Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
Cell ; 182(3): 713-721.e9, 2020 08 06.
Artículo en Inglés | MEDLINE | ID: mdl-32778225

RESUMEN

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) threatens global public health. The development of a vaccine is urgently needed for the prevention and control of COVID-19. Here, we report the pilot-scale production of an inactivated SARS-CoV-2 vaccine candidate (BBIBP-CorV) that induces high levels of neutralizing antibodies titers in mice, rats, guinea pigs, rabbits, and nonhuman primates (cynomolgus monkeys and rhesus macaques) to provide protection against SARS-CoV-2. Two-dose immunizations using 2 µg/dose of BBIBP-CorV provided highly efficient protection against SARS-CoV-2 intratracheal challenge in rhesus macaques, without detectable antibody-dependent enhancement of infection. In addition, BBIBP-CorV exhibits efficient productivity and good genetic stability for vaccine manufacture. These results support the further evaluation of BBIBP-CorV in a clinical trial.


Asunto(s)
Betacoronavirus/inmunología , Infecciones por Coronavirus/prevención & control , Evaluación Preclínica de Medicamentos/métodos , Pandemias/prevención & control , Neumonía Viral/prevención & control , Vacunas de Productos Inactivados/uso terapéutico , Vacunas Virales/uso terapéutico , Animales , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Betacoronavirus/genética , COVID-19 , Vacunas contra la COVID-19 , Chlorocebus aethiops , Infecciones por Coronavirus/virología , Modelos Animales de Enfermedad , Femenino , Cobayas , Inmunogenicidad Vacunal , Macaca fascicularis , Macaca mulatta , Masculino , Ratones , Ratones Endogámicos BALB C , Filogenia , Neumonía Viral/virología , Conejos , Ratas , Ratas Wistar , SARS-CoV-2 , Vacunas de Productos Inactivados/efectos adversos , Células Vero , Vacunas Virales/efectos adversos
2.
Langmuir ; 39(1): 75-82, 2023 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-36525579

RESUMEN

Tuning the three-dimensional morphology in the active layer is an effective method to improve the performance of bulk heterojunction organic solar cells (OSCs). In this work, an acceptor-donor-acceptor structured small molecule ST10-CN-1 was synthesized and employed as the guest donor to fabricate ternary OSCs based on a PBDB-T:IT-M host binary system. The incorporation of ST10-CN-1 could broaden the active layer's absorption range of solar light thereby leading to a promotional short-circuit current. Moreover, adding an appropriate amount of ST10-CN-1 could effectively regulate the morphology of the active layer in both the lateral direction and vertical stratification. All of these morphological alterations helped to speed up the exciton dissociation, charge transit, and charge collecting processes, which in turn increased the power conversion efficiency. As a result, an excellent PCE of 11.5% for the ternary device based on PBDB-T:IT-M:ST10-CN-1 was obtained. The enhanced PCE was also linked to the formation of an alloylike state between PBDB-T and ST10-CN-1, as evidenced by the fact that the open circuit voltage of ternary OSCs lay between those for PBDB-T:IT-M (0.925 V) and ST10-CN-1:IT-M (1.064 V). This work illustrates that refining the morphology of the active layer by incorporating an appropriate third component is an effective way to further enhance the device's performance.

3.
Plant Cell ; 30(3): 638-651, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29475937

RESUMEN

Nitrogen (N) is a major driving force for crop yield improvement, but application of high levels of N delays flowering, prolonging maturation and thus increasing the risk of yield losses. Therefore, traits that enable utilization of high levels of N without delaying maturation will be highly desirable for crop breeding. Here, we show that OsNRT1.1A (OsNPF6.3), a member of the rice (Oryza sativa) nitrate transporter 1/peptide transporter family, is involved in regulating N utilization and flowering, providing a target to produce high yield and early maturation simultaneously. OsNRT.1A has functionally diverged from previously reported NRT1.1 genes in plants and functions in upregulating the expression of N utilization-related genes not only for nitrate but also for ammonium, as well as flowering-related genes. Relative to the wild type, osnrt1.1a mutants exhibited reduced N utilization and late flowering. By contrast, overexpression of OsNRT1.1A in rice greatly improved N utilization and grain yield, and maturation time was also significantly shortened. These effects were further confirmed in different rice backgrounds and also in Arabidopsis thaliana Our study paves a path for the use of a single gene to dramatically increase yield and shorten maturation time for crops, outcomes that promise to substantially increase world food security.


