but with a slightly greater dispersion of particle size. The shape of the particles was angular, appropriate for cutting purposes. The dissolution study showed that the glass dissolved rapidly in acidic conditions at all time points. Between the two variables, pressure and powder flow, pressure was found to influence the cutting speed to a greater extent than powder flow.
CONCLUSIONS
Alumina powder was found to perform significantly better in 4 of the 9 conditions tested on elephant enamel, QMZK2 in one, and no significant differences were found for the rest of the 4 conditions. The QMZK2 seems to offer promising results as an alternative material to alumina.
CLINICAL RELEVANCE
QMZK2 glass has the potential for replacing aluminum oxide as a degradable material in air abrasion technology.
Topics: Air Abrasion, Dental; Aluminum Oxide; Ceramics; Dental Enamel; Glass; Materials Testing; Powders; Surface Properties
PubMed: 34825281
DOI: 10.1007/s00784-021-04307-7 -
Biomatter 2013Zinc oxide (ZnO) is a widely used commercial material that is finding use in wound healing applications due to its antimicrobial properties. Our study demonstrates a...
Zinc oxide (ZnO) is a widely used commercial material that is finding use in wound healing applications due to its antimicrobial properties. Our study demonstrates a novel approach for coating ZnO with precise thickness control onto 20 nm and 100 nm pore diameter anodized aluminum oxide using atomic layer deposition (ALD). ZnO was deposited throughout the nanoporous structure of the anodized aluminum oxide membranes. An 8 nm-thick coating of ZnO, previously noted to have antimicrobial properties, was cytotoxic to cultured macrophages. After 48 h, ZnO-coated 20 nm and 100 nm pore anodized aluminum oxide significantly decreased cell viability by ≈65% and 54%, respectively, compared with cells grown on uncoated anodized aluminum oxide membranes and cells grown on tissue culture plates. Pore diameter (20-200 nm) did not influence cell viability.
Topics: Aluminum Oxide; Animals; Cell Survival; Coated Materials, Biocompatible; Dose-Response Relationship, Drug; Humans; Macrophages; Materials Testing; Membranes, Artificial; Microscopy, Electron, Scanning; Nanostructures; Surface Properties; Zinc Oxide
PubMed: 23881040
DOI: 10.4161/biom.25528 -
Proceedings of the National Academy of... Sep 2015Hierarchically designed structures with architectural features that span across multiple length scales are found in numerous hard biomaterials, like bone, wood, and...
Hierarchically designed structures with architectural features that span across multiple length scales are found in numerous hard biomaterials, like bone, wood, and glass sponge skeletons, as well as manmade structures, like the Eiffel Tower. It has been hypothesized that their mechanical robustness and damage tolerance stem from sophisticated ordering within the constituents, but the specific role of hierarchy remains to be fully described and understood. We apply the principles of hierarchical design to create structural metamaterials from three material systems: (i) polymer, (ii) hollow ceramic, and (iii) ceramic-polymer composites that are patterned into self-similar unit cells in a fractal-like geometry. In situ nanomechanical experiments revealed (i) a nearly theoretical scaling of structural strength and stiffness with relative density, which outperforms existing nonhierarchical nanolattices; (ii) recoverability, with hollow alumina samples recovering up to 98% of their original height after compression to ≥ 50% strain; (iii) suppression of brittle failure and structural instabilities in hollow ceramic hierarchical nanolattices; and (iv) a range of deformation mechanisms that can be tuned by changing the slenderness ratios of the beams. Additional levels of hierarchy beyond a second order did not increase the strength or stiffness, which suggests the existence of an optimal degree of hierarchy to amplify resilience. We developed a computational model that captures local stress distributions within the nanolattices under compression and explains some of the underlying deformation mechanisms as well as validates the measured effective stiffness to be interpreted as a metamaterial property.
Topics: Algorithms; Aluminum Oxide; Ceramics; Compressive Strength; Computer Simulation; Computer-Aided Design; Fractals; Hardness; Materials Testing; Nanostructures; Nanotechnology; Polymers; Stress, Mechanical; Tensile Strength
PubMed: 26330605
DOI: 10.1073/pnas.1509120112 -
Journal of Orthopaedic Surgery and... Mar 2023The objective of this prospective randomized monocentric study is to compare the speed and quality of interbody fusion of implanted porous AlO (aluminium oxide) cages... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
The objective of this prospective randomized monocentric study is to compare the speed and quality of interbody fusion of implanted porous AlO (aluminium oxide) cages with PEEK (polyetheretherketone) cages in ACDF (anterior cervical discectomy and fusion).
MATERIALS AND METHODS
A total of 111 patients were enrolled in the study, which was carried out between 2015 and 2021. The 18-month follow-up (FU) was completed in 68 patients with an AlO cage and 35 patients with a PEEK cage in one-level ACDF. Initially, the first evidence (initialization) of fusion was evaluated on computed tomography. Subsequently, interbody fusion was evaluated according to the fusion quality scale, fusion rate and incidence of subsidence.
RESULTS
Signs of incipient fusion at 3 months were detected in 22% of cases with the AlO cage and 37.1% with the PEEK cage. At 12-month FU, the fusion rate was 88.2% for AlO and 97.1% for PEEK cages, and at the final FU at 18 months, 92.6% and 100%, respectively. The incidence of subsidence was observed to be 11.8% and 22.9% of cases with AlO and PEEK cages, respectively.
