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1.
Metab Eng ; 78: 72-83, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37201565

RESUMO

Microbial production of valuable bioproducts is a promising route towards green and sustainable manufacturing. The oleaginous yeast, Rhodosporidium toruloides, has emerged as an attractive host for the production of biofuels and bioproducts from lignocellulosic hydrolysates. 3-hydroxypropionic acid (3HP) is an attractive platform molecule that can be used to produce a wide range of commodity chemicals. This study focuses on establishing and optimizing the production of 3HP in R. toruloides. As R. toruloides naturally has a high metabolic flux towards malonyl-CoA, we exploited this pathway to produce 3HP. Upon finding the yeast capable of catabolizing 3HP, we then implemented functional genomics and metabolomic analysis to identify the catabolic pathways. Deletion of a putative malonate semialdehyde dehydrogenase gene encoding an oxidative 3HP pathway was found to significantly reduce 3HP degradation. We further explored monocarboxylate transporters to promote 3HP transport and identified a novel 3HP transporter in Aspergillus pseudoterreus by RNA-seq and proteomics. Combining these engineering efforts with media optimization in a fed-batch fermentation resulted in 45.4 g/L 3HP production. This represents one of the highest 3HP titers reported in yeast from lignocellulosic feedstocks. This work establishes R. toruloides as a host for 3HP production from lignocellulosic hydrolysate at high titers, and paves the way for further strain and process optimization towards enabling industrial production of 3HP in the future.


Assuntos
Lignina , Engenharia Metabólica , Engenharia Metabólica/métodos , Lignina/metabolismo
2.
J Chem Inf Model ; 63(24): 7669-7675, 2023 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-38061777

RESUMO

Generating new molecules with the desired physical or chemical properties is the key challenge of computational material design. Deep learning techniques are being actively applied in the field of data-driven material informatics and provide a promising way to accelerate the discovery of innovative materials. In this work, we utilize an invertible graph generative model to generate hypothetical promising high-temperature polymer dielectrics. A molecular graph generative model based on the invertible normalizing flow is trained on a data set containing 250k polymer molecular graphs (mostly generated by an RNN-based generative model) to learn the invertible transformations between latent distributions and molecular graph structures. When generating molecular graphs, a sample vector is drawn from the latent space, and then an adjacency tensor and node attribute matrix are generated through two invertible flows in two steps and assembled into a molecular graph. The model has the merits of exact likelihood training and an efficient one-shot generation process. The learned latent space is used to generate polymers with a high glass-transition temperature (Tg) and a wide band gap (Eg) for the application of high-temperature energy storage film capacitors. This work contributes to the efficient design of high-temperature polymer dielectrics by using deep generative models.


Assuntos
Polímeros , Temperatura , Modelos Moleculares , Probabilidade
3.
Nature ; 548(7667): 291-296, 2017 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-28792929

RESUMO

Stem mammaliaforms are Mesozoic forerunners to mammals, and they offer critical evidence for the anatomical evolution and ecological diversification during the earliest mammalian history. Two new eleutherodonts from the Late Jurassic period have skin membranes and skeletal features that are adapted for gliding. Characteristics of their digits provide evidence of roosting behaviour, as in dermopterans and bats, and their feet have a calcaneal calcar to support the uropagatium as in bats. The new volant taxa are phylogenetically nested with arboreal eleutherodonts. Together, they show an evolutionary experimentation similar to the iterative evolutions of gliders within arboreal groups of marsupial and placental mammals. However, gliding eleutherodonts possess rigid interclavicle-clavicle structures, convergent to the avian furculum, and they retain shoulder girdle plesiomorphies of mammaliaforms and monotremes. Forelimb mobility required by gliding occurs at the acromion-clavicle and glenohumeral joints, is different from and convergent to the shoulder mobility at the pivotal clavicle-sternal joint in marsupial and placental gliders.


Assuntos
Fósseis , Locomoção , Mamíferos/anatomia & histologia , Mamíferos/fisiologia , Filogenia , Animais , Aves/anatomia & histologia , China , Quirópteros/anatomia & histologia , Quirópteros/fisiologia , Dieta , Membro Anterior/anatomia & histologia , Membro Anterior/fisiologia , Mamíferos/classificação , Marsupiais/fisiologia , Dente Molar/anatomia & histologia , Dente Molar/fisiologia , Ombro/anatomia & histologia , Pele/anatomia & histologia , Crânio/anatomia & histologia
4.
Nature ; 548(7667): 326-329, 2017 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-28792934

RESUMO

Stem mammaliaforms are forerunners to modern mammals, and they achieved considerable ecomorphological diversity in their own right. Recent discoveries suggest that eleutherodontids, a subclade of Haramiyida, were more species-rich during the Jurassic period in Asia than previously recognized. Here we report a new Jurassic eleutherodontid mammaliaform with an unusual mosaic of highly specialized characteristics, and the results of phylogenetic analyses that support the hypothesis that haramiyidans are stem mammaliaforms. The new fossil shows fossilized skin membranes that are interpreted to be for gliding and a mandibular middle ear with a unique character combination previously unknown in mammaliaforms. Incisor replacement is prolonged until well after molars are fully erupted, a timing pattern unique to most other mammaliaforms. In situ molar occlusion and a functional analysis reveal a new mode of dental occlusion: dual mortar-pestle occlusion of opposing upper and lower molars, probably for dual crushing and grinding. This suggests that eleutherodontids are herbivorous, and probably specialized for granivory or feeding on soft plant tissues. The inferred dietary adaptation of eleutherodontid gliders represents a remarkable evolutionary convergence with herbivorous gliders in Theria. These Jurassic fossils represent volant, herbivorous stem mammaliaforms associated with pre-angiosperm plants that appear long before the later, iterative associations between angiosperm plants and volant herbivores in various therian clades.


Assuntos
Aclimatação , Evolução Biológica , Orelha Média/anatomia & histologia , Ingestão de Alimentos , Ecossistema , Fósseis , Mamíferos/anatomia & histologia , Mamíferos/fisiologia , Animais , Dieta , Herbivoria , Incisivo , Locomoção , Mamíferos/classificação , Dente Molar , Filogenia
5.
Environ Res ; 216(Pt 3): 114716, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36336092

RESUMO

Microplastics (MPs) have recently become an emerging environmental concern. Nevertheless, limited information is known about the adsorption of MPs for organic contaminants under combined heavy metals pollution, with an emphasis on the role of complexation. Thus, this study aims to comprehensively compare and investigate the adsorption performance of antibiotic tetracycline (TC) and ciprofloxacin (CIP) on two polar MPs (polyamide (PA) and polyvinyl chloride (PVC)) affected by Cu(II) and Cd(II) with contrasting complexation abilities. Batch adsorption experiments were used in combination with speciation calculation, zeta potential determination, FTIR spectroscopy characterization and investigation of the affinity of MPs for heavy metals. Results showed that the sorption kinetics and isotherms of TC and CIP on PA and PVC could be well fitted to pseudo-second-order and Langmuir models, respectively, both in the absence and presence of Cu and Cd, suggesting that multiple interactions and monolayer adsorption played an important role in the adsorption process. The presence of Cu substantially improved TC and CIP adsorption and obviously changed the pH dependence of their adsorption onto both MPs, which may result from the Cu-induced strong complexation with TC and CIP. The presence of Cd slightly enhanced TC adsorption on both MPs while reduced CIP adsorption especially on PVC, which may be ascribed to the Cd-induced cationic bridging effects in TC adsorption and the competitive adsorption of Cd in CIP adsorption. Therefore, the heavy metal-mediated complexation effects may play a dominant role in antibiotic adsorption by MPs only in the presence of heavy metals with strong complexation ability while the adsorption performance in the presence of heavy metals with negligible complexation capacity may be influenced by effects other than complexation. This study helps further understand the heavy metal-mediated adsorption behavior of organic contaminants on polar MPs and the role of complexation reactions therein.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Microplásticos , Adsorção , Ciprofloxacina/química , Plásticos , Antibacterianos , Cádmio , Cloreto de Polivinila , Metais Pesados/química , Tetraciclina/química , Poluentes Químicos da Água/análise
6.
BMC Med Genet ; 21(1): 114, 2020 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-32460726

RESUMO

BACKGROUND: The pathogenesis of dental caries remains unclear, with increasing evidence suggesting that genetic susceptibility plays an essential role. Previous studies have reported the association between genetic polymorphisms in lactotransferrin (LTF) and the risk of dental caries with inconsistent results. METHODS: A systematic literature search of the PubMed, Cochrane Library, HuGE and Google Scholar databases was performed by two authors independently for papers published before December 5, 2019 on the association between genetic variants in LTF and the risk of dental caries. We adopted the subsequent inclusion criteria to assess study eligibility: 1) The studies were based on human subjects; 2) the presence of dental caries should be screened for in both the case group and the control group; and 3) genotype data on variants in LTF were available in both the case group and the control group. We calculated odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) by using random-effects models to assess the association of genetic variants in LTF with the risk of dental caries. We also performed a gene-based analysis to explore the joint association of multiple genetic variants in LTF with the risk of dental caries. RESULTS: Our systematic literature search identified six relevant papers for analysis. We found no significant association between rs1126478 and the risk of dental caries when meta-analysing the genotype distribution between subjects with dental caries and those without dental caries (additive model: OR = 1.41; 95% CI = 0.98-2.02; P = 0.065). However, further analysis indicated that rs1126478 was associated with dental risk in subjects who had moderate or severe dental caries compared to those without dental caries (P < 0.0001). The gene-based analysis indicated that multiple genetic variants in LTF were jointly associated with the risk of dental caries (P = 0.002). CONCLUSIONS: The present meta-analysis revealed some evidence of the association between rs1126478 and dental caries and that multiple genetic variants in LTF are jointly associated with the risk of dental caries. Our findings need to be validated by larger studies that adjust for important confounding factors for the risk of dental caries.


Assuntos
Cárie Dentária/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Variação Genética , Lactoferrina/genética , Alelos , Biologia Computacional/métodos , Cárie Dentária/diagnóstico , Feminino , Humanos , Masculino , Modelos Genéticos , Razão de Chances , Viés de Publicação , Medição de Risco
7.
Mol Pharm ; 16(1): 71-85, 2019 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-30431285

RESUMO

Acute lung injury (ALI) is a serious illness without resultful therapeutic methods commonly. Recent studies indicate the importance of oxidative stress in the occurrence and development of ALI, and mitochondria targeted antioxidant has become a difficult and hot topic in the research of ALI. Therefore, a sialic acid (SA)-modified lung-targeted microsphere (MS) for ALI therapy are developed, with triphenylphosphonium cation (TPP)-modified curcumin (Cur-TPP) loaded, which could specifically target the mitochondria, increasing the effect of antioxidant. The results manifest that with the increase of microsphere, lung distribution of microsphere is also increased in murine mice, and after SA modification, the microsphere exhibits the ideal lung-targeted characteristic in ALI model mice, due to SA efficiently targeting to E-selectin expressed on inflammatory tissues. Further investigations indicate that SA/Cur-TPP/MS has better antioxidative capacity, decreases intracellular ROS generation, and increases mitochondrial membrane potential, contributing to a lower apoptosis rate in human umbilical vein endothelial cells (HUVECs) compared to H2O2 group. In vivo efficacy of SA/Cur-TPP/MS demonstrates that the inflammation has been alleviated markedly and the oxidative stress is ameliorated efficiently. Significant histological improvements by SA/Cur-TPP/MS are further proved via HE stains. In conclusion, SA/Cur-TPP/MS might act as a promising drug formulation for ALI therapy.


Assuntos
Curcumina/química , Microesferas , Mitocôndrias/metabolismo , Ácido N-Acetilneuramínico/química , Poliésteres/química , Polietilenoglicóis/química , Lesão Pulmonar Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/metabolismo , Animais , Sobrevivência Celular/efeitos dos fármacos , Curcumina/uso terapêutico , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos
8.
Int J Mol Sci ; 20(14)2019 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-31337083

RESUMO

Histone acetylation and deacetylation play essential roles in eukaryotic gene regulation. HD2 (HD-tuins) proteins were previously identified as plant-specific histone deacetylases. In this study, we investigated the function of the HDT1 gene in the formation of stem vascular tissue in Arabidopsis thaliana. The height and thickness of the inflorescence stems in the hdt1 mutant was lower than that of wild-type plants. Paraffin sections showed that the cell number increased compared to the wild type, while transmission electron microscopy showed that the size of individual tracheary elements and fiber cells significantly decreased in the hdt1 mutant. In addition, the cell wall thickness of tracheary elements and fiber cells increased. We also found that the lignin content in the stem of the hdt1 mutants increased compared to that of the wild type. Transcriptomic data revealed that the expression levels of many biosynthetic genes related to secondary wall components, including cellulose, lignin biosynthesis, and hormone-related genes, were altered, which may lead to the altered phenotype in vascular tissue of the hdt1 mutant. These results suggested that HDT1 is involved in development of the vascular tissue of the stem by affecting cell proliferation and differentiation.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Histona Desacetilases/genética , Desenvolvimento Vegetal/genética , Caules de Planta/genética , Feixe Vascular de Plantas/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Parede Celular/genética , Parede Celular/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Histona Desacetilases/metabolismo , Lignina/metabolismo , Mutação , Fenótipo , Caules de Planta/metabolismo , Feixe Vascular de Plantas/metabolismo , Xilema/citologia , Xilema/genética , Xilema/metabolismo
9.
Environ Sci Technol ; 50(5): 2514-21, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26824511

RESUMO

Graphene oxide (GO) materials have demonstrated considerable potential in next-generation water treatment membrane-based technologies, which include antimicrobial applications. GO antimicrobial properties can be further enhanced by preloading or chemically generating surface-associated nanoscale silver particles (nAg). However, for these systems, enhanced antimicrobial functionality decreases over time as a function of Ag mass loss via dissolution (as Ag(+)). In this work, we demonstrate facile photocatalytic in situ synthesis of nAg particles by crumpled GO-TiO2 (GOTI) nanocomposites as an approach to (re)generate, and thus maintain, enhanced antimicrobial activity over extended operation times. The described photocatalytic formation process is highly efficient and relatively fast, producing nAg particles over a size range of 40 to 120 nm and with active (111) planes. Additionally, we show in situ surface-based photocatalyzed synthesis of nAg particles at the surface of GOTI nanocomposite membrane assemblies, allowing for simultaneous filtration and disinfection. With ca. 3 log inactivation for both Escherichia coli and Bacillus subtilis, the described membrane assemblies with in situ formed nAg demonstrate enhanced antimicrobial activity compared to the GOTI membrane surface or the support membrane alone. Under typical conditions, the working and operational time (Ag dissolution time) is calculated to be over 2 orders of magnitude higher than the loading (synthesis) time (e.g., 123 h versus 0.5 h, respectively). Taken together, results highlight the described material-based process as a potentially novel antifouling membrane technology.


Assuntos
Filtração/instrumentação , Grafite/química , Nanopartículas/química , Fotoquímica/métodos , Prata/química , Anti-Infecciosos/farmacologia , Bacillus subtilis/efeitos dos fármacos , Desinfecção/métodos , Escherichia coli/efeitos dos fármacos , Membranas Artificiais , Nanocompostos/química , Titânio/química , Purificação da Água/métodos
10.
Macromol Rapid Commun ; 37(19): 1587-1592, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27461401

RESUMO

To enhance the limited degradability of poly(ethylene glycol) (PEG), a straightforward method of synthesizing poly[(ethylene glycol)-co-(glycolic acid)] (P(EG-co-GA)) via a ruthenium-catalyzed, post-polymerization oxyfunctionalization of various PEGs is developed. Using this method, a set of copolymers with GA compositions of up to 8 mol% are prepared with minimal reduction in molecular weight (<10%) when compared to their commercially available starting materials. The P(EG-co-GA) copolymers are shown to undergo hydrolysis under mild conditions.


Assuntos
Oxigênio/química , Poliésteres/síntese química , Polietilenoglicóis/química , Polimerização , Poliésteres/química , Polietilenoglicóis/síntese química
11.
J Food Sci Technol ; 53(11): 4043-4055, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28035160

RESUMO

The objective of this work was to study the correlation between the variation of phenolic compounds and sensory characteristics in white wine during bottle storage and to explore the compounds that affected sensory evolution. Chardonnay (Vitis vinifera L. cv.) dry white wines were bottled under six types of stoppers and stored for 18 months. The composition of phenolic compounds was analyzed, and the sensory attributes of these wines were evaluated by professional panel. Multivariate statistical analysis demonstrated that bottle aging period exhibited a more important effect on phenolic compound evolution than stopper type. Most of the phenolic compounds disappeared after 18 months of bottle storage, whereas the wine sensory attributes were significantly improved after 15-month of bottle aging. No strong correlation existed between the phenolic variation and the dissolved oxygen content. Wine color characteristics developed towards better quality accompanying with the reduction of detectable hydroxycinnamic acid derivatives and flavan-3-ols, while the wine mouth-feel was related mainly to gallic acid and ferulic acid ester. This work provided some references for wine producers to select appropriate storage duration for bottled white wine.

12.
Environ Sci Technol ; 49(11): 6846-54, 2015 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-25942505

RESUMO

In this work, we describe multifunctional, crumpled graphene oxide (CGO) porous nanocomposites that are assembled as advanced, reactive water treatment membranes. Crumpled 3D graphene oxide based materials fundamentally differ from 2D flat graphene oxide analogues in that they are highly aggregation and compression-resistant (i.e., π-π stacking resistant) and allow for the incorporation (wrapping) of other, multifunctional particles inside the 3D, composite structure. Here, assemblies of nanoscale, monomeric CGO with encapsulated (as a quasi core-shell structure) TiO2 (GOTI) and Ag (GOAg) nanoparticles, not only allow high water flux via vertically tortuous nanochannels (achieving water flux of 246 ± 11 L/(m(2)·h·bar) with 5.4 µm thick assembly, 7.4 g/m(2)), outperforming comparable commercial ultrafiltration membranes, but also demonstrate excellent separation efficiencies for model organic and biological foulants. Further, multifunctionality is demonstrated through the in situ photocatalytic degradation of methyl orange (MO), as a model organic, under fast flow conditions (tres < 0.1 s); while superior antimicrobial properties, evaluated with GOAg, are observed for both biofilm (contact) and suspended growth scenarios (>3 log effective removal, Escherichia coli). This is the first demonstration of 3D, crumpled graphene oxide based nanocomposite structures applied specifically as (re)active membrane assemblies and highlights the material's platform potential for a truly tailored approach for next generation water treatment and separation technologies.


Assuntos
Grafite/química , Membranas Artificiais , Nanocompostos/química , Nanotecnologia/métodos , Purificação da Água/métodos , Catálise/efeitos da radiação , Contagem de Colônia Microbiana , Escherichia coli/crescimento & desenvolvimento , Luz , Testes de Sensibilidade Microbiana , Nanocompostos/ultraestrutura , Espectroscopia de Infravermelho com Transformada de Fourier , Titânio/química , Ultrafiltração
13.
Environ Sci Technol ; 48(20): 11892-900, 2014 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-25222070

RESUMO

Engineered, superparamagnetic, iron oxide nanoparticles (IONPs) have significant potential as platform materials for environmental sensing, imaging and remediation due to their unique size, physicochemical and magnetic properties. To this end, controlling the size and surface chemistry of the materials is crucial for such applications in the aqueous phase, and in particular, for porous matrixes with particle-surface interaction considerations. In this study, superparamagnetic, highly monodispersed 8 nm IONPs were synthesized and transferred into water as stable suspensions (remaining monodispersed) by way of an interfacial oleic acid bilayer surface. Once stabilized and characterized, particle-particle and model surface interactions (deposition and release) were quantitatively investigated and described systematically as a function of ionic strength (IS) and type with time-resolved dynamic light scattering (DLS), zeta potential, and real-time quartz crystal microbalance with dissipation monitoring (QCM-D) measurements. The critical coagulation concentration (CCC) for oleic acid bilayer coated iron oxide nanoparticles (OA-IONPs) were determined to be 710 mM for NaCl (matching DLVO predictions) and 10.6 mM for CaCl2, respectively. For all conditions tested, surface deposition kinetics showed stronger, more favorable interactions between OA-IONPs and polystyrene surfaces compared to silica, which is hypothesized to be due to increased particle-surface hydrophobic interactions (when compared to silica surfaces).


Assuntos
Dextranos/química , Meio Ambiente , Nanopartículas de Magnetita/química , Nanotecnologia/métodos , Cinética , Nanopartículas de Magnetita/ultraestrutura , Concentração Osmolar , Poliestirenos/química , Técnicas de Microbalança de Cristal de Quartzo , Dióxido de Silício/química , Soluções , Eletricidade Estática , Propriedades de Superfície , Água/química
14.
ACS Biomater Sci Eng ; 9(7): 3953-3961, 2023 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-34060803

RESUMO

Understanding the structure-property relationship of biological materials, such as bones, teeth, cells, and biofilms, is critical for diagnosing diseases and developing bioinspired materials and structures. The intrinsic multiphase heterogeneity with interfaces places great challenges for mechanical modeling. Here, we develop an image-based polygonal lattice model for simulating the mechanical deformation of biological materials with complicated shapes and interfaces. The proposed lattice model maintains the uniform meshes inside the homogeneous phases and restricts the irregular polygonal meshes near the boundaries or interfaces. This approach significantly simplifies the mesh generation from images of biological structures with complicated geometries. The conventional finite element simulations validate this polygonal lattice model. We further demonstrate that the image-based polygonal lattices generate meshes from images of composite structures with multiple inclusions and capture the nonlinear mechanical deformation. We conclude the paper by highlighting a few future research directions that will benefit from the functionalities of polygonal lattice modeling.


Assuntos
Modelos Biológicos , Próteses e Implantes , Simulação por Computador
15.
Tissue Cell ; 84: 102197, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37595532

RESUMO

Dental pulp angiogenesis is a committed step in pulp regeneration therapy, and exosomes provide a new cell-free choice for tissue regeneration. This study revealed the underlying regulatory mechanism of exosomes from stem cells of the apical papilla (SCAPs) under hypoxic state on angiogenesis of human umbilical vein endothelial cells (HUVECs) in vitro. Exosomes extracted from normoxia or hypoxia-pretreated SCAPs were co-cultured with HUVECs, and hypoxia pretreatment increased the release of exosomes and the internalization of exosomes by HUVECs. Compared to normoxic SCAPs-derived exosomes, exosomes from hypoxic SCAPs were found to promote cell proliferation and migration in HUVECs, as it was respectively determined by Cell Counting Kit-8, RT-qPCR and Transwell assay. Besides, hypoxia-educated SCAPs-exosomes especially enhanced the angiogenesis abilities of HUVECs in vitro, which were confirmed by tube formation assay and RT-qPCR detection of angiogenesis-related molecular markers. Interestingly, we found that the hypoxia inducible factor-1α (HIF-1α)/Notch1 signaling pathway was activated in hypoxic SCAPs, and protein jagged-1 (JAG1) was delivered by hypoxic SCAPs-derived exosomes to increase vascular endothelial growth factor (VEGF) production in HUVECs. Moreover, exogenous interference of JAG1 expression in HUVECs partially neutralized the activities of hypoxic SCAPs-exosomes in promoting cell proliferation, migration and tube formation of HUVECs. In summary, this study elucidates that exosomes from hypoxic SCAPs shows high potential to promote angiogenesis in vitro through the HIF-1α/JAG1/VEGF signaling cascade, which may provide a new perspective for the development of vascular reconstruction measures during dental regeneration engineering.


Assuntos
Exossomos , Fator A de Crescimento do Endotélio Vascular , Humanos , Polpa Dentária , Regeneração , Fatores de Crescimento do Endotélio Vascular , Células Endoteliais da Veia Umbilical Humana , Hipóxia , Proteína Jagged-1
16.
J Control Release ; 361: 681-693, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37595667

RESUMO

The two-signal model of T cell activation has helped shape our understanding of the adaptive immune response for over four decades. According to the model, activation of T cells requires a stimulus through the T cell receptor/CD3 complex (signal 1) and a costimulatory signal 2. Stimulation of activatory signals via T cell agonists has thus emerged. However, for a robust T cell activation, it necessitates not only the presence of both signal 1 and signal 2, but also a high signaling strength. Herein, we report a photo-activable nano-agonist for the two-signal model of T cell in vivo activation. A UV-crosslinkable polymer is coated onto upconversion nanoparticles with satisfactory NIR-to-UV light conversion efficiency. Then dual signal molecules, i.e., signal 1 and signal 2, are conjugated to the polymer end to yield the photo-activable T cell nano-agonist. In melanoma and breast cancer models, photo-activable nano-agonist could bind onto corresponding activatory receptors on the surface of T cells, but has limited activity without the application of NIR light (absence of photo-crosslinking of receptors and consequently a poor signaling strength). While when the NIR light is switched on locally, T cells in tumor are remarkably activated and kill tumor cells effectively. Moreover, we do not observe any detectable toxicities related to the photo-activable nano-agonist. We believe with two activatory signals being simultaneously strengthened by local photo-switched crosslinking, T cells realize a robust and selective activation in tumor and, consequently contribute to an enhanced and safe tumor immunotherapy.


Assuntos
Melanoma , Nanopartículas , Humanos , Imunoterapia , Ativação Linfocitária , Polímeros
17.
Macromol Rapid Commun ; 33(5): 407-13, 2012 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-22290870

RESUMO

The design and synthesis of a new porous organic polymer (POP) incorporated with cobalt carbonyl complexes through built-in bipyridinic coordination sites for hydrogen storage are described. A thermal activation process was developed to remove the ligated carbonyl and carbon dioxide in order to expose the cobalt atomically inside of porous structure. Various spectroscopic and physical characterization techniques were used to study the coordinated Co sites and the POP's surface property. Upon thermal activation, this new cobalt-containing POP showed improved hydrogen uptake capacity and isosteric heat of adsorption.


Assuntos
Cobalto/química , Hidrogênio/química , Polímeros/química , Adsorção , Dióxido de Carbono/química , Fluorenos/química , Polimerização , Polímeros/síntese química , Porosidade , Piridinas/química , Termodinâmica
18.
J Mater Chem B ; 10(16): 3016-3022, 2022 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-35332893

RESUMO

Organic photosensitizers are of great interest in cancer diagnosis and treatments such as fluorescence imaging, photodynamic therapy (PDT), and photothermal therapy (PTT). However, their poor aqueous solubility, inadequate photostability and unsatisfactory photophysical parameters limit their clinical application. Herein, we report the construction of liposome encapsulating cyanine dye Cypate (Lipo-Cy) with enhanced nonradiative transition for efficient cancer therapy. After being loaded in liposomes, Cypate molecules are spatially confined within the hydrophobic lipid bilayer, thereby causing much better stability, higher photothermal conversion efficiency, and increased singlet oxygen quantum yield than free Cypate via enhanced nonradiative transition through π-π aggregation. Lipo-Cy further enhanced the cellular uptake of Cypate, as well as preferable tumor accumulation and retention, leading to abundant intracellular singlet oxygen and potent hyperthermia at the tumor for effective PTT synergized PDT, even at dosages 10 times less than free Cypate. The Lipo-Cy exhibited superior anticancer efficiency, showing great prospects for clinical translation.


Assuntos
Hipertermia Induzida , Neoplasias , Corantes/uso terapêutico , Humanos , Lipossomos/uso terapêutico , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Fototerapia/métodos , Oxigênio Singlete
19.
Mar Pollut Bull ; 184: 114184, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36183509

RESUMO

During the COVID-19 pandemic, disposable surgical masks were generally disinfected and reused due to mask shortages. Herein, the role of disinfected masks as a source of microplastics (MPs) and nanoplastics (NPs) was investigated. The amount of MPs and NPs released from masks disinfected by UV ranged from 1054 ± 106 to 2472 ± 70 and from 2.55 ± 0.22 × 109 to 6.72 ± 0.27 × 109 particles/piece, respectively, comparable to that of the undisinfected masks, and the MPs were changed to small-sized particles. The amount of MPs and NPs released after alcohol and steam treatment were respectively lower and higher than those from undisinfected masks, and MPs were shifted to small-sized particles. The amount of MPs and NPs released in water after autoclaving was lower than for undisinfected masks. In all, the amount of fibers released after disinfection decreased greatly, and certain disinfection processes were found to increase the amount of small-sized NPs released from masks into aqueous environments.


Assuntos
COVID-19 , Poluentes Químicos da Água , Humanos , Microplásticos , Plásticos , Desinfecção , Pandemias , Água , Vapor , Poluentes Químicos da Água/análise
20.
Nat Prod Res ; 36(6): 1593-1598, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33624565

RESUMO

Toona sinensis is a medicinal and edible plant that belongs to the genus Toona of family Meliaceae. Phytochemical investigations carried out on this plant, seven apotirucallane-type triterpenoids (1-7), two cycloartane-type triterpenoids (8-9), four sterols (10-13), two sesquiterpenes (14-15), four phenols (16-19), and one lignin (20) were isolated from the pericarp of T. sinensis by silica gel column and preparative middle pressure liquid chromatography. Their structures were identified by interpretation of NMR and comparison with those reported in the literature. Compounds 11-12, 15-16, and 18 were isolated from the family Meliaceae, compounds 13-14 were obtained from the genus Toona, and compound 19 was obtained from T. sinensis for the first time. Additionally, the cytotoxicity and polyol pathway (PP) inhibitory activities of active constituents were evaluated in rat glomerular mesangial cells cultured under high glucose conditions, suggesting their potential application for a PP inhibitor.


Assuntos
Meliaceae , Toona , Animais , Meliaceae/química , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polímeros , Ratos
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