Asunto(s)
Proteínas de Transporte de Anión/metabolismo , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Proteínas de Transporte de Anión/genética , Regulación de la Expresión Génica de las Plantas/genética , Regulación de la Expresión Génica de las Plantas/fisiología , Mutación/genética , Transportadores de Nitrato , Nitrógeno/metabolismo , Oryza/genética , Proteínas de Plantas/genética
4.
BMC Plant Biol ; 20(1): 330, 2020 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-32660424

RESUMEN

BACKGROUND: Phosphorus deficiency is a major limiting factors for affecting crop production globally. To understand the genetic variation of phosphorus-deficiency-tolerance, a total of 15 seedling traits were evaluated among 707 Chinese wheat landraces under application of phosphorus (AP) and non-application of phosphorus (NP). A total of 18,594 single-nucleotide polymorphisms and 38,678 diversity arrays technology sequencing markers were used to detect marker-trait associations under AP and NP. RESULTS: Top ten genotypes with extremely tolerance and bottommost ten genotypes with extremely sensitivity were selected from 707 Chinese wheat landraces for future breeding and genetic analysis. A total of 55 significant markers (81 marker-trait associations) for 13 traits by both CMLM and SUPER method. These were distributed on chromosomes 1A, 1B, 2A, 2B, 2D, 3A, 4B, 5A, 5B, 6A, 6B, 6D, 7A and 7B. Considering the linkage disequilibrium decay distance, 25 and 12 quantitative trait loci (QTL) were detected under AP and NP, respectively (9 QTL were specific to NP). CONCLUSIONS: The extremely tolerant landraces could be used for breeding phosphorus-deficiency-tolerant cultivars. The QTL could be useful in wheat breeding through marker-assisted selection. Our findings provide new insight into the genetic analysis of P-deficiency-tolerance, and will be helpful for breeding P-deficiency-tolerant cultivars.


Asunto(s)
Variación Genética , Fósforo/deficiencia , Polimorfismo de Nucleótido Simple/genética , Sitios de Carácter Cuantitativo/genética , Triticum/genética , Estudios de Asociación Genética , Genotipo , Desequilibrio de Ligamiento , Fenotipo , Fitomejoramiento , Plantones/genética , Plantones/fisiología , Estrés Fisiológico , Triticum/fisiología
5.
Plant Biotechnol J ; 17(6): 1058-1068, 2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30466149

RESUMEN

Selenium (Se) is an essential trace element for humans and other animals, yet approximately one billion people worldwide suffer from Se deficiency. Rice is a staple food for over half of the world's population that is a major dietary source of Se. In paddy soils, rice roots mainly take up selenite. Se speciation analysis indicated that most of the selenite absorbed by rice is predominantly transformed into selenomethinone (SeMet) and retained in roots. However, the mechanism by which SeMet is transported in plants remains largely unknown. In this study, SeMet uptake was found to be an energy-dependent symport process involving H+ transport, with neutral amino acids strongly inhibiting SeMet uptake. We further revealed that NRT1.1B, a member of rice peptide transporter (PTR) family which plays an important role in nitrate uptake and transport in rice, displays SeMet transport activity in yeast and Xenopus oocyte. The uptake rate of SeMet in the roots and its accumulation rate in the shoots of nrt1.1b mutant were significantly repressed. Conversely, the overexpression of NRT1.1B in rice significantly promoted SeMet translocation from roots to shoots, resulting in increased Se concentrations in shoots and rice grains. With vascular-specific expression of NRT1.1B, the grain Se concentration was 1.83-fold higher than that of wild type. These results strongly demonstrate that NRT1.1B holds great potential for the improvement of Se concentrations in grains by facilitating SeMet translocation, and the findings provide novel insight into breeding of Se-enriched rice varieties.


Asunto(s)
Proteínas de Transporte de Anión , Oryza , Proteínas de Plantas , Selenio , Proteínas de Transporte de Anión/genética , Proteínas de Transporte de Anión/metabolismo , Transporte Biológico/genética , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raíces de Plantas/metabolismo , Semillas/genética , Semillas/metabolismo , Selenio/metabolismo , Suelo/química
6.
Genome ; 61(3): 209-215, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29373804

RESUMEN

Deficiency of available phosphorus (P) in soil limits wheat production and creates a need to develop P-deficiency-tolerant cultivars. Plant roots, important organs for absorbing nutrients and synthesizing growth regulators, are good candidates for P-efficiency screening. In this study, we evaluated five root traits under hydroponic culture conditions either with (AP) or without (NP) applied P in a recombinant inbred line population (H461/CM107) of Triticum aestivum L. at the seedling stage. Four significant quantitative trait loci (QTL) were detected, on chromosomes 1D, 2D, 3D, and 7D in NP-treated plants, explaining up to 13.0%, 11.0%, 14.4%, and 12.8% of the phenotypic variance, respectively. Among these QTL, Qrt.sicau-3D and Qrt.sicau-7D showed pleiotropic and additive effects. All QTL were found to be novel. The diversity array technology markers flanking the QTL were converted to simple sequence repeat markers that can be deployed in future genetic studies of P deficiency. These QTL lead to an increase in root biomass and respond to P-deficiency stress; these characteristics are crucial to improve root traits for breeding or further investigation of the gene(s) involved in P-deficiency tolerance.


Asunto(s)
Fósforo/deficiencia , Raíces de Plantas/genética , Sitios de Carácter Cuantitativo , Triticum/genética , Cromosomas de las Plantas/genética , Pleiotropía Genética , Repeticiones de Microsatélite , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Plantones/genética , Plantones/crecimiento & desarrollo , Plantones/metabolismo , Triticum/crecimiento & desarrollo , Triticum/metabolismo
7.
Plant J ; 75(4): 642-55, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23647236

RESUMEN

The ICK/KRP cyclin-dependent kinase (CDK) inhibitors are important plant cell cycle factors sharing only limited similarity with the metazoan CIP/KIP family of CDK inhibitors. Little is known about the specific functions of different ICK/KRP genes in planta. In this study, we created double and multiple mutants from five single Arabidopsis ICK/KRP T-DNA mutants, and used a set of 20 lines for the functional investigation of the important gene family. There were gradual increases in CDK activity from single to multiple mutants, indicating that ICK/KRPs act as CDK inhibitors under normal physiological conditions in plants. Whereas lower-order mutants showed no morphological phenotypes, the ick1 ick2 ick6 ick7 and ick1 ick2 ick5 ick6 ick7 mutants had a slightly altered leaf shape. The quintuple mutant had larger cotyledons, leaves, petals and seeds than the wild-type control. At the cellular level, the ICK/KRP mutants had more but smaller cells in all the organs examined. These phenotypic effects became more apparent as more ICK/KRPs were downregulated, suggesting that to a large extent ICK/KRPs function in plants redundantly in a dosage-dependent manner. Analyses also revealed increased expression of E2F-dependent genes, and elevated RBR1 as well as an increased level of phospho-RBB1 protein in the quintuple mutant. Thus, downregulation of multiple ICK/KRP genes increases CDK activity, upregulates the E2F pathway and stimulates cell proliferation, resulting in increased cell numbers, and larger organs and seeds.


Asunto(s)
Arabidopsis/genética , Proteínas Inhibidoras de las Quinasas Dependientes de la Ciclina/genética , Quinasas Ciclina-Dependientes/metabolismo , Regulación de la Expresión Génica de las Plantas , Arabidopsis/citología , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Recuento de Células , Proliferación Celular , Tamaño de la Célula , Cotiledón/citología , Cotiledón/genética , Cotiledón/crecimiento & desarrollo , Cotiledón/metabolismo , Proteínas Inhibidoras de las Quinasas Dependientes de la Ciclina/metabolismo , Quinasas Ciclina-Dependientes/genética , Regulación hacia Abajo , Flores/citología , Flores/genética , Flores/crecimiento & desarrollo , Flores/metabolismo , Modelos Biológicos , Mutagénesis Insercional , Fenotipo , Hojas de la Planta/citología , Hojas de la Planta/genética , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/metabolismo , Plantas Modificadas Genéticamente , Semillas/citología , Semillas/genética , Semillas/crecimiento & desarrollo , Semillas/metabolismo
8.
ChemistryOpen ; 13(5): e202300178, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38214441