CONCLUSIONS
Porous AlO cages demonstrated a lower speed and quality of fusion in comparison with PEEK cages. However, the fusion rate of AlO cages was within the range of published results for various cages. The incidence of subsidence of AlO cages was lower compared to published results. We consider the porous AlO cage as safe for a stand-alone disc replacement in ACDF.
Topics: Humans; Porosity; Prospective Studies; Diskectomy; Aluminum Oxide; Ketones; Polyethylene Glycols
PubMed: 36869376
DOI: 10.1186/s13018-023-03625-8 -
The Journal of Molecular Diagnostics :... Feb 2006A disposable 0.2-ml polymerase chain reaction (PCR) tube modified with an aluminum oxide membrane (AOM) has been developed for the extraction, amplification, and... (Comparative Study)
Comparative Study
A disposable 0.2-ml polymerase chain reaction (PCR) tube modified with an aluminum oxide membrane (AOM) has been developed for the extraction, amplification, and detection of nucleic acids. To assess the dynamic range of AOM tubes for real-time PCR, quantified herpes simplex virus (HSV) DNA was used to compare AOM tubes to standard PCR tubes. AOM PCR tubes used for amplification and detection of quantified HSV-1 displayed a crossing threshold (C(T)) shift 0.1 cycles greater than PCR tube controls. Experiments with HSV-1-positive cerebrospinal fluid (CSF) examined the extraction, amplification, and detection properties of the AOM tubes compared to the Qiagen DNA blood mini kit. The AOM extraction, amplification, and detection of HSV-1 in CSF displayed differences of less than one C(T) when compared to Qiagen-extracted samples. Experiments testing the AOM method using clinical CSF samples displayed 100% concordance with reported results. AOM tubes have no adverse effects on amplification or fluorescence acquisition by real-time PCR and can be effectively used for the extraction, amplification, and detection of HSV from CSF. The AOM single tube method is a fast, reliable, and reproducible technique for the extraction, amplification, and detection of HSV in CSF.
Topics: Aluminum Oxide; DNA, Viral; Humans; Nucleic Acid Amplification Techniques; Polymerase Chain Reaction; Polypropylenes; Simplexvirus
PubMed: 16436630
DOI: 10.2353/jmoldx.2006.040398 -
Dental Materials : Official Publication... Mar 2016This study evaluated the effect of addition of alumina particles (polycrystalline or monocrystalline), with or without silica coating, on the optical and mechanical...
OBJECTIVES
This study evaluated the effect of addition of alumina particles (polycrystalline or monocrystalline), with or without silica coating, on the optical and mechanical properties of a porcelain.
METHODS
Groups tested were: control (C), polycrystalline alumina (PA), polycrystalline alumina-silica (PAS), monocrystalline alumina (MA), monocrystalline alumina-silica (MAS). Polycrystalline alumina powder was synthesized using a polymeric precursor method; a commercially available monocrystalline alumina powder (sapphire) was acquired. Silica coating was obtained by immersing alumina powders in a tetraethylorthosilicate solution, followed by heat-treatment. Electrostatic stable suspension method was used to ensure homogenous dispersion of the alumina particles within the porcelain powder. The ceramic specimens were obtained by heat-pressing. Microstructure, translucency parameter, contrast ratio, opalescence index, porosity, biaxial flexural strength, roughness, and elastic constants were characterized.
RESULTS
A better interaction between glass matrix and silica coated crystalline particles is suggested in some analyses, yet further investigation is needed to confirm it. The materials did not present significant differences in biaxial flexural strength, due to the presence of higher porosity in the groups with alumina addition. Elastic modulus was higher for MA and MAS groups. Also, these were the groups with optical qualities and roughness closer to control. The PA and PAS groups were considerably more opaque as well as rougher.
SIGNIFICANCE
Porcelains with addition of monocrystalline particles presented superior esthetic qualities compared to those with polycrystalline particles. In order to eliminate the porosity in the ceramic materials investigated herein, processing parameters need to be optimized as well as different glass frites should be tested.
Topics: Aluminum Oxide; Ceramics; Coated Materials, Biocompatible; Crystallization; Dental Porcelain; Dental Stress Analysis; Hot Temperature; Materials Testing; Particle Size; Pliability; Porosity; Surface Properties
PubMed: 26754431
DOI: 10.1016/j.dental.2015.12.009 -
Sensors (Basel, Switzerland) Jul 2014Electrochemical anodization of pure aluminum enables the growth of highly ordered nanoporous anodic alumina (NAA) structures. This has made NAA one of the most popular... (Review)
Review
Electrochemical anodization of pure aluminum enables the growth of highly ordered nanoporous anodic alumina (NAA) structures. This has made NAA one of the most popular nanomaterials with applications including molecular separation, catalysis, photonics, optoelectronics, sensing, drug delivery, and template synthesis. Over the past decades, the ability to engineer the structure and surface chemistry of NAA and its optical properties has led to the establishment of distinctive photonic structures that can be explored for developing low-cost, portable, rapid-response and highly sensitive sensing devices in combination with surface plasmon resonance (SPR) and reflective interference spectroscopy (RIfS) techniques. This review article highlights the recent advances on fabrication, surface modification and structural engineering of NAA and its application and performance as a platform for SPR- and RIfS-based sensing and biosensing devices.
Topics: Aluminum Oxide; Biosensing Techniques; Equipment Design; Equipment Failure Analysis; Interferometry; Metal Nanoparticles; Nanopores; Surface Plasmon Resonance; Surface Properties; Transducers
PubMed: 25004150
DOI: 10.3390/s140711878