17 results on '"Prymak, O."'
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2. Thermal Behavior of Silver–Gold Core–Shell Nanocubes: In Situ X-ray Diffraction and In Situ Electron Microscopy (SEM and TEM)
- Author
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Karatzia, A., primary, Loza, K., additional, Prymak, O., additional, Heggen, M., additional, and Epple, M., additional
- Published
- 2023
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3. In-depth characterization of ultrasmall nanoparticles by combined X-ray techniques
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Prymak, O., primary, Wetzel, O., additional, Wolff, N., additional, Loza, K., additional, Heggen, M., additional, Weidenthaler, C., additional, Oliveira, C. L. P., additional, and Epple, M., additional
- Published
- 2023
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4. Favorable features of a calcium phosphate cement based on a metastable α ̅-tricalcium phosphate and reinforced by hydroxyapatite whiskers.
- Author
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Zyman, Z, Epple, M, Goncharenko, A, Onyshchenko, O, Rokhmistrov, D, Prymak, O, and Loza, K
- Published
- 2023
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5. Merging of a Supramolecular Ligand with a Switchable Luminophore - Light-Responsiveness, Photophysics and Bioimaging.
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Balszuweit J, Stahl P, Cappellari V, Lorberg RY, Wölper C, Niemeyer FC, Koch J, Prymak O, Knauer SK, Strassert CA, and Voskuhl J
- Subjects
- Ligands, Humans, Light, Crystallography, X-Ray, Stilbenes chemistry, Luminescence, Pyrroles chemistry
- Abstract
In this contribution we report on a novel approach towards luminescent light-responsive ligands. To this end, cyanostilbene- guanidiniocarbonyl-pyrrole hybrids were designed and investigated. Merging of a luminophore with a supramolecular bioactive ligand bears numerous advantages by overcoming the typical drawbacks of drug-labelling, influencing the overall performance of the active species by attachment of a large luminophore. Here we were able to establish a simple and easily accessible synthesis route to different cyanostyryl-guanidininiocarbonyl-pyrrole (CGCP) derivatives. These compounds were investigated regarding their light-responsive double bond isomerisation, their molecular structures in single crystals by means of X-ray diffractometry, their emission properties by state of the art photophysical characterisation as well as bioimaging and assessment of cell toxicity., (© 2024 The Author(s). Chemistry - A European Journal published by Wiley-VCH GmbH.)
- Published
- 2024
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6. Conversion of Ultrasmall Glutathione-Coated Silver Nanoparticles during Dispersion in Water into Ultrasmall Silver Sulfide Nanoparticles.
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Wolff N, Prymak O, Białas N, Schaller T, Loza K, Niemeyer F, Heggen M, Weidenthaler C, Oliveira CLP, and Epple M
- Abstract
Ultrasmall silver nanoparticles (2 nm) were prepared by reduction with sodium borohydride (NaBH
4 ) and stabilized by the ligand glutathione (a tripeptide: glycine-cysteine-glutamic acid). NMR spectroscopy and optical spectroscopy (UV and fluorescence) revealed that these particles initially consist of silver nanoparticles and fluorescing silver nanoclusters, both stabilized by glutathione. Over time, the silver nanoclusters disappear and only the silver nanoparticles remain. Furthermore, the capping ligand glutathione eliminates hydrogen sulfide (H2 S) from the central cysteine and is released from the nanoparticle surface as tripeptide glycine-dehydroalanine-glutamic acid. Hydrogen sulfide reacts with the silver core to form silver sulfide. After four weeks in dispersion at 4 °C, this process is completed. These processes cannot be detected by transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), or differential centrifugal sedimentation (DCS) as these methods cannot resolve the mixture of nanoparticles and nanoclusters or the nature of the nanoparticle core. X-ray photoelectron spectroscopy showed the mostly oxidized state of the silver nanoparticle core, Ag(+I), both in freshly prepared and in aged silver nanoparticles. These results demonstrate that ultrasmall nanoparticles can undergo unnoticed changes that considerably affect their chemical, physical, and biological properties. In particular, freshly prepared ultrasmall silver nanoparticles are much more toxic against cells and bacteria than aged particles because of the presence of the silver clusters.- Published
- 2024
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7. Intrinsically Conductive and Cu-Functionalized Polymer-Composite Membranes as Gas Diffusion Electrodes for CO2 Electroreduction.
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Sanjuán I, Kumbhar V, Prymak O, Ulbricht M, Andronescu C, and Fischer L
- Abstract
We introduced a new class of gas diffusion electrodes (GDEs) with adjustable pore morphology. We fabricated intrinsically conductive polymer-composite membranes containing carbon filler, enabling a pore structure variation through film casting cum phase separation protocols. We further selectively functionalized specific pore regions of the membranes with Cu by a NaBH4-facilitated coating strategy. The as-obtained GDEs can facilitate the electrochemical CO2 reduction reaction (CO2RR) at Cu active sites that are presented inside a defined and electrically conductive pore system. When employing them as free-standing cathodes in a CO2 flow electrolyzer, we achieved >70% Faradaic efficiencies for CO2RR products at up to 200 mA/cm2. We further demonstrated that deposition of a dense Cu layer on top of the membrane leads to obstruction of the underlying pore openings, inhibiting an excessive wetting of the pore pathways that transport gaseous CO2. However, the presentation of Cu inside the pore system of our novel membrane electrodes increased the C2H4/CO selectivity by a factor of up to 3 compared to Cu presented in the dense layer on top of the membrane. Additionally, we found that gaseous CO2 could still access Cu in macropores after wetting with electrolyte, while CO2RR was completely suppressed in wetted nm-scale pores., (© 2024 Wiley‐VCH GmbH.)
- Published
- 2024
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8. Increased Cytotoxicity of Bimetallic Ultrasmall Silver-Platinum Nanoparticles (2 nm) on Cells and Bacteria in Comparison to Silver Nanoparticles of the Same Size.
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Wolff N, Białas N, Loza K, Heggen M, Schaller T, Niemeyer F, Weidenthaler C, Beuck C, Bayer P, Prymak O, Oliveira CLP, and Epple M
- Abstract
Ultrasmall nanoparticles (diameter 2 nm) of silver, platinum, and bimetallic nanoparticles (molar ratio of Ag:Pt 0:100; 20:80; 50:50; 70:30; 100:0), stabilized by the thiolated ligand glutathione, were prepared and characterized by transmission electron microscopy, differential centrifugal sedimentation, X-ray photoelectron spectroscopy, small-angle X-ray scattering, X-ray powder diffraction, and NMR spectroscopy in aqueous dispersion. Gold nanoparticles of the same size were prepared as control. The particles were fluorescently labeled by conjugation of the dye AlexaFluor-647 via copper-catalyzed azide-alkyne cycloaddition after converting amine groups of glutathione into azide groups. All nanoparticles were well taken up by HeLa cells. The cytotoxicity was assessed with an MTT test on HeLa cells and minimal inhibitory concentration (MIC) tests on the bacteria Escherichia coli and Staphylococcus xylosus . Notably, bimetallic AgPt nanoparticles had a higher cytotoxicity against cells and bacteria than monometallic silver nanoparticles or a physical mixture of silver and platinum nanoparticles. However, the measured release of silver ions from monometallic and bimetallic silver nanoparticles in water was very low despite the ultrasmall size and the associated high specific surface area. This is probably due to the surface protection by a dense layer of thiolated ligand glutathione. Thus, the enhanced cytotoxicity of bimetallic AgPt nanoparticles is caused by the biological environment in cell culture media, together with a polarization of silver by platinum.
- Published
- 2024
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9. The Application of Ultrasmall Gold Nanoparticles (2 nm) Functionalized with Doxorubicin in Three-Dimensional Normal and Glioblastoma Organoid Models of the Blood-Brain Barrier.
- Author
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Kostka K, Sokolova V, El-Taibany A, Kruse B, Porada D, Wolff N, Prymak O, Seeds MC, Epple M, and Atala AJ
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- Humans, Brain Neoplasms drug therapy, Brain Neoplasms metabolism, Brain Neoplasms pathology, Cell Line, Tumor, Doxorubicin pharmacology, Doxorubicin chemistry, Doxorubicin pharmacokinetics, Glioblastoma drug therapy, Glioblastoma metabolism, Glioblastoma pathology, Metal Nanoparticles chemistry, Gold chemistry, Blood-Brain Barrier metabolism, Blood-Brain Barrier drug effects, Organoids drug effects, Organoids metabolism
- Abstract
Among brain tumors, glioblastoma (GBM) is very challenging to treat as chemotherapeutic drugs can only penetrate the brain to a limited extent due to the blood-brain barrier (BBB). Nanoparticles can be an attractive solution for the treatment of GBM as they can transport drugs across the BBB into the tumor. In this study, normal and GBM organoids comprising six brain cell types were developed and applied to study the uptake, BBB penetration, distribution, and efficacy of fluorescent, ultrasmall gold nanoparticles (AuTio-Dox-AF647s) conjugated with doxorubicin (Dox) and AlexaFluor-647-cadaverine (AF647) by confocal laser scanning microscopy (CLSM), using a mixture of dissolved doxorubicin and fluorescent AF647 molecules as a control. It was shown that the nanoparticles could easily penetrate the BBB and were found in normal and GBM organoids, while the dissolved Dox and AF647 molecules alone were unable to penetrate the BBB. Flow cytometry showed a reduction in glioblastoma cells after treatment with AuTio-Dox nanoparticles, as well as a higher uptake of these nanoparticles by GBM cells in the GBM model compared to astrocytes in the normal cell organoids. In summary, our results show that ultrasmall gold nanoparticles can serve as suitable carriers for the delivery of drugs into organoids to study BBB function.
- Published
- 2024
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10. The Molecular Footprint of Peptides on the Surface of Ultrasmall Gold Nanoparticles (2 nm) Is Governed by Steric Demand.
- Author
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Wagner LS, Prymak O, Schaller T, Beuck C, Loza K, Niemeyer F, Gumbiowski N, Kostka K, Bayer P, Heggen M, Oliveira CLP, and Epple M
- Subjects
- Surface Properties, Particle Size, Gold chemistry, Metal Nanoparticles chemistry, Peptides chemistry
- Abstract
Ultrasmall gold nanoparticles were functionalized with peptides of two to seven amino acids that contained one cysteine molecule as anchor via a thiol-gold bond and a number of alanine residues as nonbinding amino acid. The cysteine was located either in the center of the molecule or at the end (C-terminus). For comparison, gold nanoparticles were also functionalized with cysteine alone. The particles were characterized by UV spectroscopy, differential centrifugal sedimentation (DCS), high-resolution transmission electron microscopy (HRTEM), and small-angle X-ray scattering (SAXS). This confirmed the uniform metal core (2 nm diameter). The hydrodynamic diameter was probed by
1 H-DOSY NMR spectroscopy and showed an increase in thickness of the hydrated peptide layer with increasing peptide size (up to 1.4 nm for heptapeptides; 0.20 nm per amino acid in the peptide).1 H NMR spectroscopy of water-dispersed nanoparticles showed the integrity of the peptides and the effect of the metal core on the peptide. Notably, the NMR signals were very broad near the metal surface and became increasingly narrow in a distance. In particular, the methyl groups of alanine can be used as probe for the resolution of the NMR spectra. The number of peptide ligands on each nanoparticle was determined using quantitative1 H NMR spectroscopy. It decreased with increasing peptide length from about 100 for a dipeptide to about 12 for a heptapeptide, resulting in an increase of the molecular footprint from about 0.1 to 1.1 nm2 .- Published
- 2024
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11. Integrated In Situ Fabrication of CuO Nanorod-Decorated Polymer Membranes for the Catalytic Flow-Through Reduction of p -Nitrophenol.
- Author
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Hesaraki SAH, Prymak O, Heidelmann M, Ulbricht M, and Fischer L
- Abstract
We developed a novel method to fabricate copper nanorods in situ in a poly(ether sulfone) (15 wt %) casting solution by a sonochemical reduction of Cu
2+ ions with NaBH4 . The main twist is the addition of ethanol to remove excess NaBH4 through Cu(0) catalyzed ethanolysis. This enabled the direct use of the resulting copper-containing casting dispersions for membrane preparation by liquid nonsolvent-induced phase separation and led to full utilization of the copper source, generating zero metal waste. We characterized the copper nanorods as presented in the membranes via scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and UV/vis spectroscopy. We could demonstrate that the rapid immobilization from reducing conditions led to the membrane incorporation of copper nanorods in a state of high reactivity, which also promoted the complete oxidation to CuO after fabrication. We further observed a large aspect ratio and crystal straining of the nanorods, likely resulting from growth around the matrix polymer. The entanglement with poly(ether sulfone) further facilitated a selective presentation at the pore surface of the final CuO-decorated membranes. The membranes also exhibit high water permeances of up to 2800 L/m2 hbar. Our catalytic membranes achieved exceptionally high activities in the aqueous flow-through reduction of p -nitrophenol ( p -NP), with turnover frequencies of up to 115 h-1 , even surpassing those of other state-of-the-art catalytic membranes that incorporate Pd or Ag. Additionally, we demonstrated that catalytic hydrolysis of the reducing agent in water can lead to hydrogen gas formation and blocking of active sites during continuous catalytic p -NP hydrogenation. We illustrated that the accompanying conversion loss can be mitigated by facilitated gas transport in the water-filled pores, which is dependent on the orientation of the pore size gradient and the flow direction.- Published
- 2024
- Full Text
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12. Development of triple-functionalized calcium phosphate nanoparticles as an advanced drug delivery system for bone tissue repair.
- Author
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Tenkumo T, Kruse B, Kostka K, Sokolova V, Ogawa T, Yoda N, Prymak O, Suzuki O, Sasaki K, and Epple M
- Abstract
Introduction: During tissue repair or regeneration, several bioactive molecules are released and interact with each other and act as complex additives or inhibitors for tissue reconstruction. In this study, the bone-healing effects of the combination treatment with tumor necrosis factor-α (TNF-α) inhibition, vascular endothelial growth factor A (VEGF-A) and bone morphogenetic protein-7 (BMP-7) release by gene silencing, and gene transfection with calcium phosphate nanoparticles (CaP) in the rat femoral head was histologically, morphologically, and biochemically evaluated., Methods: A triple-functionalized paste of CaP carrying plasmid DNA encoding for BMP-7 and for VEGF), and siRNA against TNF-α was developed and denoted as CaP3mix. To compare the effects of 3mixCaP, CaP with plasmid DNA encoding BMP-7, VEGF, or siRNA encoding TNF-α was prepared and denoted as CaP/PEI/pBMP-7/SiO
2 , CaP/PEI/pVEGF/SiO2 , or CaP/PEI/siRNA-TNF-α/SiO2 , respectively. The bone healing in bone defects in the rat femoral head was investigated after 10 and 21 days of implantation., Results: The levels of bone formation-related markers OCN, Runx2, and SP7 increased at the protein and gene levels in 3mixCaP after 10 days, and 3mixCaP significantly accelerated bone healing compared with the other treatments after 21 days of implantation., Conclusion: The triple-functionalized CaP paste loading plasmid DNA encoding BMP-7 and VEGF and siRNA encoding TNF-α is a promising bioactive material for bone tissue repair., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Japanese Society for Regenerative Medicine. Production and hosting by Elsevier B.V.)- Published
- 2023
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13. Ultrastructure and Surface Composition of Glutathione-Terminated Ultrasmall Silver, Gold, Platinum, and Alloyed Silver-Platinum Nanoparticles (2 nm).
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Wolff N, Loza K, Heggen M, Schaller T, Niemeyer F, Bayer P, Beuck C, Oliveira CLP, Prymak O, Weidenthaler C, and Epple M
- Abstract
Alloyed ultrasmall silver-platinum nanoparticles (molar ratio Ag:Pt = 50:50) were prepared and compared to pure silver, platinum, and gold nanoparticles, all with a metallic core diameter of 2 nm. They were surface-stabilized by a layer of glutathione (GSH). A comprehensive characterization by high-resolution transmission electron microscopy (HRTEM), electron diffraction (ED), X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), differential centrifugal sedimentation (DCS), and UV spectroscopy showed their size both in the dry and in the water-dispersed state (hydrodynamic diameter). Solution NMR spectroscopy (
1 H,13 C, COSY, HSQC, HMBC, and DOSY) showed the nature of the glutathione shell including the number of GSH ligands on each nanoparticle (about 200 with a molecular footprint of 0.063 nm2 each). It furthermore showed that there are at least two different positions for the GSH ligand on the gold nanoparticle surface. Platinum strongly reduced the resolution of the NMR spectra compared to silver and gold, also in the alloyed nanoparticles. X-ray photoelectron spectroscopy (XPS) showed that silver, platinum, and silver-platinum particles were at least partially oxidized to Ag(+I) and Pt(+II), whereas the gold nanoparticles showed no sign of oxidation. Platinum and gold nanoparticles were well crystalline but twinned (fcc lattice) despite the small particle size. Silver was crystalline in electron diffraction but not in X-ray diffraction. Alloyed silver-platinum nanoparticles were almost fully amorphous by both methods, indicating a considerable internal disorder.- Published
- 2023
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14. Cell-Biological Response and Sub-Toxic Inflammatory Effects of Titanium Dioxide Particles with Defined Polymorphic Phase, Size, and Shape.
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Breisch M, Olejnik M, Loza K, Prymak O, Rosenkranz N, Bünger J, Sengstock C, Köller M, Westphal G, and Epple M
- Abstract
Six types of titanium dioxide particles with defined size, shape, and crystal structure (polymorphic form) were prepared: nanorods (70 × 25 nm
2 ), rutile sub-microrods (190 × 40 nm2 ), rutile microspheres (620 nm), anatase nanospheres (100 nm), anatase microspheres (510 nm), and amorphous titania microspheres (620 nm). All particles were characterized by scanning electron microscopy, X-ray powder diffraction, dynamic light scattering, infrared spectroscopy, and UV spectroscopy. The sub-toxic cell-biological response to these particles by NR8383 macrophages was assessed. All particle types were taken up well by the cells. The cytotoxicity and the induction of reactive oxygen species (ROS) were negligible for all particles up to a dose of 100 µg mL-1 , except for rutile microspheres which had a very rough surface in contrast to anatase and amorphous titania microspheres. The particle-induced cell migration assay (PICMA; based on chemotaxis) of all titanium dioxide particles was comparable to the effect of control silica nanoparticles (50 nm, uncoated, agglomerated) but did not show a trend with respect to particle size, shape, or crystal structure. The coating with carboxymethylcellulose (CMC) had no significant biological effect. However, the rough surface of rutile microspheres clearly induced pro-inflammatory cell reactions that were not predictable by the primary particle size alone.- Published
- 2023
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15. Tuning the Fluorescence in Dynamic Covalent Bonded Liquid Crystals.
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Blanke M, Neumann T, Gutierrez Suburu ME, Prymak O, Wölper C, Strassert CA, and Giese M
- Abstract
A series of emissive liquid crystalline materials based on salicylidene derivatives is reported and investigated with respect to their thermoresponsive and mechanochromic properties. Single-crystal analysis and temperature-dependent powder X-ray diffraction measurements allowed us to correlate the intermolecular organization of the mesogens with thermoresponsive changes in the fluorescence behavior. As a proof-of-principle study, we employed the dynamics of the imine bond in transamination reactions for postsynthetic tuning of the fluorescence behavior as a further step toward the development of adaptive materials.
- Published
- 2022
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16. Water-Based Synthesis of Ultrasmall Nanoparticles of Platinum Group Metal Oxides (1.8 nm).
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Wetzel O, Prymak O, Loza K, Gumbiowski N, Heggen M, Bayer P, Beuck C, Weidenthaler C, and Epple M
- Subjects
- Platinum chemistry, Water chemistry, X-Ray Diffraction, Metal Nanoparticles chemistry, Oxides chemistry
- Abstract
Ultrasmall nanoparticles of platinum group metal oxides (core diameter of about 1.8 nm) were prepared by alkaline hydrolysis of metal precursors in the presence of NaBH
4 and by colloidal stabilization with tripeptide glutathione. We obtained water-dispersed nanoparticles of Rh2 O3 , PdO, RuO2 , IrO2 , Os/OsO2 , and Pt/PtO. Their size was probed using high-resolution transmission electron microscopy, differential centrifugal sedimentation, small-angle X-ray scattering, and diffusion-ordered1 H NMR spectroscopy (1 H DOSY). Their oxidation state was clearly determined using X-ray photoelectron spectroscopy, X-ray powder diffraction, and electron diffraction. The chemical composition of the nanoparticles, that is, the ratio of the metal oxide core and glutathione capping agent, was quantitatively determined by a combination of these methods.- Published
- 2022
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17. Colloidal stability, cytotoxicity, and cellular uptake of HfO 2 nanoparticles.
- Author
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McGinnity TL, Sokolova V, Prymak O, Nallathamby PD, Epple M, and Roeder RK
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- Cell Membrane Permeability, Cell Survival drug effects, Fluorescent Dyes chemistry, HeLa Cells, Humans, Microscopy, Electron, Transmission, Optical Imaging, THP-1 Cells, Hafnium chemistry, Metal Nanoparticles chemistry, Oxides chemistry
- Abstract
The colloidal stability, cytotoxicity, and cellular uptake of hafnium oxide (HfO
2 ) nanoparticles (NPs) were investigated in vitro to assess safety and efficacy for use as a deliverable theranostic in nanomedicine. Monoclinic HfO2 NPs, ~60-90 nm in diameter and ellipsoidal in shape, were directly prepared without calcination by a hydrothermal synthesis at 83% yield. The as-prepared, bare HfO2 NPs exhibited colloidal stability in cell culture media for at least 10 days without significant agglomeration or settling. The viability (live/dead assay) of human epithelial cells (HeLa) and monocyte-derived macrophages (THP-1) did not fall below 95% of untreated cells after up to 24 h exposure to HfO2 NPs at concentrations up to 0.80 mg/ml. Similarly, the mitochondrial activity (MTT assay) of HeLa and THP-1 cells did not fall below 80% of untreated cells after up to 24 h exposure to HfO2 NPs at concentrations up to 0.40 mg/ml. Cellular uptake was confirmed and visualized in both HeLa and THP-1 cells by fluorescence microscopy of HfO2 NPs labeled with Cy5 and transmission electron microscopy (TEM) of bare HfO2 NPs. TEM micrographs provided direct observation of macropinocytosis and endosomal compartmentalization within 4 h of exposure. Thus, the HfO2 NPs in this study exhibited colloidal stability, cytocompatibility, and cellular uptake for potential use as a deliverable theranostic in nanomedicine., (© 2021 Wiley Periodicals LLC.)- Published
- 2021
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