RESUMEN

Efficient energy storage systems are crucial for the optimal utilization of renewable energy. Sodium-ion batteries (SIBs) are considered potential substitutes for next-generation low-cost energy storage systems due to the low cost and abundance of sodium resources. However, the industrialization of SIBs faces a great challenge in terms of the anode. Hard carbon could be a promising anode material due to its high capacity and low cost which originates from biomass. This study used pre-treatment and template carbonization methods to extract a hard carbon material from a large amount of discarded biomass in bamboo powder waste. This material has a good initial Coulombic efficiency of 78.6 % and good cycling stability when applied to sodium ion batteries.Typically, the optimal hard carbon material is used as the anode to prepare sodium ion battery prototypes to demonstrate their potential applications. The anode exhibited excellent sodium storage performance with a reversible capacity of 303 mAh ⋅ g-1 at 1 C rate and good cycling performance, retaining 92.0 % of its capacity after 100 cycles. These results demonstrate that BPPHC is a promising candidate for anode material in sodium-ion batteries. This work suggests that bamboo powder could be a low-cost anode material for SIBs.

9.
Insects ; 12(5)2021 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-33946159

RESUMEN

Species identification of Aphytis on the basis of adult morphology is extremely difficult, especially in the A. lingnanensis group, with several cryptic species. Pupal pigmentation could be used as one of the taxonomic characters for Aphytis species, and in some instances, pupal pigmentation actually provided the first clue to the distinctness of cryptic Aphytis species. The present study investigated the full-grown larvae or younger pupae of Aphytis species, and pupal pigmentation and pupal development were observed and photographed. Four characteristic pigmentation patterns of Aphytis pupae were summarized including: entirely yellow, partly dark brown, entirely or predominantly black, and partly black. The species in the chilensis and mytilaspidis groups, and some unassigned species, generally have entirely, or predominantly and or partly black pupae. The species in the chrysomphali, funicularis, and proclia groups generally have the pupae entirely yellow. The species of the lingnanensis group have the pupae both entirely yellow, e.g., A. fisheri, and partly dark brown pupae, e.g., A. lingnanensis, A. holoxanthus and A. melinus. The pupae of Aphytis species in this study had a developmental duration of about 5-8 days at 27 ± 1 °C, 70 ± 5% RH and a photoperiod of 10L: 14D. It was found that the pupal skin was always melanized at the beginning stage, generally in the first day, among the pigmented pupae of Aphytis species. As development continued, the pigmentation became darker and the eye colour changed from pale red/brown to green. No significant intra-specific variation in pupal colour pattern was detected despite relatively high numbers of specimens examined, many from multiple, and different, origins. Overall, our study indicates that pupal pigmentation could be more helpful in species identification of Aphytis.

10.
J Tradit Chin Med ; 29(3): 205-8, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19894386

RESUMEN

Prof. CAI Gan is an academic leader in TCM treatment of the spleen and stomach disease. He insisted that liver depression, spleen deficiency and poor nourishment of the intestines are the core of pathogenesis for chronic constipation. Therefore he often treats the disease by strengthening the spleen, relieving the depressed liver, nourishing yin and moistening the intestines. Meanwhile he attaches great importance to syndrome differentiation and comprehensive regulation and treatment. As a result, good therapeutic effects are often achieved. The authors summarized his ways for treating chronic constipation with the following 10 methods, which are introduced below.


Asunto(s)
Estreñimiento/terapia , Medicina Tradicional China/métodos , Qi , Circulación Sanguínea/efectos de los fármacos , Enfermedad Crónica , Estreñimiento/fisiopatología , Medicamentos Herbarios Chinos/uso terapéutico , Humanos , Intestinos/efectos de los fármacos , Intestinos/fisiopatología , Riñón/efectos de los fármacos , Riñón/fisiopatología , Hígado/efectos de los fármacos , Hígado/fisiopatología , Pulmón/efectos de los fármacos , Pulmón/fisiopatología , Guías de Práctica Clínica como Asunto , Bazo/efectos de los fármacos , Bazo/fisiopatología
11.
Front Plant Sci ; 10: 1090, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31572412

RESUMEN

The Arabidopsis cyclic nucleotide-gated channel (CNGC) family consists of 20 members, which have been reported to participate in various physiological processes, such as pathogen defense, development, and thermotolerance. Although CNGC11 and CNGC12 have been identified a decade ago and their role in programmed cell death is well studied, their precise channel regulation has not been studied electrophysiologically. Here, we determined the channel activities of CNGC11 and CNGC12 utilizing the two-electrode voltage-clamp technique in the Xenopus laevis oocyte heterologous expression system. Our results suggest that CNGC12 but not CNGC11 functions as an active calcium channel. Furthermore, the cyclic nucleotide monophosphates (cNMPs) did not affect the activities of CNGC11 nor CNGC12 in Xenopus oocytes. Interestingly, while the activity of CNGC11 was not affected by co-expression with calmodulin (CaM), the activity of CNGC12 was significantly enhanced when CaM1 was co-expressed in oocytes. This study reveals that the channel activities and the mechanisms of regulation by CaM are different between CNGC11 and CNGC12.

12.
Front Plant Sci ; 7: 331, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27047512

RESUMEN

Association mapping is a powerful approach for exploring the molecular genetic basis of complex quantitative traits. An alfalfa (Medicago sativa) association panel comprised of 336 genotypes from 75 alfalfa accessions represented by four to eight genotypes for each accession. Each genotype was genotyped using 85 simple sequence repeat (SSR) markers and phenotyped for five fiber-related traits in four different environments. A model-based structure analysis was used to group all genotypes into two groups. Most of the genotypes have a low relative kinship (<0.3), suggesting population stratification not be an issue for association analysis. Generally, the Q + K model exhibited the best performance to eliminate the false associated positives. In total, 124 marker-trait associations were predicted (p < 0.005). Among these, eight associations were predicted in two environments repeatedly and 20 markers were predicted to be associated with multiple traits. These trait-associated markers will greatly help marker-assisted breeding programs to improve fiber-related quality traits in alfalfa.

13.
PLoS One ; 10(4): e0124592, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25901573

RESUMEN

Information on genetic diversity and population structure of a tetraploid alfalfa collection might be valuable in effective use of the genetic resources. A set of 336 worldwide genotypes of tetraploid alfalfa (Medicago sativa subsp. sativa L.) was genotyped using 85 genome-wide distributed SSR markers to reveal the genetic diversity and population structure in the alfalfa. Genetic diversity analysis identified a total of 1056 alleles across 85 marker loci. The average expected heterozygosity and polymorphism information content values were 0.677 and 0.638, respectively, showing high levels of genetic diversity in the cultivated tetraploid alfalfa germplasm. Comparison of genetic characteristics across chromosomes indicated regions of chromosomes 2 and 3 had the highest genetic diversity. A higher genetic diversity was detected in alfalfa landraces than that of wild materials and cultivars. Two populations were identified by the model-based population structure, principal coordinate and neighbor-joining analyses, corresponding to China and other parts of the world. However, lack of strictly correlation between clustering and geographic origins suggested extensive germplasm exchanges of alfalfa germplasm across diverse geographic regions. The quantitative analysis of the genetic diversity and population structure in this study could be useful for genetic and genomic analysis and utilization of the genetic variation in alfalfa breeding.


Asunto(s)
Variación Genética , Medicago sativa/crecimiento & desarrollo , Medicago sativa/genética , Repeticiones de Microsatélite/genética , Semillas/genética , Tetraploidía , Alelos , Cromosomas de las Plantas/genética , Análisis por Conglomerados , Genética de Población , Genotipo , Filogenia , Análisis de Componente Principal
14.
Nanoscale ; 4(8): 2606-12, 2012 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-22422312

RESUMEN

ZnO replicas with photonic structures were fabricated from Papilio paris butterfly wing scales and their tunable optical properties were studied. Through modification of the fabrication method, the reticular porous network structure was successfully replicated from dark black (DB) wing scales. The DB wing scale replicas exhibit a photonic band gap (PBG) in the visible region, which overlaps with the visible emission range of ZnO. Both DB and GB (greenish-blue) wing scale replicas can work as one-dimensional diffraction gratings in optical diffraction experiments, whose spot distances can be tuned by different periodic sizes of butterfly wing structure. Moreover, the ZnO DB wing scale replicas exhibit improved photoluminescence (PL) spectra with reduced visible emission and enhanced UV emission, which can both be attributed to the existence of a PBG produced by the reticular porous network structure in DB wing scales. These results can be very helpful in the research of applications of ZnO materials in UV lasing and optical diffraction devices.

15.
ACS Appl Mater Interfaces ; 3(6): 2057-62, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21634372

RESUMEN

Bundlelike VO(2)(B) nanostructures were synthesized via a hydrothermal method, and VO(2)(M(1)/R) nanobundles were obtained after a heat-treatment process. Structural characterization shows that these nanobundles are self-assembled by VO(2) nanowires, and VO(2)(M(1)/R) nanobundles have better crystallinity. Temperature-dependent field-emission (FE) measurement indicates that FE properties of these two phases of nanobundles can both be improved by increasing the ambient temperature. Moreover, for the VO(2)(M(1)/R) nanobundles, their FE properties are also strongly dependent on the temperature-induced metal-insulator transitions process. Compared with poor FE properties found in the insulating phase, FE properties were significantly improved by increasing the temperature, and about a three-orders-of-magnitude increasing of the emission current density has been observed at a fixed field of 6 V/µm. Work function measurement and density-functional theory calculations indicated that the decrease of work function with temperature is the main reason that caused the improvement of FE properties. These characteristics make VO(2)(M(1)/R) a candidate material for application of new type of temperature-controlled field emitters, whose emission density can be adjusted by ambient temperature.

16.
Nanoscale ; 3(12): 5000-6, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22031229

RESUMEN

A ZnO photonic amorphous diamond nanostructure was successfully synthesised using a feather barb of the Rosy-Faced Lovebird as supporting template via a facile sol-gel process. Different from ordered structures, an isotropic PBG around 500 nm was evidenced from reflectance spectra and an optical metallurgical microscopy image, which overlaps with the visible emission peak of ZnO. As a result, the inhibition of visible emission inside the PBG and the enhancement of UV emission at the PBG edges have both been observed, which is independent from the incident angle. Moreover, the rapid thermal annealing can also help improve the crystallinity of ZnO and raise the UV/visible emission ratio without affecting the structure. These results can be very useful for the study of the modification of the optical emission properties of ZnO and other semiconductor materials as well as research on ZnO random lasing.


Asunto(s)
Plumas/ultraestructura , Luminiscencia , Nanodiamantes/química , Nanodiamantes/ultraestructura , Óxido de Zinc/química , Animales , Loros/anatomía & histología
17.
Nanoscale ; 3(5): 2315-23, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21503355

RESUMEN

A facile method of synthesizing 60 nm magnetic-fluorescent core-shell bifunctional nanocomposites with the ability to label cells is presented. Hydrophobic trioctylphosphine oxide (TOPO)-capped CdSe@ZnS quantum dots (QDs) were assembled on polyethyleneimine (PEI)-coated Fe(3)O(4) nanoparticles (MNP). Polyethyleneimine was utilized for the realization of multifunction, including attaching 4 nm TOPO capped CdSe@ZnS quantum dots onto magnetite particles, altering the surface properties of quantum dots from hydrophobic to hydrophilic as well as preventing the formation of large aggregates. Results show that these water-soluble hybrid nanocomposites exhibit good colloidal stability and retain good magnetic and fluorescent properties. Because TOPO-capped QDs are assembled instead of their water-soluble equivalents, the nanocomposites are still highly luminescent with no shift in the PL peak position and present long-term fluorescence stability. Moreover, TAT peptide (GRKKRRQRRRPQ) functionalized hybrid nanoparticles were also studied due to their combined magnetic enrichment and optical detection for cell separation and rapid cell labelling. A cell viability assay revealed good biocompatibility of these hybrid nanoparticles. The potential application of the new magnetic-fluorescent nanocomposites in biological and medicine is demonstrated.


Asunto(s)
Células Cultivadas/citología , Colorantes Fluorescentes/síntesis química , Microscopía Fluorescente/métodos , Nanoestructuras/química , Animales , Humanos , Magnetismo , Ensayo de Materiales , Coloración y Etiquetado/métodos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA