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Inhibition of ice growth and recrystallization by zirconium acetate and zirconium acetate hydroxide.PloS One 2013The control over ice crystal growth, melting, and shaping is important in a variety of fields, including cell and food preservation and ice templating for the production...
The control over ice crystal growth, melting, and shaping is important in a variety of fields, including cell and food preservation and ice templating for the production of composite materials. Control over ice growth remains a challenge in industry, and the demand for new cryoprotectants is high. Naturally occurring cryoprotectants, such as antifreeze proteins (AFPs), present one solution for modulating ice crystal growth; however, the production of AFPs is expensive and inefficient. These obstacles can be overcome by identifying synthetic substitutes with similar AFP properties. Zirconium acetate (ZRA) was recently found to induce the formation of hexagonal cavities in materials prepared by ice templating. Here, we continue this line of study and examine the effects of ZRA and a related compound, zirconium acetate hydroxide (ZRAH), on ice growth, shaping, and recrystallization. We found that the growth rate of ice crystals was significantly reduced in the presence of ZRA and ZRAH, and that solutions containing these compounds display a small degree of thermal hysteresis, depending on the solution pH. The compounds were found to inhibit recrystallization in a manner similar to that observed in the presence of AFPs. The favorable properties of ZRA and ZRAH suggest tremendous potential utility in industrial applications.
Topics: Acetates; Cryoprotective Agents; Crystallization; Ice; Temperature; Zirconium
PubMed: 23555701
DOI: 10.1371/journal.pone.0059540 -
Bioconjugate Chemistry Jul 2021Immuno-PET using desferrioxamine (DFO)-conjugated zirconium-89 ([Zr]Zr)-labeled antibodies is a powerful tool used for preclinical and clinical molecular imaging....
Immuno-PET using desferrioxamine (DFO)-conjugated zirconium-89 ([Zr]Zr)-labeled antibodies is a powerful tool used for preclinical and clinical molecular imaging. However, a comprehensive study evaluating the variables involved in DFO-conjugation and Zr-radiolabeling of antibodies and their impact on the and behavior of the resulting radioimmunoconjugates has not been adequately performed. Here, we synthesized different DFO-conjugates of the HER2-targeting antibody (Ab)-trastuzumab, dubbed T5, T10, T20, T60, and T200-to indicate the molar equivalents of DFO used for bioconjugation. Next we radiolabeled the immunoconjugates with ([Zr]Zr) under a comprehensive set of reaction conditions including different buffers (PBS, chelexed-PBS, TRIS/HCl, HEPES; ± radioprotectants), different reaction volumes (0.1-1 mL), variable amounts of DFO-conjugated Ab (5, 25, 50 μg), and radioactivity (0.2-1.0 mCi; 7.4-37 MBq). We evaluated the effects of these variables on radiochemical yield (RCY), molar activity ()/specific activity (), immunoreactive fraction, and ultimately the biodistribution profile and tumor targeting ability of the trastuzumab radioimmunoconjugates. We show that increasing the degree of DFO conjugation to trastuzumab increased the RCY (∼90%) and / (∼194 MBq/nmol; 35 mCi/mg) but decreased the HER2-binding affinity (3.5×-4.6×) and the immunoreactive fraction of trastuzumab down to 50-64%, which translated to dramatically inferior performance of the radioimmunoconjugate. Cell-based immunoreactivity assays and standard binding affinity analyses using surface plasmon resonance (SPR) did not predict the poor performance of the most extreme T200 conjugate. However, SPR-based concentration free calibration analysis yielded active antibody concentration and was predictive of the trends. Positron emission tomography (PET) imaging and biodistribution studies in a HER2-positive xenograft model revealed activity concentrations of 38.7 ± 3.8 %ID/g in the tumor and 6.3 ± 4.1 %ID/g in the liver for ([Zr]Zr)-T5 (∼1.4 ± 0.5 DFOs/Ab) at 120 h after injection of the radioimmunoconjugates. On the other hand, ([Zr]Zr)-T200 (10.9 ± 0.7 DFOs/Ab) yielded 16.2 ± 3.2 %ID/g in the tumor versus 27.5 ± 4.1 %ID/g in the liver. Collectively, our findings suggest that synthesizing trastuzumab immunoconjugates bearing 1-3 DFOs per Ab (T5 and T10) combined with radiolabeling performed in low reaction volumes using Chelex treated PBS or HEPEs without a radioprotectant provided radioimmunoconjugates having high / (97 MBq/nmol; 17.5 ± 2.2 mCi/mg), highly preserved immunoreactive fractions (86-93%), and favorable biodistribution profile with excellent tumor uptake.
Topics: Antibodies; Immunoconjugates; Positron-Emission Tomography; Radioisotopes; Zirconium
PubMed: 32197571
DOI: 10.1021/acs.bioconjchem.0c00087 -
Nanotheranostics 2021With the rapid development of anti-cancer cell-based therapies, such as adoptive T cell therapies using tumor-infiltrating T cells, T cell receptor transduced T cells,... (Review)
Review
With the rapid development of anti-cancer cell-based therapies, such as adoptive T cell therapies using tumor-infiltrating T cells, T cell receptor transduced T cells, and chimeric antigen receptor T cells, there has been a growing interest in imaging technologies to non-invasively track transferred cells . Cell tracking using cell labeling with positron emitting radioisotopes for positron emission tomography (PET) imaging has potential advantages over single-photon emitting radioisotopes. These advantages include intrinsically higher resolution, higher sensitivity, and higher signal-to-background ratios. Here, we review the current status of recently developed Zirconium-89 (Zr)-oxine cell labeling with PET imaging focusing on its applications and future perspectives. Labeling of cells with Zr-oxine is completed in a series of relatively simple steps, and its low radioactivity doses required for imaging does not interfere with the proliferation or function of the labeled immune cells. Preclinical studies have revealed that Zr-oxine PET allows high-resolution tracking of labeled cells for 1-2 weeks after cell transfer both in mice and non-human primates. These results provide a strong rationale for the clinical translation of Zr-oxine PET-based imaging of cell-based therapy.
Topics: Animals; Humans; Mice; Oxyquinoline; Positron-Emission Tomography; Radioisotopes; Zirconium
PubMed: 33391973
DOI: 10.7150/ntno.51391 -
Journal of Indian Prosthodontic Society 2022The aim of the study is to systematically assess the impact of low-temperature degradation (LTD) simulation in an autoclave on mechanical and microstructural properties...
AIM
The aim of the study is to systematically assess the impact of low-temperature degradation (LTD) simulation in an autoclave on mechanical and microstructural properties of infiltrated monolithic zirconia compared to the noninfiltrated zirconia.
SETTINGS AND DESIGN
Systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analysis 2020 guidelines.
MATERIALS AND METHODS
An electronic search was done within these databases: PubMed, Scopus, and Web of Science, Science Direct, Embase, Wiley, Google Scholar for articles published between 2000 and March 2021. Search results that met eligibility criteria were categorized into two groups based on properties assessed of infiltrated monolithic zirconia exposed to LTD (also called aging simulation) - (a) mechanical (flexural strength and fracture toughness) and (b) microstructural properties (phase transformation rate and m content).
STATISTICAL ANALYSIS USED
Qualitative analysis.
RESULTS
The search identified 272 preliminary results. After discarding duplicates, and screening of titles, abstracts, and full texts, 10 articles finally met inclusion criteria. Data were collected on author's details and their countries, journal and year of publication, type and percentage of infiltration, aging protocol (duration and temperature), mechanical, and microstructural properties. All the included studies invariably revealed better aging resistance without a change in mechanical properties for infiltrated monolithic zirconia as compared to noninfiltrated species.
CONCLUSION
Infiltration within monolithic zirconia can reduce degradation and simultaneously maintain their mechanical properties by preventing water entry into grain contours. The final m content was less for infiltrated Zirconium, indicating a lesser phase transformation and better aging resistance.
OTHER INFORMATION
Systematic review protocol registered at PROSPERO CRD42021248153.
Topics: Ceramics; Materials Testing; Zirconium; Flexural Strength
PubMed: 36511024
DOI: 10.4103/jips.jips_437_21 -
Dental Materials Journal Nov 2018The fluorescence and physical properties of thulium-doped zirconia were investigated. A standard grade of zirconia (TZ-3Y-E) and two translucent dental zirconia...
The fluorescence and physical properties of thulium-doped zirconia were investigated. A standard grade of zirconia (TZ-3Y-E) and two translucent dental zirconia materials (Zpex and Zpex Smile) were examined. The specimens were prepared by addition of 0-1.5 wt% TmO and then sintering. When exposed to UV light, the TmO-doped zirconia exhibited blue fluorescence with a peak wavelength of 460 nm. The fluorescence intensity of Zpex and Zpex Smile was higher than that of TZ-3Y-E, with Zpex being more intense than Zpex Smile. Zpex exhibited maximum fluorescence intensity when doped with 0.8 wt% TmO. XRD analysis revealed that TZ-3Y-E and Zpex contained primarily tetragonal zirconia, while Zpex Smile contained largely cubic phase zirconia. There were no changes observed in the microstructure or physical properties of the zirconia specimens when doped with TmO.
Topics: Dental Materials; Fluorescence; Hardness; Materials Testing; Microscopy, Electron, Scanning; Surface Properties; Thulium; Ultraviolet Rays; X-Ray Diffraction; Zirconium
PubMed: 30158350
DOI: 10.4012/dmj.2017-384 -
Inorganic Chemistry May 2022Metal-organic frameworks (MOFs) demonstrate strong potential for various important applications due to their well tunable structures and compositions through metal and...
Metal-organic frameworks (MOFs) demonstrate strong potential for various important applications due to their well tunable structures and compositions through metal and organic linker engineering. As an effective approach, topology evolution by controlling linker conformation has received considerable attention, where solvents and acids have crucial effects on structural formation. However, a systematic study of such effects remains under investigated. Herein, we carried out a methodical study on the topology evolution in Zr-MOFs directed by solvothermal conditions with various combinations of three common solvents and six different acids. As a result, three Zr-MOFs with different topologies, (HIAM-4007), (HIAM-4008), and (HIAM-4009), were obtained using the same Zr-cluster and tetratopic carboxylate linker, in which structure diversity shows significant influence on their corresponding photoluminescence quantum yields. Further experiments revealed that the acidity of acids and the basicity of solvents strongly influenced the linker conformation in the resultant MOFs, leading to the topology evolution. Such a solvent- and acid-assisted topology evolution represents a general approach that can be used with other tetratopic carboxylate linkers to realize structural diversity. The present work demonstrates an effective structure designing strategy by controlling synthetic conditions, which may prove to be powerful for customized synthesis of MOFs with specific structure and functionality.
Topics: Metal-Organic Frameworks; Solvents; Zirconium
PubMed: 35533367
DOI: 10.1021/acs.inorgchem.2c00660 -
Dental Materials Journal Jan 2023This review describes the development of ultra-high translucent zirconia (referred to as UHTZ) using new manufacturing technology and its characterization results. The... (Review)
Review
This review describes the development of ultra-high translucent zirconia (referred to as UHTZ) using new manufacturing technology and its characterization results. The development of UHTZ was primarily due to the adoption of two basic manufacturing technologies, "Cyclic CIP" and "Plus Y Technology". This manufacturing technology could provide stable processing characteristics, which improves chipping resistance during milling. Furthermore, the enlargement factor (processing coefficient) for UHTZ is smaller than those for conventional products. In general, the higher the light transmittance, the lower the flexural strength. Despite its extremely high translucency, the most significant feature of UTHZ is that its flexural strength is comparable to that of 5Y. Furthermore, UHTZ has higher chemical durability and uniform microstructure, which results in less wear on the opposing teeth and superior discoloration resistance. Therefore, UHTZ is a new option for inlay, onlay, and laminate veneer applications, where lithium disilicate glass ceramics has been widely used.
Topics: Materials Testing; Dental Porcelain; Ceramics; Zirconium; Flexural Strength; Surface Properties
PubMed: 36631076
DOI: 10.4012/dmj.2022-243 -
Medicina (Kaunas, Lithuania) Mar 2023Even with the demand for high esthetics, the strength of the material for esthetic applications continues to be important. In this study, monolith zirconia (MZi) crowns... (Randomized Controlled Trial)
Randomized Controlled Trial
Even with the demand for high esthetics, the strength of the material for esthetic applications continues to be important. In this study, monolith zirconia (MZi) crowns fabricated using CAD/CAM were tested for fracture resistance (FR) in teeth with class II cavity designs with varying proximal depths, restored through a deep marginal elevation technique (DME). : Forty premolars were randomly divided into four groups of ten teeth. In Group A, tooth preparation was conducted and MZi crowns were fabricated. In Group B, mesio-occluso-distal (MOD) cavities were prepared and restored with microhybrid composites before tooth preparation and the fabrication of MZi crowns. In Groups C and D, MOD cavities were prepared, differentiated by the depth of the gingival seat, 2 mm and 4 mm below the cemento-enamel junction (CEJ). Microhybrid composite resin was used for DME on the CEJ and for the restoration of the MOD cavities; beforehand, tooth preparations were conducted and MZi crowns were and cemented using resin cement. The maximum load to fracture (in newtons (N)) and FR (in megapascals (MPa)) were measured using the universal testing machine. The average scores indicate a gradual decrease in the load required to fracture the samples from Groups A to D, with mean values of 3415.61 N, 2494.11 N, 2108.25 N and 1891.95 N, respectively. ANOVA revealed highly significant differences between the groups. Multiple group comparisons using the Tukey HSD post hoc test revealed that Group D had greater DME depths and showed significant differences compared with Group B. FR in teeth decreased when more tooth structure was involved, even with MZi crowns. However, DME up to 2 mm below the CEJ did not negatively influence the FR. Strengthening the DME-treated teeth with MZi crowns could be a reasonable clinical option, as the force required to fracture the samples far exceeded the maximum recorded biting force for posterior teeth.
Topics: Humans; Bicuspid; Composite Resins; Crowns; Zirconium
PubMed: 37109619
DOI: 10.3390/medicina59040661 -
BMC Oral Health Apr 2022Wear resistance affects dental ceramics longevity and the functions of the opposing teeth. However, data for the effect of aqueous environment on wear resistance of...
BACKGROUND
Wear resistance affects dental ceramics longevity and the functions of the opposing teeth. However, data for the effect of aqueous environment on wear resistance of dental ceramics are lacking. This study evaluated the effect of aqueous environment on wear resistance of typical dental glass-ceramics.
METHODS
Disk specimens were prepared from lithium disilicate glass-ceramics (LD) and leucite reinforced glass-ceramics (LEU). The disk specimens paired with steatite antagonists were tested in a pin-on-disk tribometer under both wet and dry conditions with 10 N up to 500,000 wear cycles. The wear analysis of glass-ceramics was performed using a 3D profilometer after 100,000, 300,000 and 500,000 wear cycles. Wear morphologies were analyzed by employing scanning electron microscopy (SEM). The crystalline compositions of specimens stored in a dry environment and subsequently immersed in distilled water for 40 h were separately determined using X-ray diffraction (XRD). The chemical states of the wear surfaces for LD were analyzed by X-ray photoelectron spectroscopy (XPS). The data analysis and multiple pair-wise comparisons of means were performed by using one-way analysis of variance (ANOVA) and Tukey's post-hoc test.
RESULTS
LEU in a wet environment exhibited less wear volume loss than that in a dry environment (p < 0.05). The volume loss of LD in a wet environment was higher than that in a dry environment (p < 0.05). The wear volumes of steatite antagonists paired with two glass-ceramics under dry conditions were higher than under wet conditions.
CONCLUSIONS
XPS spectra of LD under wet conditions indicated that high wear loss might result from the effect of stress corrosion by water and reaction of water with the ionic-covalent bonds at the crack tip. XPS spectra and SEM images of LD under dry conditions showed a possible formation of tribofilm. Within the limitations of this in vitro study, water was wear-friendly to LEU and all opposing steatites but aggravated wear for LD.
Topics: Ceramics; Humans; Materials Testing; Surface Properties; Water; Zirconium
PubMed: 35473925
DOI: 10.1186/s12903-022-02183-5 -
Schweizer Monatsschrift Fur Zahnmedizin... 2013Zirconia is currently extensively used in medicine, especially in orthopedic surgery for various joint replacement appliances. Its outstanding mechanical and chemical... (Review)
Review
Zirconia is currently extensively used in medicine, especially in orthopedic surgery for various joint replacement appliances. Its outstanding mechanical and chemical properties have made it the "material of choice" for various types of prostheses. Its color in particular makes it a favored material to manufacture dental implants. A literature search through Medline enables one to see zirconia's potential but also to point out and identify its weaknesses. The search shows that zirconia is a biocompatible, osteoconductive material that has the ability to osseointegrate. Its strength of bonding to bone depends on the surface structure of the implant. Although interesting, the studies do not allow for the recommendation of the use of zirconia implants in daily practice. The lack of studies examining the chemical and structural composition of zirconia implants does not allow for a "gold standard" to be established in the implant manufacturing process. Randomized clinical trials (RCT) are urgently needed on surface treatments of zirconia implants intended to achieve the best possible osseointegration.
Topics: Animals; Biocompatible Materials; Biotransformation; Color; Dental Implants; Dental Materials; Dental Porcelain; Dental Prosthesis Design; Dental Stress Analysis; Hardness; Humans; Mechanical Phenomena; Osseointegration; Zirconium
PubMed: 23965893
DOI: No ID Found