Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 76
Filtrar
1.
Biomaterials ; 270: 120682, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33529961

RESUMO

Smart nano-micro platforms have been extensively applied for diverse biomedical applications, mostly focusing on cancer therapy. In comparison with conventional nanotechnology, the smart nano-micro matrix can exhibit specific response to exogenous or endogenous triggers, and thus can achieve multiple functions e.g. site-specific drug delivery, bio-imaging and detection of bio-molecules. These intriguing techniques have expanded into ophthalmology in recent years, yet few works have been summarized in this field. In this work, we provide the state-of-the-art of diverse nano-micro platforms based on both the conventional materials (e.g. natural or synthetic polymers, lipid nanomaterials, metal and metal oxide nanoparticles) and emerging nanomaterials (e.g. up-conversion nanoparticles, quantum dots and carbon materials) in ophthalmology, with some smart nano/micro platformers highlighted. The common ocular diseases studied in the field of nano-micro systems are firstly introduced, and their therapeutic method and the related drawback in clinic treatment are presented. The recent progress of different materials for diverse ocular applications is then demonstrated, with the representative nano- and micro-systems highlighted in detail. At last, an in-depth discussion on the clinical translation challenges faced in this field and the future direction are provided. This review would allow the researchers to design more smart nanomedicines in a more rational manner for specific ophthalmology applications.

2.
Immun Inflamm Dis ; 2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33503296

RESUMO

BACKGROUND: Glioma is the most common intracranial tumor. The inflammatory response actively participates in the malignancy of gliomas. There is still limited knowledge about the biological function of immune-related genes (IRGs) and their potential involvement in the malignancy of gliomas. METHODS: We screened differentially expressed and survival-associated IRGs, and explored their potential molecular characteristics. Then we developed a prognostic index derived from seven hub IRGs. A prognostic nomogram was built to indicate the prognostic value of the prognostic index and seven IRGs. We characterized the immune infiltration landscape to analyze tumor-immune interactions. The real-time quantitative polymerase chain reaction assay was performed to validate bioinformatics results. RESULTS: The differentially expressed IRGs are involved in cell chemotaxis, cytokine activity, and the chemokine-mediated signaling pathway. The prognostic index derived from seven IRGs had clinical prognostic value in glioma, and positively correlated with the malignant clinicopathological characteristics. A nomogram further indicated that the prognostic index and seven hub IRGs had clinical prognostic value for gliomas. We revealed that the prognostic index could reflect the state of the glioma immune microenvironment. CONCLUSION: This study demonstrates the importance of an IRG-based prognostic index as a potential biomarker for predicting malignancy in gliomas.

3.
Artigo em Inglês | MEDLINE | ID: mdl-33162042

RESUMO

To improve the photocatalytic activity of TiO2 NBs under irradiation of solar light, an immobilized Z-scheme composite photocatalyst CdS/Au/TiO2 NBs has been constructed. For the unique architectures, the TiO2 NBs provide more absorption and reaction sites, the CdS nanoparticles enhance overall light harvesting, and Au acts as the electron transfer mediator, promoting the interfacial charge transfer and efficient separation of electrons and holes. The morphology, elements, crystal structure, optical and photoelectrochemical properties, and photocatalytic activity of CdS/Au/TiO2 NBs were characterized. Results showed that CdS/Au/TiO2 NBs possesses higher photocatalytic activity toward the degradation of antibiotic norfloxacin under irradiation of simulated sunlight, which is attributed to the synergetic interaction of increased light absorption and separation of photogenerated electrons and holes. Besides, the degradation of norfloxacin was promoted by HCO3-, but inhibited by NO3- and Cl-. The radicals trapping experiments proved that superoxide radicals (O2-) was the dominating active species during the photocatalysis process. The photocatalytic degradation products of norfloxacin was analyzed, and nine intermediates were identified. Moreover, the photocatalytic degradation mechanism and photostability of CdS/Au/TiO2 NBs were analyzed in detail. The matched energy levels and unique ternary Z-scheme design are the key for improved photocatalytic activity. The deactivation of CdS/Au/TiO2 NBs after recycles mainly due to the release of CdS by photocorrosion and the loss of deposited Au.

4.
Plant Biotechnol J ; 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-33236499

RESUMO

Foods high in amylose content and resistant starch (RS) offer great potential to improve human health and lower the risk of serious noninfectious diseases. Common wheat (Triticum aestivum L.) is a major staple food crop globally. However, the RS contents in the grains of modern wheat varieties are low. Here, we report the generation of high-amylose wheat through targeted mutagenesis of TaSBEIIa in a modern winter wheat cv Zhengmai 7698 (ZM) and a spring wheat cv Bobwhite by CRISPR/Cas9, respectively. We generated a series of transgene-free mutant lines either with partial or triple null TasbeIIa alleles in ZM and Bobwhite, respectively. Analyses of starch composition, structure and properties revealed that the effects of partial or triple null alleles were dosage dependent with triple null lines demonstrated more profound impacts on starch composition, fine structures of amylopectin, and physiochemical and nutritional properties. The flours of triple null lines possessed significantly increased amylose, RS, protein and soluble pentosan contents which benefit human health. Baking quality analyses indicated that the high-amylose flours may be used as additives or for making cookies. Collectively, we successfully modified the starch composition, structure and properties through targeted mutagenesis of TaSBEIIa by CRISPR/Cas9 in both winter and spring wheat varieties, and generated transgene-free high-amylose wheat. Our finding provides deep insights on the role of TaSBEIIa in determining starch composition, structure, properties and end-use quality in different genetic backgrounds, and improving RS content with multiple breeding and end-use applications in cereal crop species through genome editing for health benefits.

5.
Anal Chem ; 92(22): 15179-15186, 2020 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-33112598

RESUMO

Engineering a functional nanoplatform that integrates dynamic monitoring of endogenous biomarkers and a stimuli-activated therapeutic mode is promising for early diagnosis and treatment of cancers. In this study, we developed an intelligent DNA nanohydrogel with specific targeting capability that can be stimuli-activated for both in vitro telomerase detection and in vivo telomerase-triggered gene therapy. The DNA nanohydrogel was formed simply by the self-assembly of two Y-shaped DNA units and a double-stranded DNA linker labeled with fluorophores and loaded with therapeutic siRNA. When intracellular telomerase was overexpressed, the DNA nanohydrogel collapsed owing to the prolongation of the telomeric primer at the terminal sequence of one of the Y-shaped DNA units. As a result, the quenched fluorescence due to fluorescence resonance energy transfer (FRET) of the DNA nanohydrogel recovered and the trapped siRNA was released, enabling the accurate detection and imaging of intracellular telomerase activity as well as effective gene therapy of tumors. Benefiting from the great biocompatibility, specificity, and stimuli-responsive property, the developed DNA nanoplatform provides a new opportunity for precise cancer diagnosis and treatment as well as other biological applications.

6.
J Immunol ; 205(8): 2137-2145, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32929042

RESUMO

IgG subclass diversification is common in placental mammals. It has been well documented in humans and mice that different IgG subclasses, with diversified functions, synergistically regulate humoral immunity. However, our knowledge on the genomic and functional diversification of IgG subclasses in the pig, a mammalian species with high agricultural and biomedical importance, is incomplete. Using bacterial artificial chromosome sequencing and newly assembled genomes generated by the PacBio sequencing approach, we characterized and mapped the IgH C region gene locus in three indigenous Chinese breeds (Erhualian, Xiang, and Luchuan) and compared them to that of Duroc. Our data revealed that IGHG genes in Chinese pigs differ from the Duroc, whereas the IGHM, IGHD, IGHA, and IGHE genes were all single copy and highly conserved in the pig breeds examined. Most striking were differences in numbers of IGHG genes: there are seven genes in Erhualian pigs, six in the Duroc, but only five in Xiang pigs. Phylogenetic analysis suggested that all reported porcine IGHG genes could be classified into nine subclasses: IGHG1, IGHG2a, IGHG2b, IGHG2c, IGHG3, IGHG4, IGHG5a, IGHG5b, and IGHG5c. Using sequence information, we developed a mouse mAb specific for IgG3. This study offers a starting point to investigate the structure-function relationship of IgG subclasses in pigs.

7.
Opt Express ; 28(17): 25606-25617, 2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-32907076

RESUMO

Alumina particles experience phase transition as an undercooling process along the plume, during which the liquid alumina clusters transform into multiphase, and then into α phase. The phase transformation model was built by an improved diffusion limited aggregation (DLA) algorithm with monomers of stratified structure. The effects of phase transformation on the ultraviolet optical characteristics of alumina clusters were studied using the superposition T-matrix method (STMM). We found that the alumina clusters in phase transition had completely different optical properties compared with the fixed phase ones. Forward scattering, absorption efficiency and asymmetry parameter gradually decreased, whereas backward scattering, scattering efficiency, and single-scattering albedo gradually increased during the phase transformation process. Besides, multiphase alumina clusters were compared with the other two equivalent models, including the sphere model approximated by equivalent volume sphere (EVS) and the equivalent surface sphere (ESS) approaches and single-phase cluster model approximated by Maxwell-Garnett (MG) and Bruggeman (BR) approaches. Generally speaking, the optical properties of the single-phase cluster approximated by MG and BR approaches were relatively close to those of the real multiphase alumina cluster. Whereas the spheres approximated by EVS and ESS had great deviations, especially when the number of monomers in the cluster was 20, the relative error of scattering efficiency calculated by ESS was up to 52%. Therefore, approximate approaches for multiphase clusters should be chosen cautiously. Our results give further the understanding of the optical properties of alumina clusters. As the phase states are usually closely related to the plume radiation and burning process, these kinds of researches will be helpful to aircraft detection, identification, and other related fields.

8.
Mol Plant ; 13(6): 811-813, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32353627
9.
Front Chem ; 8: 409, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32457879

RESUMO

Li metal batteries have been considered as the most promising batteries with high energy density for cutting-edge electronic devices such as electric vehicles, autonomous aircrafts, and smart grids. However, Li metal anode faces the issues of safety and capacity deterioration, which are closely related to Li dendrite growth. In this paper, we review the main strategies to improve the performance of Li metal anode. Due to Li dendrite's catastrophic influence, suppression of Li dendrite growth is prerequisite for each strategy. Apart from Li dendrite, interfacial resistance between electrolyte and electrode, ionic conductivity of electrolytes, mechanical strength, and volume fluctuation of Li metal anode are also discussed in these strategies. We outline these strategies based on the classifications of constructing solid electrolyte interphase, engineering of solid-state electrolyte and adopting matrix for Li metal anode. Each strategy is illustrated and discussed in detail by exemplification. For better understanding, some important theories related to Li metal anode have been also introduced. Finally, the outlooks for future research of Li metal anode are presented.

11.
Front Chem ; 8: 150, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32185164

RESUMO

In this study, two kinds of composites with the structure of graphene oxide (GO) sheets wrapped magnetic nanoparticles were investigated on their regeneration. The composites have a similar core-shell structure, but the interactions between the core and shell are quite different, which are electrostatic and covalent. They were characterized by scanning/transmission electron microscopy, power X-ray diffraction, and vibrating sample magnetometer analysis. Their morphologies and structures of the samples had been revealed using methylene blue and Pb(II) as adsorbates during regeneration. The results showed that the composites with covalent bonding interaction could maintain a stable core-shell structure and present a good regeneration performance for adsorption-desorption of methylene blue and Pb(II). The composites with electrostatic interaction could approximately preserve its core-shell structure and could be recyclable for adsorption-desorption of methylene blue, however, they would disintegrate its core-shell structure during adsorption/desorption of Pb(II), thus greatly decreasing their regeneration performance. The regeneration mechanisms of the composites were analyzed, which could provide a useful theoretical guide to design the GO sheets wrapped magnetic nanoparticles composites.

12.
Chem Soc Rev ; 49(5): 1545-1568, 2020 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-32040109

RESUMO

Cell surface receptors are important proteins that mediate communication between the cells and their outside environment, and also play essential roles in the control of a wide variety of biological processes, such as cell cycle, proliferation, communication, migration and apoptosis. Receptor oligomerization is an essential signal transduction mechanism that cell surface receptors use to transmit extracellular signals into the internal cytosol cellular machinery. Therefore, regulating receptor oligomerization provides an opportunity to customize cellular signaling and to direct cellular behavior in a user-defined manner. Some techniques have been developed for receptor oligomerization regulation, such as chemically induced dimerization (CID) and optogenetics, which involve traditional genetic engineering. However, the process of genetic manipulation is time-consuming, unpredictable and inefficient. Thus, development of nongenetic strategies for precisely regulating receptor oligomerization remains a desirable goal. Recently, along with the utilization of DNA, protein, small molecules and stimuli-responsive materials-based nongenetic engineering strategies, various receptor oligomerization and multiple cellular behaviors could be regulated, including migration, proliferation, apoptosis, differentiation and immune responses, etc. In this review, we aim to systematically introduce advances in the development of nongenetic engineering strategies for regulating receptor oligomerization, and provide insights into the existing challenges and future perspectives of this field.


Assuntos
Engenharia de Proteínas , Receptores de Superfície Celular/metabolismo , Animais , Sobrevivência Celular , Humanos , Células-Tronco/citologia , Células-Tronco/metabolismo
13.
Angew Chem Int Ed Engl ; 58(50): 18186-18190, 2019 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-31595614

RESUMO

Programming cells to sense multiple inputs and activate cellular signal transduction cascades is of great interest. Although this goal has been achieved through the engineering of genetic circuits using synthetic biology tools, a nongenetic and generic approach remains highly demanded. Herein, we present an aptamer-controlled logic receptor assembly for modulating cellular signal transduction. Aptamers were engineered as "robotic arms" to capture target receptors (c-Met and CD71) and a DNA logic assembly functioned as a computer processor to handle multiple inputs. As a result, the DNA assembly brings c-Met and CD71 into close proximity, thus interfering with the ligand-receptor interactions of c-Met and inhibiting its functions. Using this principle, a set of logic gates was created that respond to DNA strands or light irradiation, modulating the c-Met/HGF signal pathways. This simple modular design provides a robust chemical tool for modulating cellular signal transduction.


Assuntos
Antígenos CD/metabolismo , Aptâmeros de Nucleotídeos/metabolismo , Proteínas Proto-Oncogênicas c-met/metabolismo , Receptores da Transferrina/metabolismo , Transdução de Sinais/fisiologia , Aptâmeros de Nucleotídeos/química , Carbocianinas/química , Linhagem Celular , Transferência Ressonante de Energia de Fluorescência , Fator de Crescimento de Hepatócito/farmacologia , Humanos , Microscopia Confocal , Sondas Moleculares/química , Transdução de Sinais/efeitos dos fármacos
14.
ACS Appl Mater Interfaces ; 11(40): 36970-36984, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31487152

RESUMO

Carbon quantum dots (CQDs) as novel types of emerging materials have aroused tremendous attention in recent years. Herein, we report for the first time a new application of 3D CQD-based composite aerogels as excellent electrode materials for alkaline aqueous batteries. The scalable graphitic CQDs are prepared with high yields (>40%) and further utilized to fabricate the novel nitrogen-doped CQDs/reduced graphene oxide/porous Fe2O3 (N-CQDs/rGO/Fe2O3) composite aerogels with different contents of Fe2O3. Benefiting from the unique 3D network composite aerogel structure with a high surface area and hierarchical porous structure as well as the synergistic effect of high-capacity Fe2O3 and highly conductive and stable N-CQDs/rGO, the composite aerogels achieve enhanced electrochemical properties with ultrahigh specific capacity, admirable rate property, and superior cycling performance. Furthermore, the N-CQDs/rGO/Fe2O3-1 electrode (Fe2O3, 34.9 wt %) exhibits the best rate capability (72.1, 58.9, and 46.2% capacity retention at 5, 50, and 100 A g-1, respectively) and cycle performance (80.4% capacity retention at 3 A g-1 over 5000 cycles), while the N-CQDs/rGO/Fe2O3-3 electrode (Fe2O3, 62.3 wt %) displays the highest specific capacity (274.1 mA h g-1 at 1 A g-1). The current research provides a valuable guidance for developing high-performance 3D CQD-based composite aerogels for application in energy storage systems.

15.
Chem Commun (Camb) ; 55(82): 12320-12323, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31556438

RESUMO

Crystalline RuSe2 nanoparticles were prepared by a facile hydrothermal approach followed by thermal treatment, and utilized as a pseudocapacitive electrode material for supercapacitors for the first time, which exhibited a specific capacitance of 100.8 F g-1 at 0.2 A g-1 with good rate performance and superior cycle stability.

16.
J Am Chem Soc ; 141(32): 12673-12681, 2019 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-31381313

RESUMO

Cell surface receptors play a critical role in modulating intracellular signal transduction, making them important drug targets. However, it remains challenging to develop a selective and efficient strategy for regulating receptor function. Herein, we develop a strategy, called bispecific aptamer induced artificial protein-pairing, to selectively regulate receptor function. In this strategy, bispecific aptamer probes act as molecular mediators to bind to both a target receptor protein and a paired protein, which brings the two proteins into close proximity on the living cell membrane. Importantly, the paired proteins work not only as a cancer biomarker for enhancing cell selectivity but also as a blocking assistant to inhibit target receptor function via strong steric hindrance effect. Compared with single-aptamer-mediated regulation, the proposed bispecific aptamer probes afford substantial improvement in selective and efficient regulation of receptor function and downstream signaling pathways. This work offers a versatile methodology to design molecular mediators that can modulate receptor function, thereby providing a new way for developing novel therapeutic drugs.


Assuntos
Aptâmeros de Nucleotídeos/metabolismo , Fator de Crescimento de Hepatócito/metabolismo , Proteínas Proto-Oncogênicas c-met/metabolismo , Receptores da Transferrina/metabolismo , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Movimento Celular/efeitos dos fármacos , Difusão , Humanos , Simulação de Dinâmica Molecular , Proteínas Proto-Oncogênicas c-met/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos
18.
Nat Biotechnol ; 37(4): 445-450, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30886437

RESUMO

One of the main obstacles to gene replacement in plants is efficient delivery of a donor repair template (DRT) into the nucleus for homology-directed DNA repair (HDR) of double-stranded DNA breaks. Production of RNA templates in vivo for transcript-templated HDR (TT-HDR) could overcome this problem, but primary transcripts are often processed and transported to the cytosol, rendering them unavailable for HDR. We show that coupling CRISPR-Cpf1 (CRISPR from Prevotella and Francisella 1) to a CRISPR RNA (crRNA) array flanked with ribozymes, along with a DRT flanked with either ribozymes or crRNA targets, produces primary transcripts that self-process to release the crRNAs and DRT inside the nucleus. We replaced the rice acetolactate synthase gene (ALS) with a mutated version using a DNA-free ribonucleoprotein complex that contains the recombinant Cpf1, crRNAs, and DRT transcripts. We also produced stable lines with two desired mutations in the ALS gene using TT-HDR.


Assuntos
Marcação de Genes/métodos , Genes de Plantas , Recombinação Homóloga , Oryza/genética , Acetolactato Sintase/genética , Sequência de Bases , Biotecnologia , Sistemas CRISPR-Cas , DNA de Plantas/genética , Mutação , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , RNA de Plantas/genética , Proteínas Recombinantes/genética , Reparo de DNA por Recombinação , Moldes Genéticos
19.
Arch Immunol Ther Exp (Warsz) ; 67(3): 153-160, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30874838

RESUMO

Rheumatoid arthritis (RA) is a common autoimmune disease which impacts a large number of patients worldwide, and new drugs are required for lower the disease burden. Theaflavin-3, 3'-digallate (TFDG) is polyphenol exhibiting inhibition on inflammatory factors. This study aimed to explore the attenuation of TFDG on RA. The collagen-induced arthritis (CIA) mouse model was established and administered with TFDG. The arthritis score and incidence was recorded to assess the amelioration of TFDG on arthritis. Histopathological change of the mouse joint tissues was evaluated by haemotoxylin and eosin staining. The expression of pro-inflammatory mediators including interleukin (IL)-1ß, tumor necrosis factor (TNF)-α, and IL-6 was quantified by ELISA. The activation of nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) signaling pathways in the synovium were determined by Western blotting. In comparison with the control, administration of TFDG significantly reduced arthritis score and incidence in the CIA mouse model. TFDG significantly suppressed the expression of IL-1ß, TNF-α, and IL-6, as well as the levels of MMP-1, MMP-2, and MMP-3 in the synovium. TFDG also showed remarkable inhibition on the activation of NF-κB and the phosphorylation of P38, JNK2, and ERK. This study puts up evidence that TFDG exerts protection on RA via inhibiting the activation of NF-κB- and MAPK-signaling pathways.


Assuntos
Anti-Inflamatórios/farmacologia , Artrite Experimental/tratamento farmacológico , Artrite Reumatoide/tratamento farmacológico , Biflavonoides/farmacologia , Catequina/farmacologia , Ácido Gálico/análogos & derivados , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Animais , Anti-Inflamatórios/uso terapêutico , Artrite Experimental/imunologia , Artrite Experimental/patologia , Artrite Reumatoide/imunologia , Artrite Reumatoide/patologia , Biflavonoides/uso terapêutico , Catequina/uso terapêutico , Colágeno/administração & dosagem , Colágeno/imunologia , Avaliação Pré-Clínica de Medicamentos , Ácido Gálico/farmacologia , Ácido Gálico/uso terapêutico , Humanos , Interleucina-1beta/imunologia , Interleucina-1beta/metabolismo , Interleucina-6/imunologia , Interleucina-6/metabolismo , Articulações/efeitos dos fármacos , Articulações/imunologia , Articulações/patologia , Sistema de Sinalização das MAP Quinases/imunologia , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , NF-kappa B/imunologia , NF-kappa B/metabolismo , Fator de Necrose Tumoral alfa/imunologia , Fator de Necrose Tumoral alfa/metabolismo
20.
Angew Chem Int Ed Engl ; 58(16): 5236-5240, 2019 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-30809927

RESUMO

The development of efficient gene delivery vectors has faced two major challenges, namely endo- and lysosomal escape and intracellular release. To address these problems, we developed an oligonucleotide (ON)-template-assisted polymerization approach to create ON nanospheres as gene vectors. Guanidinium-containing disulfide monomers were organized on the ON templates to increase their effective local concentrations. Consequently, ring-opening disulfide-exchange polymerization between monomers was accelerated, further facilitating the self-assembly of ON nanospheres. The size of these nanospheres was controlled by varying the length of the ON templates. Importantly, the nanospheres can be directly delivered into the cytosol through an endocytosis-independent pathway, which is followed by intracellular depolymerization in the reductive cytosolic environment to release the packaged ONs, resulting in efficient gene silencing. The ON nanospheres thus hold great promise as candidates for gene therapy.


Assuntos
Técnicas de Transferência de Genes , Nanosferas/química , Oligonucleotídeos/química , Endocitose , Vetores Genéticos/síntese química , Vetores Genéticos/química , Oligonucleotídeos/síntese química , Tamanho da Partícula , Propriedades de Superfície
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA