Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 875
Filtrar
Mais filtros

País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Small ; 20(25): e2310180, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38342676

RESUMO

Knee replacement surgery confronts challenges including patient dissatisfaction and the necessity for secondary procedures. A key requirement lies in dual-modal measurement of force and temperature of artificial joints during postoperative monitoring. Here, a novel non-toxic near-infrared (NIR) phosphor Sr3Sn2O7:Nd, Yb, is designed to realize the dual-modal measurement. The strategy is to entail phonon-assisted upconversion luminescence (UCL) and trap-controlled mechanoluminescence (ML) in a single phosphor well within the NIR biological transmission window. The phosphor is embedded in medical bone cement forming a smart joint in total knee replacements illustrated as a proof-of-concept. The sensing device can be charged in vitro by a commercial X-ray source with a safe dose rate for ML, and excited by a low power 980 nm laser for UCL. It attains impressive force and temperature sensing capabilities, exhibiting a force resolution of 0.5% per 10 N, force detection threshold of 15 N, and a relative temperature sensitive of up to 1.3% K-1 at 309 K. The stability against humidity and thermal shock together with the robustness of the device are attested. This work introduces a novel methodological paradigm, paving the way for innovative research to enhance the functionality of artificial tissues and joints in living organisms.


Assuntos
Artroplastia do Joelho , Temperatura , Humanos , Estrôncio/química , Itérbio/química , Luminescência , Neodímio/química , Medições Luminescentes/métodos , Raios Infravermelhos
2.
Opt Lett ; 49(13): 3612-3615, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38950222

RESUMO

While lasers have found their successful applications in various clinical specialties, in clinical dental practice, traditional mechanical drills are still predominantly utilized. Although erbium-doped lasers have been demonstrated for dental therapy, their clinical performance is still not satisfactory due to the long pulse width, low peak power, and small repetition rate. To attain a smaller thermal diffusion thus better biological safety and surgical precision, as well as more rapid ablation, the advancement of femtosecond laser techniques has opened another route of dental surgery; however, no biological safety investigation has been reported. Here, we present a systematic study of dental ablation by a Yb:CaAlGdO4 regenerative amplifier with a central wavelength of 1040 nm and pulse width of 160 fs. The in vivo experiment of dental surgery investigating the inflammatory response has been reported, for the first time to the best of our knowledge. It is demonstrated that dental surgery by Yb:CaAlGdO4 femtosecond laser ablation has better biological safety compared to the turbine drilling, thanks to its non-contact and ultrafast heat dissipation nature.


Assuntos
Terapia a Laser , Terapia a Laser/métodos , Terapia a Laser/instrumentação , Animais , Itérbio/química , Lasers de Estado Sólido
3.
Eur J Nucl Med Mol Imaging ; 51(6): 1558-1573, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38270686

RESUMO

PURPOSE: Classical brachytherapy of solid malignant tumors is an invasive procedure which often results in an uneven dose distribution, while requiring surgical removal of sealed radioactive seed sources after a certain period of time. To circumvent these issues, we report the synthesis of intrinsically radiolabeled and gum Arabic glycoprotein functionalized [169Yb]Yb2O3 nanoseeds as a novel nanoscale brachytherapy agent, which could directly be administered via intratumoral injection for tumor therapy. METHODS: 169Yb (T½ = 32 days) was produced by neutron irradiation of enriched (15.2% in 168Yb) Yb2O3 target in a nuclear reactor, radiochemically converted to [169Yb]YbCl3 and used for nanoparticle (NP) synthesis. Intrinsically radiolabeled NP were synthesized by controlled hydrolysis of Yb3+ ions in gum Arabic glycoprotein medium. In vivo SPECT/CT imaging, autoradiography, and biodistribution studies were performed after intratumoral injection of radiolabeled NP in B16F10 tumor bearing C57BL/6 mice. Systematic tumor regression studies and histopathological analyses were performed to demonstrate therapeutic efficacy in the same mice model. RESULTS: The nanoformulation was a clear solution having high colloidal and radiochemical stability. Uniform distribution and retention of the radiolabeled nanoformulation in the tumor mass were observed via SPECT/CT imaging and autoradiography studies. In a tumor regression study, tumor growth was significantly arrested with different doses of radiolabeled NP compared to the control and the best treatment effect was observed with ~ 27.8 MBq dose. In histopathological analysis, loss of mitotic cells was apparent in tumor tissue of treated groups, whereas no significant damage in kidney, lungs, and liver tissue morphology was observed. CONCLUSIONS: These results hold promise for nanoscale brachytherapy to become a clinically practical treatment modality for unresectable solid cancers.


Assuntos
Braquiterapia , Itérbio , Animais , Braquiterapia/métodos , Camundongos , Itérbio/química , Distribuição Tecidual , Nanopartículas/química , Marcação por Isótopo , Tomografia Computadorizada com Tomografia Computadorizada de Emissão de Fóton Único , Camundongos Endogâmicos C57BL , Goma Arábica/química , Feminino , Glicoproteínas/química , Linhagem Celular Tumoral , Radioisótopos/química , Radioisótopos/uso terapêutico
4.
Int J Mol Sci ; 25(14)2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39063119

RESUMO

Thin films of the superconductor YBa2Cu3O7-δ (YBCO) were modified by low-energy light-ion irradiation employing collimated or focused He+ beams, and the long-term stability of irradiation-induced defects was investigated. For films irradiated with collimated beams, the resistance was measured in situ during and after irradiation and analyzed using a phenomenological model. The formation and stability of irradiation-induced defects are highly influenced by temperature. Thermal annealing experiments conducted in an Ar atmosphere at various temperatures demonstrated a decrease in resistivity and allowed us to determine diffusion coefficients and the activation energy ΔE=(0.31±0.03) eV for diffusive oxygen rearrangement within the YBCO unit cell basal plane. Additionally, thin YBCO films, nanostructured by focused He+-beam irradiation into vortex pinning arrays, displayed significant commensurability effects in magnetic fields. Despite the strong modulation of defect densities in these pinning arrays, oxygen diffusion during room-temperature annealing over almost six years did not compromise the signatures of vortex matching, which remained precisely at their magnetic fields predicted by the pattern geometry. Moreover, the critical current increased substantially within the entire magnetic field range after long-term storage in dry air. These findings underscore the potential of ion irradiation in tailoring the superconducting properties of thin YBCO films.


Assuntos
Cobre , Cobre/química , Temperatura , Supercondutividade , Itérbio/química , Oxigênio/química , Condutividade Elétrica
5.
Small ; 18(29): e2107976, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35732601

RESUMO

The spatial distribution and concentration of lanthanide activator and sensitizer dopant ions are of key importance for the luminescence color and efficiency of upconverting nanoparticles (UCNPs). Quantifying dopant ion distributions and intermixing, and correlating them with synthesis methods require suitable analytical techniques. Here, X-ray photoelectron spectroscopy depth-profiling with tender X-rays (2000-6000 eV), providing probe depths ideally matched to UCNP sizes, is used to measure the depth-dependent concentration ratios of Er3+ to Yb3+ , [Er3+ ]/[Yb3+ ], in three types of UCNPs prepared using different reagents and synthesis methods. This is combined with data simulations and inductively coupled plasma-optical emission spectroscopy (ICP-OES) measurements of the lanthanide ion concentrations to construct models of the UCNPs' dopant ion distributions. The UCNP sizes and architectures are chosen to demonstrate the potential of this approach. Core-only UCNPs synthesized with XCl3 ·6H2 O precursors (ß-phase) exhibit a homogeneous distribution of lanthanide ions, but a slightly surface-enhanced [Er3+ ]/[Yb3+ ] is observed for UCNPs prepared with trifluroacetate precursors (α-phase). Examination of Yb-core@Er-shell UCNPs reveals a co-doped, intermixed region between the single-doped core and shell. The impact of these different dopant ion distributions on the UCNP's optical properties is discussed to highlight their importance for UCNP functionality and the design of efficient UCNPs.


Assuntos
Érbio , Fluoretos , Nanopartículas , Itérbio , Ítrio , Cátions , Érbio/química , Fluoretos/química , Luminescência , Nanopartículas/química , Espectroscopia Fotoeletrônica , Raios X , Itérbio/química , Ítrio/química
6.
Biotechnol Appl Biochem ; 69(3): 920-929, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33830536

RESUMO

Ex vivo interaction of NaYF4 :Yb,Er nanophosphors with isolated mitochondria has been investigated. The nanophosphors were synthesized using the hydrothermal method. The synthesized NaYF4 :Yb,Er nanophosphors were characterized for physicochemical properties. The NaYF4 :Yb,Er nanophosphors showed successful upconversion with excitation wavelength lying in the near-infrared region. The effect of synthesized NaYF4 :Yb,Er nanophosphors on mitochondria isolated from the chicken heart tissue was examined through ROS generation capacity, membrane fluidity, and complex II activity. The exposer of NaYF4 :Yb,Er nanophosphors to isolated mitochondria inhibits ROS generation activity as compared to control. The mitochondria membrane fluidity of the lipid bilayer and complex-II activity of mitochondria was observed to be unaltered after the interaction with NaYF4 :Yb,Er nanoparticles. The results confirm that synthesized NaYF4 :Yb,Er nanoparticles can be used as a safe contrast agent.


Assuntos
Érbio , Itérbio , Érbio/química , Fluoretos/química , Fluoretos/farmacologia , Mitocôndrias , Espécies Reativas de Oxigênio , Itérbio/química , Ítrio/química
7.
Proc Natl Acad Sci U S A ; 116(15): 7232-7237, 2019 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-30898884

RESUMO

Ferroquadrupole order associated with local [Formula: see text] atomic orbitals of rare-earth ions is a realization of electronic nematic order. However, there are relatively few examples of intermetallic materials which exhibit continuous ferroquadrupole phase transitions, motivating the search for additional materials that fall into this category. Furthermore, it is not clear a priori whether experimental approaches based on transport measurements which have been successfully used to probe the nematic susceptibility in materials such as the Fe-based superconductors will be as effective in the case of [Formula: see text] intermetallic materials, for which the important electronic degrees of freedom are local rather than itinerant and are consequently less strongly coupled to the charge-carrying quasiparticles near the Fermi energy. In the present work, we demonstrate that the intermetallic compound [Formula: see text] exhibits a tetragonal-to-orthorhombic phase transition consistent with ferroquadrupole order of the Yb ions and go on to show that elastoresistivity measurements can indeed provide a clear window on the diverging nematic susceptibility in this system. This material provides an arena in which to study the causes and consequences of electronic nematicity.


Assuntos
Germânio/química , Rubídio/química , Supercondutividade , Itérbio/química
8.
Luminescence ; 37(7): 1048-1056, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35411678

RESUMO

A facile method was used for the synthesis of peanut-shaped very emissive NaGdF4 :Yb, Er upconversion nanospheres (UCNSs) at lower temperatures with uniform size distribution. Crystallographic structure, phase purity, morphology, thermal robustness, biocompatibility, colloidal stability, surface chemistry, optical properties, and luminesce properties were explored by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), zeta potential, thermogravimetric/differential thermal analysis (TGA/DTA), Fourier-transform infrared (FTIR), ultraviolet (UV)-visible and photoluminescence spectroscopic tools. XRD pattern verified the construction of a single-phase, highly-crystalline NaGdF4 phase with a hexagonal structure. Peanut-shaped morphology of the sample was obtained from SEM micrographs which were validated from high-resolution TEM images, to have an equatorial diameter of 170 to 200 nm and a length of 220 to 230 nm, with irregular size, monodispersed, porous structure, and rough surface of the particles. The positive zeta potential value exhibited good biocompatibility along with high colloidal stability as observed from the absorption spectrum. The prepared UCNSs revealed high dispersibility, irregular size peanut-shaped morphology, rough surface, good colloidal stability, and excellent biocompatibility in aqueous media. A hexagonal phase NaGdF4 doped with ytterbium (Yb) and erbium (Er) UCNSs revealed the characteristics of highly dominant emissions located at 520-525, 538-550, and 659-668 nm corresponding to the 2 H11/2 → 4 I15/2 , 4 S3/2 → 4 I15/2 , and 4 F9/2 → 4 I15/2 transition of Er3+ ions, respectively, as a result of energy transfer from sensitizer Yb3+ ion to emitter Er3+ ion.


Assuntos
Érbio , Nanosferas , Arachis , Érbio/química , Difração de Raios X , Itérbio/química
9.
J Am Chem Soc ; 143(36): 14907-14915, 2021 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-34469145

RESUMO

Chemotherapy can induce toxicity in the central and peripheral nervous systems and result in chronic adverse reactions that impede continuous treatment and reduce patient quality of life. There is a current lack of research to predict, identify, and offset drug-induced neurotoxicity. Rapid and accurate assessment of potential neuropathy is crucial for cost-effective diagnosis and treatment. Here we report dynamic near-infrared upconversion imaging that allows intraneuronal transport to be traced in real time with millisecond resolution, but without photobleaching or blinking. Drug-induced neurotoxicity can be screened prior to phenotyping, on the basis of subtle abnormalities of kinetic characteristics in intraneuronal transport. Moreover, we demonstrate that combining the upconverting nanoplatform with machine learning offers a powerful tool for mapping chemotherapy-induced peripheral neuropathy and assessing drug-induced neurotoxicity.


Assuntos
Transporte Biológico/fisiologia , Substâncias Luminescentes/química , Nanopartículas Metálicas/química , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Síndromes Neurotóxicas/metabolismo , Animais , Antineoplásicos/efeitos adversos , Fluoretos/química , Gânglios Espinais/citologia , Neurônios/efeitos dos fármacos , Paclitaxel/efeitos adversos , Ratos Sprague-Dawley , Máquina de Vetores de Suporte , Túlio/química , Vincristina/efeitos adversos , Itérbio/química , Ítrio/química
10.
RNA ; 25(2): 173-192, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30409785

RESUMO

Precise knowledge of Mg2+ inner-sphere binding site properties is vital for understanding the structure and function of nucleic acid systems. Unfortunately, the PDB, which represents the main source of Mg2+ binding sites, contains a substantial number of assignment issues that blur our understanding of the functions of these ions. Here, following a previous study devoted to Mg2+ binding to nucleobase nitrogens, we surveyed nucleic acid X-ray structures from the PDB with resolutions ≤2.9 Å to classify the Mg2+ inner-sphere binding patterns to nucleotide carbonyl, ribose hydroxyl, cyclic ether, and phosphodiester oxygen atoms. From this classification, we derived a set of "prior-knowledge" nucleobase Mg2+ binding sites. We report that crystallographic examples of trustworthy nucleobase Mg2+ binding sites are fewer than expected since many of those are associated with misidentified Na+ or K+ We also emphasize that binding of Na+ and K+ to nucleic acids is much more frequent than anticipated. Overall, we provide evidence derived from X-ray structures that nucleobases are poor inner-sphere binders for Mg2+ but good binders for monovalent ions. Based on strict stereochemical criteria, we propose an extended set of guidelines designed to help in the assignment and validation of ions directly contacting nucleobase and ribose atoms. These guidelines should help in the interpretation of X-ray and cryo-EM solvent density maps. When borderline Mg2+ stereochemistry is observed, alternative placement of Na+, K+, or Ca2+ must be considered. We also critically examine the use of lanthanides (Yb3+, Tb3+) as Mg2+ substitutes in crystallography experiments.


Assuntos
Bases de Dados de Proteínas , Magnésio/química , RNA Catalítico/química , Térbio/química , Itérbio/química , Sítios de Ligação/fisiologia , Cálcio/química , Domínio Catalítico , Cristalografia por Raios X , Potássio/química , Ribossomos/genética , Sódio/química
11.
Photochem Photobiol Sci ; 20(3): 401-420, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33721273

RESUMO

In this work, we report on the synthesis of a new-age reusable visible-light photocatalyst using a heterojunction nanocomposite of W6+/Yb3+ on a mixed-phase mesoporous network of monolithic TiO2. The structural properties of the monolithic photocatalysts are characterized using p-XRD, SEM-EDAX, TEM-SAED, XPS, PLS, UV-Vis-DRS, FT-IR, micro-Raman, TG-DTA, and N2 isotherm analysis. The electron microscopic analysis reveals a mesoporous network of ordered worm-like monolithic design, with a polycrystalline mixed-phase (anatase/rutile) TiO2 composite, as indicated by diffraction studies. The UV-Vis-DRS analysis reveals a redshift in the light absorption characteristics of the mixed-phase TiO2 monolith as a function of W6+/Yb3+ co-doping. It is observed that the use of (8.0 mol%)W6+/0.4 (mole%)Yb3+ co-doped monolithic TiO2 photocatalyst, with an energy bandgap of 2.77 eV demonstrates superior visible-light photocatalysis, which corroborates with the PLS studies in terms of voluminous e-/h+ pair formation. The practical application of the photocatalyst has been investigated through a time-dependent dissipation of enrofloxacin, a widely employed antimicrobial drug, and its degradation pathway has been monitored by LC-MS-ESI and TOC analysis. The impact of physio-chemical parameters such as solution pH, sensitizers, drug concentration, dopant/codopant stoichiometry, catalyst quantity, and light intensity has been comprehensively studied to monitor the process efficiency.


Assuntos
Enrofloxacina/química , Nanocompostos/química , Poluentes Químicos da Água/química , Catálise , Cromatografia Líquida de Alta Pressão , Enrofloxacina/análise , Concentração de Íons de Hidrogênio , Luz , Espectroscopia Fotoeletrônica , Fotólise , Espectrometria de Massas por Ionização por Electrospray , Titânio/química , Tungstênio/química , Poluentes Químicos da Água/análise , Itérbio/química
12.
Inorg Chem ; 60(8): 5764-5770, 2021 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-33829775

RESUMO

Two NIR luminescent Zn(II)/Cd(II)-Yb(III) complexes were obtained by the use of a Schiff base ligand with a binaphthyl backbone. Cd(II)-Yb(III) complex 2 has a triangular structure and exhibits interesting luminescent sensing activity to antibiotics, in particular to ciprofloxacin (CPFX) and norfloxacin (NFX) due to the inner filter effect. The limits of the detection of 2 to CPFX and NFX are 0.18 and 0.36 µM, respectively, and the fluorescence sensitivity is not changed with the existence of other antibiotics tested in this study.


Assuntos
Antibacterianos/análise , Cádmio/química , Fluoroquinolonas/análise , Substâncias Luminescentes/química , Itérbio/química , Zinco/química , Raios Infravermelhos , Substâncias Luminescentes/síntese química , Medições Luminescentes , Estrutura Molecular , Bases de Schiff/química
13.
Nanotechnology ; 32(47)2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-33618335

RESUMO

In this work we adapt rare-earth-ion-doped NaYF4nanoparticles coated with a silicon oxide shell (NaYF4:20%Yb,0.2%Tm@SiO2) for biological and medical applications (for example, imaging of cancer cells and therapy at the nano level). The wide upconversion emission range under 980 nm excitation allows one to use the nanoparticles for cancer cell (4T1) photodynamic therapy (PDT) without a photosensitizer. The reactive oxygen species (ROS) are generated by Tm/Yb ion upconversion emission (blue and UV light). Thein vitroPDT was tested on 4T1 cells incubated with NaYF4:20%Yb,0.2%Tm@SiO2nanoparticles and irradiated with NIR light. After 24 h, cell viability decreased to below 10%, demonstrating very good treatment efficiency. High modification susceptibility of the SiO2shell allows for attachment of biological molecules (specific antibodies). In this work we attached the anti-human IgG antibody to silane-PEG-NHS-modified NaYF4:20%Yb,0.2%Tm@SiO2nanoparticles and a specifically marked membrane model by bio-conjugation. Thus, it was possible to perform a selective search (a high-quality optical method with a very low-level organic background) and eventually damage the targeted cancer cells. The study focuses on therapeutic properties of NaYF4:20%Yb,0.2%Tm@SiO2nanoparticles and demonstrates, upon biological functionalization, their potential for targeted therapy.


Assuntos
Nanopartículas , Neoplasias , Fotoquimioterapia , Fármacos Fotossensibilizantes , Espécies Reativas de Oxigênio/metabolismo , Animais , Linhagem Celular Tumoral , Feminino , Camundongos , Nanopartículas/química , Nanopartículas/uso terapêutico , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacocinética , Fármacos Fotossensibilizantes/farmacologia , Dióxido de Silício/química , Dióxido de Silício/farmacocinética , Dióxido de Silício/farmacologia , Túlio/química , Túlio/farmacocinética , Túlio/farmacologia , Itérbio/química , Itérbio/farmacocinética , Itérbio/farmacologia , Ítrio/química , Ítrio/farmacocinética , Ítrio/farmacologia
14.
J Fluoresc ; 31(2): 541-550, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33452637

RESUMO

Currently, upconversion nanoparticles (UCNPs) implanted as a contrast agent for optical coherence tomography (OCT) system due to its biocompatibility, anti-stock emission, narrow emission bandwidth non-photobleaching effects etc., but it was not used as multi model imaging probe. We synthesized multimodal imaging probe having upconversion property along with paramagnetic property and used as dual contrast agents for Photothermal Optical Coherence Tomography (PTOCT) and Magnetomotive Optical Coherence Tomography (MMOCT). The synthesized Gd2O3:Er3+/Yb3+ UCNPs shows the bright yellow upconversion emission, biocompatibility with hydrophilic property. A custom built SSOCT setup modified for PTOCT and MMOCT imaging along with custom MATLAB algorithm for signal extraction. A dynamic study was performed with synthesized UCNPs as an imaging probe and functional OCT system for targeted imaging. This shows the utility of the Gd2O3:Er3+/Yb3+ UCNPs as molecular probe for targeted imaging applications.


Assuntos
Meios de Contraste/química , Érbio/química , Gadolínio/química , Nanopartículas/química , Tomografia de Coerência Óptica , Itérbio/química , Algoritmos , Células Cultivadas , Humanos
15.
Anal Bioanal Chem ; 413(5): 1363-1371, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33388932

RESUMO

Novel polyepinephrine-modified NaYF4:Yb,Tm upconversion luminescent nanoparticles (UCNP@PEP) were prepared via the self-polymerization of epinephrine on the surfaces of the UCNPs for selective sensing of Fe3+ inside a cell and for intracellular imaging. The proposed UCNP@PEP probe is a strong blue light emitter (λmax = 474 nm) upon exposure to an excitation wavelength of 980 nm. The probe was used for detecting Fe3+ owing to the complexation reaction between UCNP@PEP and Fe3+, resulting in reduced upconversion luminescence (UCL) intensity. The proposed probe has a detection limit of 0.2 µM and a good linear range of 1-10 µM for sensing Fe3+ ions. Moreover, the UCNP@PEP probe displays high cell viability (90%) and is feasible for intracellular imaging. The ability of the probe to sense Fe3+ in a human serum sample was tested and shows promising output for diagnostic purposes. The prepared UCNP@PEP probe was characterized by using UV-visible (UV-Vis) absorption spectrometry, fluorescence (FL) spectrometry, field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR).


Assuntos
Cátions/análise , Epinefrina/química , Fluoretos/química , Ferro/análise , Nanopartículas/química , Itérbio/química , Ítrio/química , Cátions/sangue , Células HeLa , Humanos , Ferro/sangue , Luminescência , Microscopia de Fluorescência , Imagem Óptica , Polímeros/química
16.
Molecules ; 26(4)2021 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-33671148

RESUMO

NaYF4:Er,Yb upconversion luminescent nanoparticles (UCNPs) were prepared by hydrothermal methods at 180 °C for 24 h. The X-ray diffraction (XRD) and TEM (transmission electron microscopy) images show that the resulting 60 nm UCNPs possess a hexagonal structure. In this work, maleic anhydride (MA) was grafted on the surface of UCNPs to induce hydrophilic properties. The photoluminescence spectra (PL) show upconversion emissions centered around 545 nm and 660 nm under excitation at 980 nm. The luminescent inks, including UCNPs@MA, polyvinyl alcohol (PVA), deionized water (DI), and ethylene glycol (EG), exhibit suitable properties for screen printing, such as high stability, emission intensity, and tunable dynamic viscosity. The printed patterns with a height of 5 mm and a width of 1.5 mm were clearly observed under the irradiation of a 980 nm laser. Our strategy provides a new route for the controlled synthesis of hydrophilic UCNPs, and shows that the UCNPs@MAs have great potential in applications of anti-counterfeiting packing.


Assuntos
Fluoretos/química , Química Verde , Tinta , Luminescência , Anidridos Maleicos/química , Nanopartículas/química , Análise Espectral , Itérbio/química , Ítrio/química , Érbio/química , Fenômenos Ópticos , Polímeros/química , Espectroscopia de Infravermelho com Transformada de Fourier , Vibração , Difração de Raios X
17.
Angew Chem Int Ed Engl ; 60(10): 5453-5458, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33244829

RESUMO

It remains an unanswered question whether the flux of K+ and H+ in lysosomes are correlated due to difficulties in simultaneously imaging these two ions. This question is of great value for understanding lysosomal acidification. Herein, we designed DNA quadruplex and triplex based luminescent nanosensors that can, respectively monitor K+ and pH in lysosomal lumen. Each sensor contained an upconversion nanoparticle luminophore and a gold nanoparticle quencher, producing green and blue luminescence signals for K+ and H+ , respectively. The sensors were tested in buffers showing dynamic ranges of 5 to 200 mM K+ and pH 5.0 to 8.2. Co-imaging using these two sensors in cells indicated that the influx of H+ was accompanied with the efflux of K+ , solving this long-standing question of the lysosomal biochemistry.


Assuntos
Técnicas Biossensoriais/métodos , DNA/química , Lisossomos/metabolismo , Nanopartículas Metálicas/química , Potássio/análise , Érbio/química , Fluoretos/química , Quadruplex G , Ouro/química , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Microscopia Confocal , Microscopia de Fluorescência , Itérbio/química , Ítrio/química
18.
Angew Chem Int Ed Engl ; 60(44): 23574-23577, 2021 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-34387934

RESUMO

Drug-loaded liposomes are typical examples of nanomedicines. We show here that doxorubicin, the anti-cancer agent in the liposomal drug Doxil, can sensitize Ytterbium (Yb3+ ) and generate its near-infrared (NIR) emission. When doxorubicin and amphiphilic Yb3+ chelates are incorporated into liposomes, the sensitized emission of Yb3+ is dependent on the integrity of the particles, which can be used to monitor drug release. We also established the first demonstration that the NIR Yb3+ emission signal is observable in living mice following intratumoral injection of the Yb3+ -doxorubicin-liposomes, using a commercial macroscopic setup equipped with a NIR camera.


Assuntos
Antibióticos Antineoplásicos/química , Neoplasias da Mama/diagnóstico por imagem , Doxorrubicina/análogos & derivados , Luminescência , Itérbio/química , Animais , Linhagem Celular Tumoral , Doxorrubicina/química , Liberação Controlada de Fármacos , Feminino , Raios Infravermelhos , Lipossomos/química , Imageamento por Ressonância Magnética , Camundongos , Estrutura Molecular , Polietilenoglicóis/química
19.
Anal Chem ; 92(1): 1292-1300, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31855416

RESUMO

We demonstrate an effective approach to realize active and real-time temperature monitoring around the gold nanobipyramids (AuNBPs)-labeled cancer cell under 808 nm laser irradiation by combining optical tweezers and temperature-sensitive upconversion microparticles (UCMPs). On the one hand, the aptamer-modified AuNBPs that absorb laser at 808 nm not only act as an excellent photothermal reagent but also accurately and specifically bind the target cancer cells. On the other hand, the single optically trapped NaYF4:Yb3+, Er3+ UCMPs with a 980 nm laser exhibit temperature-dependent luminescence properties, where the intensity ratio of emission 525 and 547 nm varies with the ambient temperature. Therefore, real-time temperature variation monitoring is performed by 3D manipulation of the trapped single UCMP to control its distance from the AuNBPs-labeled cancer cell while being photothermally killed. The results show distance-related thermal propagation because the temperature increase reaches as high as 10 °C at a distance of 5 µm from the cell, whereas the temperature difference drops rapidly to 5 °C when this distance increases to 15 µm. This approach shows that the photothermal conversion from AuNBPs is sufficient to kill the cancer cells, and the temperature increase can be controlled within the micrometer level at a certain period of time. Overall, we present a micrometer-size thermometer platform and provide an innovative strategy to measure temperature at the micrometer level during photothermal killing of cancer cells.


Assuntos
Luminescência , Nanopartículas/química , Pinças Ópticas , Compostos Organoáuricos/química , Fototerapia , Temperatura , Células A549 , Células Cultivadas , Érbio/química , Células HEK293 , Calefação , Humanos , Lasers , Imagem Óptica , Compostos Organoáuricos/síntese química , Fatores de Tempo , Itérbio/química , Ítrio/química
20.
Anal Chem ; 92(1): 1470-1476, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31762255

RESUMO

This work reports a ZIF-8 (ZIF: Zeolitic Imidazolate Framework)-assisted NaYF4:Yb,Tm@ZnO upconverter for the photoelectrochemical (PEC) biosensing of carcinoembryonic antigen (CEA) under near-infrared (NIR) irradiation on a homemade 3D-printed device with DNA walker-based amplification strategy. The composite photosensitive material NaYF4:Yb,Tm@ZnO, as converter to transfer NIR import to photocurrent output, was driven from annealed NaYF4:Yb,Tm@ZIF-8. Yb3+ and Tm3+-codoped NaYF4 (NaYF4:Yb,Tm) converted NIR excitation into UV emission, matching with the absorption of ZnO for in situ excitation to generate the photocurrent. Upon target CEA introduction, the swing arm of DNA walker including the sequence of CEA aptamer carried out the sandwiched bioassembly with CEA capture aptamer on the G-rich anchorage DNA tracks-functionalized magnetic beads. Thereafter, DNA walker was triggered, and the swing arm DNA was captured by the G-rich anchorage DNA according to partly complementary pairing and Exonuclease III (Exo III) consumed anchorage DNA by a burnt-bridge mechanism to go into the next cycle. The released guanine (G) bases from DNA walker enhanced the photocurrent response on a miniature homemade 3D-printed device consisting of the detection cell, dark box, and light platform. Under optimal conditions, NaYF4:Yb,Tm@ZnO-based NIR light-driven PEC biosensor presented high sensitivity and selectivity for CEA sensing with a detection limit of 0.032 ng mL-1. Importantly, our strategy provides a new horizon for the development of NIR-based PEC biosensors in the aspect of developing MOF-derived photoelectric materials, flexible design of a 3D-printed device, and effective signal amplification mode.


Assuntos
Técnicas Biossensoriais , DNA/metabolismo , Técnicas Eletroquímicas , Exodesoxirribonucleases/metabolismo , DNA/química , Exodesoxirribonucleases/química , Fluoretos/química , Fluoretos/metabolismo , Humanos , Raios Infravermelhos , Processos Fotoquímicos , Túlio/química , Túlio/metabolismo , Itérbio/química , Itérbio/metabolismo , Ítrio/química , Ítrio/metabolismo , Zeolitas/química , Zeolitas/metabolismo , Óxido de Zinco/química , Óxido de Zinco/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA