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1.
Int J Nanomedicine ; 15: 1409-1420, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32184595

RESUMO

Background: Photothermal therapy with accurate and real-time temperature detection is desired in clinic. Upconversion nanocrystals (UCNs) are candidate materials for simultaneous temperature detection and photothermal agents carrying. However, the weak luminescence and multiple laser excitations of UCNs limit their application in thermal therapy. Materials and Methods: NaYF4:Yb3+,Er3+,Nd3+, PL-PEG-NH2, IR-806 and folic acid are selected as structural components. A nanoprobe (NP) integrated with efficient photothermal conversion and sensitive temperature detection capabilities is synthesized for precise photothermal therapy. The probes are based on near-infrared upconversion nanocrystals doped with Yb, Er and Nd ions, which can be excited by 808 nm light. IR-806 dye molecules are modified on the surface as molecular antennas to strongly absorb near-infrared photons for energy transfer and conversion. Results: The results show that under an 808 nm laser irradiation upconversion luminescence of the nanocrystals is enhanced based on both the Nd ion absorption and the FRET energy transfer of IR-806. The luminescence ratio at 520 and 545 nm is calculated to accurately monitor the temperature of the nanoparticles. The temperature of the nanoprobes increases significantly through energy conversion of the molecular antennas. The nanoparticles are found successfully distributed to tumor cells and tumor tissue due to the modification of the biocompatible molecules on the surface. Tumor cells can be killed efficiently based on the photothermal effect of the NPs. Under the laser irradiation, temperature at mouse tumor site increases significantly, tissue necrosis and tumor cell death can be observed. Conclusion: Precision photothermal therapy can thus be achieved by highly efficient near-infrared light absorption and accurate temperature monitoring, making it promising for tumor treatment, as well as the biological microzone temperature detection.


Assuntos
Nanopartículas/química , Fototerapia/métodos , Termografia/métodos , Animais , Linhagem Celular Tumoral , Érbio/química , Feminino , Raios Infravermelhos , Lasers , Luminescência , Neoplasias Mamárias Experimentais/terapia , Camundongos Endogâmicos BALB C , Neodímio/química , Temperatura , Itérbio/química , Ítrio/química
2.
Chemistry ; 26(14): 3145-3151, 2020 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-31886920

RESUMO

Ongoing demand for accurate self-calibrated noninvasive thermometers for micro-/nano-scale applications, particular biomedical diagnosis, is driving the development of temperature sensors. Here a new type of lanthanide metal-organic framework having near-infrared absorption and near-infrared emission features is presented, and it is based on efficient Nd3+ -to-Yb3+ energy transfer in 808 nm photoexcitation. The results show that the ratiometric parameter of Nd0.5 Yb0.5 TPTC (TPTC= 1,1':4',1''-terphenyl]-3,3'',5,5''-tetracarboxylic acid) can deliver good exponential-type luminescence response to temperature in the physiological regime (293-328 K) with high relative sensitivity and accurate temperature resolution, as well as good biocompatibility and chemical stability. Such lanthanide-based materials are especially useful in biomedical applications.


Assuntos
Complexos de Coordenação/química , Corantes Fluorescentes/química , Estruturas Metalorgânicas/química , Neodímio/química , Itérbio/química , Transferência Ressonante de Energia de Fluorescência , Raios Infravermelhos , Ligantes , Estrutura Molecular , Temperatura , Termômetros
3.
Molecules ; 24(22)2019 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-31717490

RESUMO

(1) Background: Nanomedicine has recently emerged as a promising field, particularly for cancer theranostics. In this context, nanoparticles designed for imaging and therapeutic applications are of interest. We, therefore, studied the encapsulation of upconverting nanoparticles in mesoporous organosilica nanoparticles. Indeed, mesoporous organosilica nanoparticles have been shown to be very efficient for drug delivery, and upconverting nanoparticles are interesting for near-infrared and X-ray computed tomography imaging, depending on the matrix used. (2) Methods: Two different upconverting-based nanoparticles were synthesized with Yb3+-Er3+ as the upconverting system and NaYF4 or BaLuF5 as the matrix. The encapsulation of these nanoparticles was studied through the sol-gel procedure with bis(triethoxysilyl)ethylene and bis(triethoxysilyl)ethane in the presence of CTAB. (3) Results: with bis(triethoxysilyl)ethylene, BaLuF5: Yb3+-Er3+, nanoparticles were not encapsulated, but anchored on the surface of the obtained mesoporous nanorods BaLuF5: Yb3+-Er3+@Ethylene. With bis(triethoxysilyl)ethane, BaLuF5: Yb3+-Er3+ and NaYF4: Yb3+-Er3+nanoparticles were encapsulated in the mesoporous cubic structure leading to BaLuF5: Yb3+-Er3+@Ethane and NaYF4: Yb3+-Er3+@Ethane, respectively. (4) Conclusions: upconversion nanoparticles were located on the surface of mesoporous nanorods obtained by hydrolysis polycondensation of bis(triethoxysilyl)ethylene, whereas encapsulation occurred with bis(triethoxysilyl)ethane. The later nanoparticles NaYF4: Yb3+-Er3+@Ethane or BaLuF5: Yb3+-Er3+@Ethane were promising for applications with cancer cell imaging or X-ray-computed tomography respectively.


Assuntos
Nanopartículas/química , Compostos de Organossilício/química , Sistemas de Liberação de Medicamentos/métodos , Érbio/química , Etano/química , Fluoretos/química , Hidrólise , Nanomedicina/métodos , Nanotubos/química , Tecnologia Farmacêutica/métodos , Itérbio/química , Ítrio/química
4.
ACS Appl Mater Interfaces ; 11(44): 41100-41108, 2019 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-31618568

RESUMO

Upconversion nanoparticles (UCNPs) are prospective platforms for bioimaging and phototherapy, but a critical bottleneck is the limited brightness due to the faint absorptivity of lanthanide ions and the low quantum yield. To circumvent this problem, we herein propose our strategy to reconstruct the energy cascade of UCNPs using semiconductor quantum dots (QDs) as light sensitizer of Nd3+/Yb3+ codoped UCNPs. Ag2Se QDs with strong absorption at 808 nm acted as efficient antenna and transferred their energy to Yb3+ via a resonance energy transfer process, significantly enhancing the luminescence of UCNPs. This nanocomposite was then combined with Rose Bengal and applied for photodynamic therapy. Both in vitro and in vivo studies revealed the introduction of QDs improved the therapeutic performance remarkably. Our study suggests Ag2Se QDs with excellent photophysical properties can be promising agents to overcome the shortcomings of UCNPs and further strengthen their applications.


Assuntos
Nanopartículas de Magnetita/química , Neoplasias/tratamento farmacológico , Fármacos Fotossensibilizantes/uso terapêutico , Pontos Quânticos/química , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Transferência de Energia , Humanos , Raios Infravermelhos , Nanopartículas de Magnetita/toxicidade , Camundongos , Camundongos Nus , Microscopia Confocal , Neodímio/química , Neoplasias/patologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Pontos Quânticos/toxicidade , Rosa Bengala/química , Rosa Bengala/farmacologia , Rosa Bengala/uso terapêutico , Semicondutores , Itérbio/química
5.
Ultrason Sonochem ; 59: 104734, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31479886

RESUMO

Currently near-infrared (NIR) luminescence of lanthanide ions has received great attention because of their unique emissions in the near-infrared region (800-1700 nm). These NIR luminescent materials behave excellent applications in many fields such as sensors and probes in optical amplification, laser systems, biological systems and organic light-emitting diodes. In this work, two new near-infrared (NIR) emission three-dimensional (3D) YbIII and NdIII cluster-based coordination materials, namely {[Yb2(L)2(DMF)(H2O)4]·(DMF)2 (H2O)}n (NIR-MOF 1) and [Nd(L)(DMF)2]n (NIR-MOF 2) (H3L = terphenyl-3,4″,5-tricarboxylic acid) have been synthesized through the facile sono-chemical preparation methods. Both the near-infrared materials 1 and 2 have been characterized by single crystal X-ray diffraction, powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). Further the mixed-lanthanide near-infrared emission material Nd0.35Yb0.65L (NIR-MOF 3) can also be prepared under the sono-chemical conditions. NIR-MOF 3 can be successfully applied as the ratiometric NIR-MOF-based thermometer, which should origin from the emission intensity ratio between Yb3+ (976 nm) and Nd3+ (1056 nm) in the temperature range of 308-348 K. Besides these, the micro-morphologies of NIR-MOF 1 can be deliberately tuned through different sono-chemical reaction factors (reaction time, reaction temperature and sono-chemical powers). These tuned nano-sized materials NIR-MOF 1 (100 W, 80 min) can be utilized as the fluorescent sensing material to distinguish furazolidone and sulfasalazine from other antibiotics. At the same time, NIR-MOF 2 can be applied as the first example of MOFs-based sensors for discriminating l-arginine from other amino acids through the "turn-on" mode in the near-infrared emission region.


Assuntos
Antibacterianos/análise , Arginina/análise , Técnicas de Química Analítica/instrumentação , Raios Infravermelhos , Neodímio/química , Ondas Ultrassônicas , Itérbio/química , Antibacterianos/química , Arginina/química , Furazolidona/análise , Furazolidona/química , Cinética , Limite de Detecção , Modelos Moleculares , Conformação Molecular , Compostos Organometálicos/química , Solventes/química , Sulfassalazina/análise , Sulfassalazina/química , Temperatura
6.
Mater Sci Eng C Mater Biol Appl ; 104: 109940, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31500050

RESUMO

Well-dispersed Ag nanowires and PVP-modified BaGdF5: Yb3+, Er3+ spherical nanoparticles were prepared by simple solvothermal and hydrothermal method, and they were further combined to obtain photo-thermal-magnetic multifunctional Ag/BaGdF5: Yb3+, Er3+ nanocomposites. Under NIR laser irradiation, monodispersed rare-earth fluoride BaGdF5: Yb3+, Er3+ in nanocomposite exhibit good upconversion fluorescent. Meanwhile, under the action of an external magnetic field, the nanocomposite also exhibits good magnetic properties and excellent contrast efficiency by CT/MR imaging. The NCs possess good structure and photothermal stability at multiple cycles due to that Ag nanowires are modified by polyvinyl pyrrolidone and sodium citrate. The biocompatibility and low toxicity of NCs are also remarkable. Importantly, the unique linear morphology of Ag particles can achieve high efficiency conversion between light and heat. Furthermore, in vitro tests also confirm the high efficiency of photothermal therapy for cancer cells.


Assuntos
Fluoretos/química , Fluoretos/uso terapêutico , Nanocompostos/química , Nanopartículas/química , Nanofios/química , Neoplasias/tratamento farmacológico , Prata/química , Linhagem Celular Tumoral , Corantes Fluorescentes/química , Células HeLa , Células Hep G2 , Humanos , Luz , Luminescência , Metais Terras Raras/química , Itérbio/química
7.
Opt Lett ; 44(15): 3633-3636, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31368930

RESUMO

The development of optical thermometers operating within the first biological window (650-1000 nm) has drawn great interest lately in the biological and medical fields. Here a new type of luminescent thermometer relying on the intensity ratio between G41-F43 (652 nm) and F2,33-H63(691 nm) transitions in Tm3+/Yb3+:BaMoO4 phosphor is reported under 980 nm excitation. The thermometry is found to be independent on the excitation power, benefiting the reduction of the measurement error. Moreover, it exhibits extremely high absolute sensitivity ranging from 210.5×10-4 to 1034.5×10-4 K-1 in 298-498 K. The maximal relative sensitivity and temperature resolutions (1.36% K-1 and 0.37 K, respectively) are also among the highest values of those previous thermometric materials. This Letter provides guidance in selecting the suitable emission bands to construct the ratiometric luminescent thermometers with high performance.


Assuntos
Bário/química , Luminescência , Molibdênio/química , Termometria/métodos , Túlio/química , Itérbio/química , Temperatura
8.
Dalton Trans ; 48(34): 12850-12857, 2019 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-31393486

RESUMO

Even though various theranostic agents have been exploited for effective cancer therapy over the years, appropriate design and fabrication of theranostic agents with simple composition, convenient preparation, high theranostic efficiency and minimal side effects on non-cancer cells are still urgently needed. Herein, multifunctional NaYF4:Yb,Er@polyelectrolyte (PE3)@Fe3O4 nanocomposites, with upconversion luminescence, superparamagnetism and photothermal performance, are prepared by a layer-by-layer self-assembly technique. Compared with Fe3O4 nanoparticles (NPs), the nanocomposites exhibited nearly 2-fold strong absorption at 808 nm, and thus resulted in an enhanced near-infrared photothermal effect. With the assistance of an external magnetic field, a high sensitivity of upconversion fluorescence imaging and a low cancer cell viability of 13.9% were achieved under 808 nm laser irradiation. It is expected that multifunctional NaYF4:Yb,Er@PE3@Fe3O4 nanocomposites would pave the way toward promoting the clinical applications of theranostic nanomaterials.


Assuntos
Érbio/química , Campos Magnéticos , Nanocompostos , Imagem Óptica/métodos , Fototerapia/métodos , Itérbio/química , Ítrio/química , Animais , Linhagem Celular Tumoral , Luminescência , Camundongos
9.
Anal Chim Acta ; 1079: 200-206, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31387712

RESUMO

Arginine is an important amino acid in humankind bodies and is of essential clinical significance. This paper presents a novel bioprobe based on fluorescence resonance energy transfer (FRET), which can be used to detect arginine efficiently and economically. In this bioprobe system, positively charged up-conversion phosphor NaYF4 (NYF) acts as energy donor, and negatively charged gold nanoparticle (AuNP) acts as energy acceptor. The oppositely charged donor and acceptor come into close proximity through electrostatic attraction effect, which results in the occurrence of FRET between NYF and AuNP. The FRET process is thus in the "on" state, meanwhile the system is in the "off" state, and the emitting light of NYF quenched. When positively charged arginine is added into the system, the guanidyl of arginine binds to AuNP and leads to the negatively charged AuNP becomes positively charged one, and the AuNP separates from NYF because of the electrostatic repulsion. The FRET process is blocked and the system switches to the "on" state because the distance between NYF and AuNP becomes longer. In the "on" state, the intensity of the restored emitting light is proportional to the concentration of arginine. This approach brings a good linear relationship between the fluorescence intensity and the concentration of arginine in the concentration range of 14.42-115.04 µM. The limit of detection is as low as 2.9 µM. A new method for quantitative determination of arginine by just measuring the fluorescence intensity of the system is established.


Assuntos
Arginina/sangue , Técnicas Biossensoriais/métodos , Fluoretos/química , Nanopartículas Metálicas/química , Ítrio/química , Érbio/química , Fluorescência , Transferência Ressonante de Energia de Fluorescência/métodos , Ouro/química , Humanos , Limite de Detecção , Espectrometria de Fluorescência/métodos , Itérbio/química
10.
Talanta ; 204: 792-801, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31357366

RESUMO

Selective separation of heme proteins and peptides from complicated biological samples before comprehensive identification and characterization of intact biomolecules which are low stoichiometry is indispensable for ongoing proteomics. Here, three magnetic mesoporous rare-earth silicate (rare-earth = Er, Tm, Yb) microspheres prepared by facile solvothermal method were used as novel adsorbents for the selective isolation of bovine hemoglobin (BHb), and magnetic mesoporous ytterbium silicate showed apparent adsorption efficiency in isolating BHb with a adsorption capacity of 304.4 mg/g after the comparison. The retained BHb could be eluted by using Na2CO3 as stripping reagent. Meanwhile, Circular dichroism spectra illustrated that the microspheres posed no effect on the secondary structure of BHb. The resultant magnetic particles were characterized by transmission electron microscope, scanning electron microscope, x-ray powder diffraction, vibrating sample magnetometer, Fourier transform infrared spectroscopy, N2 adsorption-desorption isotherm and zeta potential. The as-prepared magnetic microspheres showed high specificity for the separation of BHb from bovine plasma as corroborated by SDS-PAGE and MALDI-TOF MS analysis, which would be expected to possess potential application in isolation of other heme proteins in complex biological samples.


Assuntos
Hemoglobinas/isolamento & purificação , Microesferas , Silicatos/química , Adsorção , Animais , Bovinos , Eletroforese em Gel de Poliacrilamida , Érbio/química , Hemoglobinas/análise , Hemoglobinas/química , Fenômenos Magnéticos , Nanopartículas de Magnetita/química , Espectrometria de Massas , Túlio/química , Itérbio/química
11.
Mikrochim Acta ; 186(8): 502, 2019 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-31270621

RESUMO

The balance between free oxygen radicals and antioxidant defense systems is usually assessed by an antioxidant capacity assay. A rapid and sensitive antioxidant capacity assay is described here. It is making use of NaYF4:Yb/Er@NaYF4 core-shell upconversion nanoparticles (UCNPs) and potassium permanganate (KMnO4). In this strategy, added KMnO4 reduces the green (540 nm) emission of the UCNPs (under 980 nm photoexcitation) due to an inner filter effect. The antioxidants cysteine, ascorbic acid and glutathione (GSH) reduce the intense purple color of KMnO4 because it is reduced to Mn(II) ion. Hence, the green upconversion fluorescence is restored after the addition of antioxidants. Figures of merit for this assay (for the case of GSH) include a detection limit of 3.3 µM, a detection range that extends from 10 µM to 2.5 mM, and an assay time of a few seconds. The assay was applied to the evaluation of antioxidant capacity in human plasma samples spiked with GSH and gave satisfactory repeatability and specificity. Graphical abstract Schematic presentation of a fluorometric assay based on inner filter effect (IFE) between upconversion nanoparticles (UCNPs) and potassium permanganate (KMnO4) for the determination of antioxidant capacity in human plasma.


Assuntos
Ácido Ascórbico/análise , Cisteína/análise , Érbio/química , Fluoretos/química , Glutationa/análise , Nanopartículas/química , Permanganato de Potássio/química , Itérbio/química , Ítrio/química , Ácido Ascórbico/sangue , Ácido Ascórbico/química , Técnicas Biossensoriais , Cisteína/química , Fluorometria , Glutationa/sangue , Glutationa/química , Humanos
12.
Dalton Trans ; 48(25): 9291-9302, 2019 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-31166338

RESUMO

The study aims to understand the significance of collective rare earth (RE3+) substitutions in ZrO2 structures for biomedical applications. The RE3+ ions namely Yb3+, Dy3+, Tb3+, Gd3+, Eu3+, and Nd3+ were selected and their concentrations were adjusted to obtain three different combinations. The influence of RE3+ on the crystal structure of ZrO2 alongside the absorption, luminescence, mechanical, magnetic, computed tomography (CT), magnetic resonance imaging (MRI) properties was explored. The concomitant effect of the average ionic size and RE3+ concentration determines the crystallization behavior of ZrO2 at elevated temperatures. The collective RE3+ substitutions exhibit both up-conversion and down-conversion emissions with their respective excitation at 793 and 350 nm. Nevertheless, increment in the concentration of RE3+ is found to be detrimental to the mechanical stability of ZrO2. The collective characteristics of multiple RE3+ demonstrate the potential of the investigated system in multimodal imaging applications. The unique luminescence characteristics of Eu3+ and Tb3+ are promising for fluorescence imaging while the presence of Dy3+, Tb3+, Gd3+ and Nd3+ unveils a paramagnetic response required for MRI. In addition, Dy3+ and Yb3+ contribute to the high X-ray absorption coefficient values suitable for X-ray CT imaging.


Assuntos
Materiais Biocompatíveis/química , Metais Terras Raras/química , Zircônio/química , Disprósio/química , Európio/química , Gadolínio/química , Luminescência , Imagem por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Fenômenos Mecânicos , Neodímio/química , Térbio/química , Tomografia Computadorizada por Raios X , Itérbio/química
13.
Dalton Trans ; 48(28): 10537-10546, 2019 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-31214676

RESUMO

Rare earth ion-doped fluoride upconversion nanoparticles (UCNPs), emerging as a novel class of probes and drug carriers, exhibit superior promise for bio-applications in diagnostics and treatment on account of their strong luminescence, fine biocompatibility, and high drug loading. However, the fine control and manipulation of particle size and the distribution of rare earth ion-doped oxides has remained an insurmountable challenge to date. In this work, we construct and synthesize silica-coated Gd2(WO4)3:Yb3+/Ho3+ nanoparticles by one-pot co-precipitation, with uniform distribution (∼130 nm) and enhanced yellow fluorescence. Particularly, the nanoparticles not only possess outstanding temperature sensing performance at biological temperatures in water by utilizing the fluorescence intensity ratio (FIR) method, but also allow a further serviceable contrast effect in vitro and in vivo based on the prominent T1-weighted magnetic resonance (MR) signal of Gd3+. Compared with cisplatin and platinum(iv) (DSP), the Gd2(WO4)3@SiO2 nanoparticles functionalized with DSP (Gd2(WO4)3@SiO2-Pt-PEG) exert higher lethality against CT26 cells and significantly inhibit the growth of tumors at the same concentration of Pt. This effect occurs through the greater level of cell endocytosis. The lethality value of the latter is 10 times higher than the former after the same length of time according to inductively coupled plasma-mass spectrometry (ICP-MS) results. In short, the monodisperse and strongly fluorescent Gd2(WO4)3@SiO2-Pt-PEG nanoparticles are endowed with dual-mode imaging, temperature sensing and anticancer functions, which provide a significant guide for synthesis and bio-application of lanthanide ion-doped oxides.


Assuntos
Antineoplásicos/farmacologia , Corantes Fluorescentes/farmacologia , Nanopartículas/química , Imagem Óptica , Dióxido de Silício/química , Temperatura , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/química , Gadolínio/química , Hólmio/química , Camundongos , Estrutura Molecular , Relação Estrutura-Atividade , Compostos de Tungstênio/química , Itérbio/química
14.
Med Phys ; 46(7): 2935-2943, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31054163

RESUMO

PURPOSE: To present and quantify the effectiveness of a method for the efficient production of 169 Yb high-dose-rate brachytherapy sources with 27 Ci activity upon clinical delivery, which have about the same dose rate in water at 1 cm from the source center as 10 Ci 192 Ir sources. MATERIALS: A theoretical framework for 169 Yb source activation and reactivation using thermal neutrons in a research reactor and 168 Yb-Yb2 O3 precursor is derived and benchmarked against published data. The model is dependent primarily on precursor 168 Yb enrichment percentage, active source volume of the active element, and average thermal neutron flux within the active source. RESULTS: Efficiency gains in 169 Yb source production are achievable through reactivation, and the gains increase with active source volume. For an average thermal neutron flux within the active source of 1 × 1014  n cm-2  s-1 , increasing the active source volume from 1 to 3 mm3 decreased reactor-days needed to generate one clinic-year of 169 Yb from 256 days yr-1 to 59 days yr-1 , and 82%-enriched precursor dropped from 80 mg yr-1 to 21 mg yr-1 . A resource reduction of 74%-77% is predicted for an active source volume increase from 1 to 3 mm3 . CONCLUSIONS: Dramatic cost savings are achievable in 169 Yb source production costs through reactivation if active sources larger than 1 mm3 are used.


Assuntos
Braquiterapia , Doses de Radiação , Radioquímica/métodos , Radioisótopos/química , Radioisótopos/uso terapêutico , Itérbio/química , Itérbio/uso terapêutico , Benchmarking , Dosagem Radioterapêutica
15.
Molecules ; 24(10)2019 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-31117271

RESUMO

Raman spectra of aqueous Ho3+, Er3+, Tm3+, Yb3+, and Lu3+-perchlorate solutions were measured over a large wavenumber range from 50-4180 cm-1. In the low wavenumber range (terahertz region), strongly polarized Raman bands were detected at 387 cm-1, 389 cm-1, 391 cm-1, 394 cm-1, and 396 cm-1, respectively, which are fairly broad (full widths at half height at ~52 cm-1). These isotropic Raman bands were assigned to the breathing modes, ν1 Ln-O of the heavy rare earth (HRE) octaaqua ions, [Ln(H2O)8]3+. The strong polarization of these bands (depolarization degree ~0) reveals their totally symmetric character. The vibrational isotope effect was measured in Yb(ClO4)3 solutions in H2O and D2O and the shift of the ν1 mode in changing from H2O to D2O further supports the character of the band. The Ln-O bond distances of these HRE ions (Ho3+, Er3+, Tm3+, Yb3+, and Lu3+) follow the order of Ho-O > Er-O > Tm-O > Yb-O > Lu-O which correlates inversely with the band positions of the breathing modes of their corresponding octaaqua ions [Ln(OH2)8]3+. Furthermore, the force constants, kLn-O, were calculated for these symmetric stretching modes. Ytterbium perchlorate solutions were measured over a broad concentration range, from 0.240 mol·L-1 to 2.423 mol·L-1, and it was shown that with increasing solute concentration outer-sphere ion pairs and contact ion pairs were formed. At the dilute solution state (~0.3 mol·L-1), the fully hydrated ions [Yb(H2O)8]3+ exist, while at higher concentrations (CT > 2 mol·L-1), ion pairs are formed. The concentration behavior of Yb(ClO4)3 (aq) shows similar behavior to the one observed for La(ClO4)3(aq), Ce(ClO4)3(aq) and Lu(ClO4)3(aq) solutions. In ytterbium chloride solutions in water and heavy water, representative for the behavior of the other HRE ions, 1:1 chloro-complex formation was detected over the concentration range from 0.422-3.224 mol·L-1. The 1:1 chloro-complex in YbCl3(aq) is very weak, diminishing rapidly with dilution and vanishing at a concentration < 0.4 mol·L-1.


Assuntos
Érbio/química , Hólmio/química , Lutécio/química , Túlio/química , Itérbio/química , Íons/química , Metais Terras Raras/química , Percloratos/química , Soluções/química , Análise Espectral Raman , Água/química
16.
Talanta ; 201: 126-133, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31122402

RESUMO

Upconversion nanoparticle-based lateral flow assays (UCNP-LFAs) have attracted significant attention in point-of-care testing (POCT) applications, due to the long-term photostability and enhanced signal-to-background noise ratio. The existing UCNP-LFAs generally require peripheral equipment for exciting fluorescent signals and reading out fluorescence results, which are generally bulky and expensive. Herein, we developed a miniaturized and portable UCNP-LFA platform, which is composed of a LFA detection system, an UCNP-LFA reader and a smartphone-assisted UCNP-LFA analyzer. The LFA detection system is based on three types of UCNPs for multiplexed detection. The reader has a dimension of 24.0 cm × 9.4 cm × 5.4 cm (L × W × H) and weight of 0.9 kg. The analyzer based on the custom-designed software of a smartphone (termed as UCNP-LFA analyzer) can get the quantitative analysis results in a real-time manner. We demonstrated the universality of this platform by highly sensitive and quantitative detections of several kinds of targets, including small molecule (ochratoxin A, OTA), heavy metal ion (Hg2+), bacteria (salmonella, SE), nucleic acid (hepatitis B virus, HBV) and protein (growth stimulation expressed gene 2, ST-2). Our developed UCNP-LFA platform holds great promise for applications in disease diagnostics, environmental pollution monitoring and food safety at the point of care.


Assuntos
Imunoensaio/métodos , Nanopartículas/química , Testes Imediatos , Anticorpos/química , Biomarcadores/sangue , DNA/análise , DNA/química , DNA/genética , Érbio/química , Fluoretos/química , Fluoretos/efeitos da radiação , Vírus da Hepatite B/genética , Humanos , Imunoensaio/instrumentação , Proteína 1 Semelhante a Receptor de Interleucina-1/sangue , Proteína 1 Semelhante a Receptor de Interleucina-1/imunologia , Limite de Detecção , Mercúrio/análise , Nanopartículas/efeitos da radiação , Hibridização de Ácido Nucleico , Salmonella/isolamento & purificação , Smartphone , Espectrometria de Fluorescência/métodos , Itérbio/química , Ítrio/química , Ítrio/efeitos da radiação
17.
Dalton Trans ; 48(27): 9962-9973, 2019 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-31074748

RESUMO

Photodynamic and immune therapies are innovative medical strategies against cancer, and their integration with upconversion nanoparticles (UCNPs) can improve the diagnosis and treatment of the disease. The UCNPs convert the deep penetrating near-infrared (NIR) light into higher energy emissions, allowing the imaging and detection of malignant cells and the simultaneous energy transfer for activation of the photosensitizers. In this work, the UCNPs were coated with a photocatalytic TiO2/ZrO2 shell and an increase of oxygen defects (VO) was observed as a result of the partial substitution of Ti4+ by Zr4+ ions in the crystalline lattice of TiO2. Such defects act as trapping states improving charge separation and then reducing the recombination rate of the electron-hole pairs (e-/h+) generated upon resonant energy transfer from the donor (UCNPs) to acceptors (shell). The overall results are the enhancement of both ROS production and the emission band centered at 801 nm which is useful for tracking cells at the deep tissue level. However, an excess of those defects produces deleterious effects on both processes as a result of charge migration. The specificity against HER2 positive breast cancer was provided by bioconjugation with the monoclonal antibody trastuzumab. After administration of the synthesized NaYF4:Yb,Tm@TiO2/ZrO2-trastuzumab theranostic nanocomplex doped with an optimal ZrO2 molar concentration (25%) and subsequent exposure to 975 nm light (0.71 W cm-2) during 5 minutes, HER2-positive SKBr3 breast cancer cells were suppressed with 88% drop of the cell viability, 28% higher than UCNPs decorated with a pure TiO2 shell.


Assuntos
Neoplasias da Mama/patologia , Fluoretos/química , Fotoquimioterapia , Nanomedicina Teranóstica/métodos , Túlio/química , Titânio/química , Itérbio/química , Zircônio/química , Humanos , Células MCF-7 , Nanocompostos/química , Espécies Reativas de Oxigênio/metabolismo , Trastuzumab/química , Trastuzumab/farmacologia
18.
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
19.
Mater Sci Eng C Mater Biol Appl ; 99: 1067-1074, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30889639

RESUMO

Using a facile hydrothermal procedure, hydrophilic NaYF4: Yb3+/Er3+ nanoparticles (NPs) have been prepared as lanthanide-doped upconversion (UC) materials exhibiting different morphologies, crystal phases and luminescence intensity. The upconversion nanoparticles (UCNP) were characterized by means of electron microscopy and spectroscopy, X-ray diffraction (XRD) and photoluminescence analysis. The molar concentration of reactants and volumes of NaF affect the shapes and uniformity of the synthesized NPs. These parameters also have influence on crystal phase and luminescence intensity of the NPs. Adjusting hydrothermal reaction time and dopant concentration also enable the synthesis of NPs with strong UC luminescence. The as-prepared UCNP showed cellular nontoxicity to HeLa cells, and thus they are capable as promising agents for biological imaging.


Assuntos
Monitoramento Ambiental/métodos , Érbio/química , Fluoretos/química , Luminescência , Nanopartículas/química , Temperatura , Água/química , Itérbio/química , Ítrio/química , Morte Celular , Células HeLa , Humanos , Íons , Nanopartículas/ultraestrutura , Tamanho da Partícula , Fluoreto de Sódio/química , Fatores de Tempo
20.
Talanta ; 197: 558-566, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30771976

RESUMO

A selective, simple and environment-friendly type fluorescence sensing platform between upconversion nanoparticles (UCNPs) and melanin-like polymer utilizing the photoinduced electron-transfer (PET) mechanism was developed. The effective fluorescence quenching of UCNPs by melanin-like polymers could detect tyramine and tyrosinase (TYR) activity through the bio-catalysed oxidation of tyramine to the melanin-like polymer products. At optimal conditions, the range of linearity in detection was 0.167-33.3 µΜ for tyramine, and the limit of detection of tyramine was 0.026 µΜ. The linear range of TYR was 0.0033-1 U·mL-1, and the limit of detection of TYR was 0.003 U·mL-1. Furthermore, the strategy could be applied to real sample analysis with satisfactory results.


Assuntos
Corantes Fluorescentes/química , Monofenol Mono-Oxigenase/análise , Tiramina/análise , Érbio/química , Fluoretos/química , Gadolínio/química , Monofenol Mono-Oxigenase/metabolismo , Tamanho da Partícula , Sódio/química , Itérbio/química , Ítrio/química
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