Several technetium-99 BATO (boronic acid adduct of technetium dioximes) complexes TcX(dioxime)3BR (X = Cl) that contain a boron cap R which bears a 2- or 4-nitroimidazole moiety have been prepared from either TcCl(dioxime)3 or from Tc(dioxime)3(mu-OH)SnCl3 [dioxime = dimethyl glyoxime (DMG) or cyclohexanedione dioxime (CDO)]. Two hydroxy analogs (X = OH) were isolated by treatment of the corresponding chloro complexes with aqueous NaOH. The complexes have been characterized by elemental analysis, mass spectrometry, NMR, UV/vis spectroscopy, and high-performance liquid chromatography. These complexes have the potential for selective retention in hypoxic tissue, by a mechanism believed to be the result of nitro reduction. The electrochemistry and enzymatic reduction of these complexes was studied to assess the potential for reduction in vivo. The nitroreductase enzyme xanthine oxidase was shown to reduce the nitroimidazole group on the complexes 99TcOH(DMG)3BBNO2 and 99TcOH(DMG)3BprenNO2 under anaerobic conditions in the presence of hypoxanthine. However, the results indicated that the rate of reduction might be slow in vivo, limiting the suitability of these compounds for imaging of regions of hypoxia.
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http://dx.doi.org/10.1021/bc00023a004 | DOI Listing |
J Biomed Mater Res B Appl Biomater
February 2025
Bioassays and Cellular Dynamics Lab, Department of Chemical and Biological Sciences, Institute of Biosciences, UNESP: São Paulo State University, São Paulo, Brazil.
Calcium phosphates, notably monetite, are valued biomaterials for bone applications owing to their osteogenic properties and rapid uptake by bone cells. This study investigates the enhancement of these properties through Cobalt doping, which is known to induce hypoxia and promote bone cell differentiation. Heat treatments at 700°C, 900°C, and 1050°C are applied to both monetite and Cobalt-doped monetite, facilitating the development of purer, more crystalline phases with varied particle sizes and optimized cellular responses.
View Article and Find Full Text PDFNephrology (Carlton)
February 2025
Department of Quality Management, Tianjin Blood Center, Tianjin, China.
Aim: To study the effect and elucidate the underlying mechanisms of VDAC1-ΔC on autophagy in renal tubular epithelial cells injured by hypoxia/reoxygenation.
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Neuromolecular Med
January 2025
Biochemistry and Molecular Biology Laboratory, Department of Zoology, Institute of Science, Banaras Hindu University, Varanasi, 221 005, India.
Hypoxia is a significant stressor, and stabilized hypoxia-inducible factor-1α (HIF-1α) regulates the expression of numerous genes, leading to various biochemical, molecular, physiological and genomic changes. The body's oxygen-sensing system activates gene expression to protect brain tissues from hypoxia. Gamma-aminobutyric acid, an inhibitory neurotransmitter, regulates brain excitability during hypoxia through the activation of HIF-1 α.
View Article and Find Full Text PDFGels
January 2025
Microenvironmental Engineering Laboratory, Department of Bioengineering, Clemson University, Clemson, SC 29634, USA.
Hypoxia-inducible factor-1α (HIF-1α) initiates the cellular response to low oxygen levels, making it an attractive target for stimulating therapeutic angiogenesis. Several small molecules have been identified that stabilize HIF-1α and activate the angiogenic signaling pathway. However, achieving therapeutic doses of bioactive small molecules in target tissues remains challenging.
View Article and Find Full Text PDFBioengineering (Basel)
January 2025
Section of Cardiac Surgery, Department of Surgery, University of Chicago, 5841 S. Maryland Ave., Chicago, IL 60637, USA.
Spheroids serve as the building blocks for three-dimensional (3D) bioprinted tissue patches. When larger than 500 μm, the desired size for 3D bioprinting, they tend to have a hypoxic core with necrotic cells. Therefore, it is critical to assess the viability of spheroids in order to ensure the successful fabrication of high-viability patches.
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