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1.
Chem Commun (Camb) ; 55(83): 12507-12510, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31576386

RESUMO

Charge reduction and neutralization of electro-sprayed peptides are realized by selective gas-phase photocleavage of tailored covalent tags. The concept is demonstrated with four model peptides in positive and negative ion modes and tagged insulin as the largest construct.


Assuntos
Insulina/química , Peptídeos/química , Vácuo , Íons/química , Estrutura Molecular , Processos Fotoquímicos
2.
Chem Pharm Bull (Tokyo) ; 67(10): 1168-1170, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31582638

RESUMO

In this study, the adsorption capability of Fe-HT3.0 for nitrite and nitrate ions in a binary solution system was evaluated. It was found that the amount of nitrite and nitrate ions adsorbed in a single solution (1.19 and 1.27 mmol/g, respectively) was higher than that in a binary solution (0.36 and 0.90 mmol/g, respectively). Equilibrium adsorption was attained within 6-24 h. The adsorption data were fitted to a pseudo-second-order model (correlation coefficient: 0.999), and indicated that the adsorption of both nitrite and nitrate ions is controlled by chemical sorption. Additionally, the binding energies before and after the adsorption of nitrite and nitrate ions in the binary solution system were measured. After adsorption, new nitrogen peaks (approx. 399 and 403 eV) were detected. The results of this study show the potential of Fe-HT3.0 for the removal of nitrite and nitrate ions from aqueous solution systems.


Assuntos
Ferro/química , Hidróxido de Magnésio/química , Nitratos/química , Nitritos/química , Adsorção , Íons/química , Tamanho da Partícula , Soluções
3.
Chem Commun (Camb) ; 55(83): 12463-12466, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31576854

RESUMO

Herein, an ultrasensitive electrochemical biosensor is proposed for the quantification of the Flu A virus biomarker DNA (fDNA), and is based on loop-mediated isothermal amplification-generated hydrogen ions (LAMP-H+) which induce the formation of the dimer i-motif structure (DiMS) for signal transduction, coupled with exonuclease III (ExoIII)-assisted DNA walking for signal dual-amplification.


Assuntos
Técnicas Biossensoriais , DNA Viral/análise , Técnicas Eletroquímicas , Vírus da Influenza A/química , Técnicas de Amplificação de Ácido Nucleico , Prótons , Biomarcadores/análise , Dimerização , Íons/química
4.
Phys Chem Chem Phys ; 21(36): 19795-19804, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31482888

RESUMO

Allostery plays important roles in the regulation of many biological processes, such as signal transduction and transcriptional regulation. Although great advances have been achieved in understanding the allosteric mechanism through experimental and theoretical investigations, the details of the allosteric process are still not clear. Here, using the N-terminal domain of calmodulin (nCaM) as the model protein, we reported the atomic level characterization of the allosteric process induced by Ca2+ binding through extensive and unbiased molecular dynamics simulations. In two trajectories, it was found that Ca2+ first binds to EF-hand 2 and then induces the conformational transformation of nCaM from the Apo to Holo state assisted by second Ca2+ binding to EF-hand 1 completely. The binding order was consistent with a recent experimental result. The simulations also indicated that the two EF-hands changed conformations synergistically and the EF-hand 2 showed an earlier and more gradual conformational transition. Meanwhile, the allosteric process of nCaM triggered by Ca2+ binding might be completed within hundreds of nanoseconds in a two-state-like manner. This was validated by biased simulations, in which the Ca2+ ions were restrained near the binding sites. This work provides the molecular details of the conformational transition of nCaM triggered by Ca2+ binding.


Assuntos
Cálcio/química , Calmodulina/química , Íons/química , Simulação de Acoplamento Molecular , Domínios Proteicos , Ligação Proteica , Conformação Proteica
5.
Chem Commun (Camb) ; 55(75): 11299-11302, 2019 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-31475999

RESUMO

Fabrication of ordered assemblies with protein nanocages as building blocks has attracted great attention. Here, we re-engineered the exterior surface of the smallest natural nanocage, DNA-binding protein from starved cells (Dps), to yield a highly ordered architecture triggered by zinc ions. The resulting architecture possesses a bcc superstructure, the assembly and disassembly of which are reversible and can be regulated by the salt concentration.


Assuntos
Proteínas de Ligação a DNA/química , Nanoestruturas/química , Engenharia de Proteínas , Zinco/química , Proteínas de Ligação a DNA/síntese química , Íons/química , Tamanho da Partícula , Sais/química , Propriedades de Superfície
6.
Inorg Chem ; 58(17): 11294-11299, 2019 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-31411862

RESUMO

The first two examples of polyoxopalladates(II) (POPs) containing tetravalent metal ion guests, [MO8Pd12(PO4)8]12- (M = SnIV, PbIV), have been prepared and structurally characterized in the solid state, solution, and gas phase. The interactions of the metal ion guests and the palladium-oxo shell were studied by theoretical calculations. The POPs were shown to possess anticancer activity by causing oxidative stress inducing caspase activation and consecutive apoptosis of leukemic cells.


Assuntos
Antineoplásicos/farmacologia , Metais Pesados/química , Compostos Organometálicos/farmacologia , Polímeros/química , Antineoplásicos/síntese química , Antineoplásicos/química , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Células HL-60 , Humanos , Íons/química , Modelos Moleculares , Compostos Organometálicos/síntese química , Compostos Organometálicos/química
7.
J Chem Theory Comput ; 15(8): 4526-4534, 2019 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-31314524

RESUMO

We investigate the photoinduced ultrafast charge migration phenomenon in the glycine molecule using a recently proposed nonequilibrium Green's functions (NEGF) approach. We first consider the dynamics resulting from the sudden removal of an electron in the valence shells, finding a satisfactory agreement with available data. Then we explicitly simulate the laser-induced photoionization process and study the evolution of the system after the pulse. We disentangle polarization and correlation effects in the electron dynamics and assign the main frequencies to specific elements of the reduced one-particle density matrix. We show that electronic correlations renormalize the bare frequencies, redistribute the spectral weights, and give rise to new spectral features.


Assuntos
Elétrons , Glicina/química , Íons/química , Lasers , Modelos Moleculares , Processos Fotoquímicos
8.
Environ Monit Assess ; 191(8): 488, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31292792

RESUMO

This paper presents the adsorption capacity of a biosorbent derived from the inner part of durian (Durio zibethinus) rinds, which are a low-cost and abundant agro-waste material. The durian rind sorbent has been successfully utilized to remove lanthanum (La) and yttrium (Y) ions from their binary aqueous solution. The effects of several adsorption parameters including contact time, pH, concentrations of La and Y, and temperature on the removal of La and Y ions were investigated. The adsorption isotherm and kinetics of the metal ions were also evaluated in detail. Both La and Y ions were efficiently adsorbed by the biosorbent with optimum adsorption capacity as high as 71 mg La and 35 mg Y per gram biosorbent, respectively. The simultaneous adsorption of La and Y ions follows Langmuir isotherm model, due to the favorable chelation and strong chemical interactions between the functional groups on the surface of the biosorbent and the metal ions. The addition of oxygen content after adsorption offers an interpretation that the rare-earth metal ions are chelated and incorporated most probably in the form of metal oxides. With such high adsorption capacity of La and Y ions, the durian rind sorbent could potentially be used to treat contaminated wastewater containing La and Y metal ions, as well as for separating and extracting rare-earth metal ions from crude minerals.


Assuntos
Lantânio/química , Poluentes Químicos da Água/química , Ítrio/química , Adsorção , Bombacaceae , Concentração de Íons de Hidrogênio , Íons/química , Cinética , Lantânio/análise , Metais , Temperatura Ambiente , Água/química , Poluentes Químicos da Água/análise , Ítrio/análise
9.
J Phys Chem Lett ; 10(14): 4123-4128, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31287699

RESUMO

Delivering potential theranostic metal complexes into preferential cellular targets is becoming of increasing interest. Here we report that nuclear uptake of a cell-impermeable DNA "light-switching" Ru(II)-polypyridyl complex can be significantly facilitated by chlorophenolate counter-anions, which was found, unexpectedly, to be correlated positively with the binding stability but inversely with the lipophilicity of the formed ion pairs.


Assuntos
Clorofenóis/química , Complexos de Coordenação/química , DNA/química , Piridinas/química , Rutênio/química , Química Física , Células HeLa , Humanos , Íons/química , Estrutura Molecular , Polímeros/química
10.
J Chromatogr A ; 1602: 188-198, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31147156

RESUMO

A liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS)-based dereplicative method was developed for identifying oplopane- and bisabolane-type sesquiterpenoids from buds of Tussilago farfara L. The analysis of these chemical analogues, sesquiterpene esters, is challenging by MS-based nontargeted metabolomic approaches because of their in-source fragmentation and structural diversity. To profile these sesquiterpenoids, four diagnostic ions (m/z 215.143, 217.158, 229.123, and 231.138) were suggested in the positive ion mode and the developed method utilized two sequential MS/MS scan modes to identify common skeletons and investigate the fragmentation patterns of their parent molecules. Precursor ion scan by triple quadrupole MS/MS provided the parent molecular ions from their diagnostic ions, and product ion scan by quadrupole time-of-flight MS/MS confirmed their fragmentation behaviors. Under the optimized UHPLC-MS/MS method, 74 sesquiterpenoids were characterized from the Farfarae Flos and 11 compounds were isolated for the method validation. Among those compounds, three sesquiterpenoids were newly separated from the Farfarae Flos. Furthermore, the diagnostic ions and the MS/MS fragment behaviors were applied to the accurate quantification of the 8 isolated sesquiterpenoids. Therefore, the developed LC-MS/MS-based method highlighted the chemical composition of the Farfarae Flos and could be extended to the screening and quantification of other sesquiterpene esters.


Assuntos
Técnicas de Química Analítica/métodos , Espectrometria de Massas , Sesquiterpenos/química , Tussilago/química , Cromatografia Líquida , Íons/química , Sesquiterpenos/isolamento & purificação
11.
Environ Sci Pollut Res Int ; 26(23): 24062-24074, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31228065

RESUMO

Polyvinyl alcohol (PVA) filled with different kinds of ZnO whisker was prepared by chemical cross-linking reaction. It was found that the ZnO whiskers dispersed uniformly after being modified by 3-aminopropyltriethoxysilane (APTES). The PVA/tetrapod-shaped ZnO (PVA/tetra-ZnO) composites showed better adsorption performance than other kinds of PVA/ZnO composites. The framework-supported pore-channel structure was beneficial for the transmission and adsorption of heavy metal ions, and the formation of "brush" pore-channel of PVA/tetra-ZnO composites can effectively retain and capture the heavy metal ions. The PVA/tetra-ZnO composites presented well adsorption on Pb(II), Cd(II), and Cr(III) ions than Ni(II) and showed relatively selective removal on Pb(II) and Cr(III) ions. The adsorbed heavy metal ions presented gradient distribution with high content in the out layer and low content in the inner layer. Pb(II) adsorption capacity qe increased gradually with the increase of initial solution concentration and contact time which tended to be stable at 400 mg/L and 800 min. The maximal adsorption capacity qm obtained by nonlinear fitting reached to about 116 mg/g which was very close to the experiment data. Adsorption isotherm results indicated the monolayer adsorption process of the Langmuir model and the adsorption kinetics data fitted well to the pseudo-second-order model. The adsorption process was spontaneous and the high temperature was in favor of adsorption. The adsorption mechanism was explored as the combination of coordination and ion exchange. Besides, the PVA/tetra-ZnO composites exhibited better stress stability, thermo stability, and favorable regeneration than neat PVA.


Assuntos
Chumbo/análise , Álcool de Polivinil/química , Poluentes Químicos da Água/análise , Adsorção , Concentração de Íons de Hidrogênio , Íons/química , Cinética , Chumbo/química , Metais Pesados , Poluentes Químicos da Água/química , Óxido de Zinco/química
12.
Biophys Chem ; 252: 106207, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31252378

RESUMO

Conformational changes in bio-molecular systems are fundamental to several biological processes. It is important to study changes in responses of underlying microscopic variables, like dihedral angles as conformational change takes place. We perform all-atom simulations and modelling via Langevin equation to illustrate the changes in structural and dynamic responses of dihedral angles of calcium ion binding residues of different proteins in metal ion free (apo) and bound (holo) states. The equilibrium distributions of dihedral angles in apo- and holo-states represent structural response. Our studies show the presence of dihedrals with multiple peaks (isomeric states) separated by barrier heights is more frequent in apo- than in holo-state. The relaxation time-scale of dihedral fluctuations is found to increase linearly with decreasing barrier height due to more frequent barrier re-crossing events. The slow kinetic response of the dihedrals also contributes to slowing down of macro-scale fluctuations, which may be useful to understand kinetics of various bio-molecular processes.


Assuntos
Cálcio/metabolismo , Metaloproteínas/química , Metaloproteínas/metabolismo , Simulação de Dinâmica Molecular , Sítios de Ligação , Cálcio/química , Íons/química , Íons/metabolismo , Conformação Proteica
13.
Bioresour Technol ; 289: 121675, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31238288

RESUMO

The study highlights one pot conversion of hardwood biomass into Total reducing sugars (TRS) and 5-Hydroxymethyl Furfural (5-HMF). Synergistic effect of dilute H2SO4 and ionic liquid in a reaction time of 60 min at 120 °C was examined. Hydrolysis of Catalpa (Catalpa Bignonioides), Indian Rosewood (Dalbergia Sissoo), Chinaberry (Melia Azedarach) and Babool (Acacia Nilotica) catalyzed by modified activated carbon leads to significant product yield. Maximum yield was obtained using Catalpa wood i.e. 92.67% TRS and 70.36% 5-HMF under optimized conditions. Biomass before and after pretreatment subjected to FT-IR, XRD and compositional analysis determined the structural changes. Further, the effect of electrolytes namely; AlCl3, MgCl2, NaCl and KCl were evaluated. Results revealed that using optimized concentration of each electrolyte promoted the conversion to 96.56% (TRS) and 86.23% (5-HMF) using AlCl3 (4 wt%) for Catalpa wood. Addition of DMSO with optimized electrolyte concentration improves the partition coefficient (3.3) and yield to 88.29% (5-HMF).


Assuntos
Biomassa , Carvão Vegetal/química , Catálise , Hidrólise , Líquidos Iônicos/química , Íons/química , Espectroscopia de Infravermelho com Transformada de Fourier , Madeira/química
14.
Food Chem ; 293: 66-73, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151650

RESUMO

A simple biologically active phenolic methyl gallate (MeG) was used as a model compound to identify the nature of the complexes it formed with Al3+, Fe3+, Cu2+, and Sn2+ as analyzed by ultraviolet (UV) spectroscopic and computational methods. The results showed that, among all the metal ions studied in the present study, MeG has the highest formation constant with Al3+, and the complexation between MeG and metal ions is a pH-dependent reaction. At pH 6.0, complexes with a stoichiometry of 1:1 were formed with Al3+, Fe3+, and Sn2+, whereas 2:3 complexes were formed with Cu2+. Using a functional density quantum-chemical method, it was shown that the ligand involved in the complexation of MeG-Al undergoes significant changes in electronic delocalization. Modeling of electronic spectra with water as solvent shows high reproducibility for the experimental features of the complexes. The calculations confirm that chelation of Al3+ occurs at the double-deprotonated phenolic hydroxyls.


Assuntos
Ácido Gálico/análogos & derivados , Metais/química , Teoria da Densidade Funcional , Ácido Gálico/química , Concentração de Íons de Hidrogênio , Íons/química , Espectrofotometria Ultravioleta
15.
Inorg Chem ; 58(16): 10483-10500, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31246017

RESUMO

The f-block elements, which comprise both the lanthanide and actinide series, possess interesting spectroscopic, magnetic, and nuclear properties that make them uniquely suited for a range of biomedical applications. In this Forum Article, we provide a concise overview on the different ways that these elements are employed in medicine, highlighting their dual implementation in both diagnostic and therapeutic applications. A key requirement for the use of these labile metal ions in medicine is a suitable chelating agent that controls their in vivo biodistribution. Toward this goal, we also report our research describing the synthesis and characterization of a rigid 18-membered macrocycle called CHX-macropa, an analogue of the previously reported nonrigid ligand macropa (J. Am. Chem. Soc. 2009, 131, 3331). The lanthanide coordination chemistry of CHX-macropa is explored in detail by pH potentiometry and density functional theory (DFT) calculations. These studies reveal that CHX-macropa exhibits an enhanced thermodynamic selectivity for large over small lanthanides in comparison to its nonrigid analogue macropa. DFT calculations suggest that a key factor in the enhanced selectivity of this ligand for the large f-block ions is its rigid macrocyclic core, which cannot adequately distort to interact effectively with small ions. On the basis of its high affinity for large f-block ions, the design strategies implemented in CHX-macropa may be valuable for applying these elements in the diagnosis or treatment of disease.


Assuntos
Antineoplásicos/química , Elementos da Série dos Lantanídeos/química , Compostos Macrocíclicos/química , Animais , Teoria da Densidade Funcional , Humanos , Íons/química , Ligantes , Estrutura Molecular , Tamanho da Partícula , Soluções , Termodinâmica
16.
Environ Sci Pollut Res Int ; 26(24): 24933-24945, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31243653

RESUMO

The energy budget is an indicator of an organism's overall condition. Changes in energy reserves and/or energy consumption have been used as biomarkers of toxic stress. To understand the effects of different forms and concentrations of Zn and the costs of effective Zn regulation by the earthworm Eisenia andrei, we performed a toxicokinetic experiment in which individuals were sampled over time to determine the available energy reserves (total carbohydrate, protein, and lipid content), energy consumption (measured at the cellular level and as the whole-animal respiration rate), and internal Zn concentration. The earthworms were exposed to ZnCl2 or zinc nanoparticles (ZnO-NPs) in Lufa 2.2 soil for 21 days (contamination phase), followed by 14 days of elimination in clean soil (decontamination phase). Carbohydrates were the only energy reserves with significantly lower levels following ZnO-NP 1000 treatment than following other treatments (p ≤ 0.00001) in the contamination phase. The total available energy reserves and protein content did not differ among treatments, but a significant effect of exposure time was observed (p ≤ 0.0001). Exposure to Zn (both ions and NPs) increased energy consumption at the cellular level, reflecting the high energy demand of the stress response. The results indicated that E. andrei can regulate internal Zn concentrations efficiently, regardless of form or concentration, without considerable impact on energy reserves or respiration rate.


Assuntos
Íons/química , Nanopartículas/toxicidade , Oligoquetos/efeitos dos fármacos , Poluentes do Solo/análise , Óxido de Zinco/toxicidade , Zinco/análise , Animais , Íons/metabolismo , Taxa Respiratória , Solo , Zinco/química , Óxido de Zinco/química
17.
Chem Commun (Camb) ; 55(52): 7458-7461, 2019 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-31184643

RESUMO

The development of a sensitive and reliable method for the detection of bioaccumulated heavy metal toxins is highly desirable for biotoxicity evaluation. However, the conventional biotoxicity evaluation method based on luminescent bacteria suffers from only being able to detect the overall toxicity without selectivity in light-off detection mode. Although various synthetic fluorescent probes have been developed for the selective detection of heavy metal ions, they usually suffer from aggregation-caused quenching after local accumulation in biological systems. To tackle these challenges, we herein develop a dual detection strategy for bioaccumulated Hg2+ based on turn-off of the bioluminescence of P. phosphoreum bacteria by disrupting the quorum sensing system and turn-on of the photoluminescence of an aggregation-induced emission (AIE) probe by forming aggregates with Hg2+ inside the bacteria. It is expected that the dual detection strategy would find broad applications in the evaluation of bioaccumulated toxins.


Assuntos
Mercúrio/química , Photobacterium/química , Corantes Fluorescentes/química , Íons/química , Luz , Medições Luminescentes/métodos , Mercúrio/farmacologia , Microscopia Confocal , Photobacterium/isolamento & purificação , Teoria Quântica , Percepção de Quorum/efeitos dos fármacos
18.
J Chromatogr A ; 1601: 45-52, 2019 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-31182303

RESUMO

The highly selective enrichment of phosphopeptides is vital for the research of phosphorylated proteomics. Herein, a magnetic bimetallic metal-organic framework (MOF) with Zr-O and Ti-O clusters (denoted as Fe3O4@SiO2@(Zr-Ti-PTA)15) has been fabricated using a layer-by-layer assembly approach via the coordination of metal ions with carboxyl groups. The composite has large specific surface area (135.84 m2 g-1) and superparamagnetism (62.03 emu g-1). Compared with single-metal cluster MOF, the Fe3O4@SiO2@(Zr-Ti-PTA)15 showed higher binding capacity (100 mg g-1), enhanced affinity, better selectivity (nß-casein : nBSA = 1 : 2000) and sensitivity (0.3 fmol/µL) towards phosphopeptides due to the combination of the dual metal clusters. Furthermore, the Fe3O4@SiO2@ (Zr-Ti-PTA)15 was successfully applied to extracting phosphopeptides from non-fat milk tryptic digest, and 10 mono-phosphopeptides and 22 multi-phosphopeptides were captured. As a result, 1294 phosphopeptides (476 multi-phosphopeptides and 818 mono-phosphopeptides) were selectively extracted and detected from tryptic digest of rat brain extract, indicating its great application potential in phosphorylated proteomics research.


Assuntos
Magnetismo , Estruturas Metalorgânicas , Fosfopeptídeos/isolamento & purificação , Proteômica/métodos , Animais , Caseínas/metabolismo , Íons/química , Estruturas Metalorgânicas/química , Fosforilação , Ratos , Dióxido de Silício/química , Titânio/química
19.
Mol Med Rep ; 19(6): 5039-5045, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31059063

RESUMO

Wound healing is a dynamic process that involves highly coordinated cellular events, including proliferation and migration. Oral gingival fibroblasts serve a central role in maintaining oral mucosa homeostasis, and their functions include the coordination of physiological tissue repair. Recently, surface pre­reacted glass­ionomer (S­PRG) fillers have been widely applied in the field of dental materials for the prevention of dental caries, due to an excellent ability to release fluoride (F). In addition to F, S­PRG fillers are known to release several types of ions, including aluminum (Al), boron (B), sodium (Na), silicon (Si) and strontium (Sr). However, the influence of these ions on gingival fibroblasts remains unknown. The aim of the present study was to examine the effect of various concentrations of an S­PRG filler eluate on the growth and migration of gingival fibroblasts. The human gingival fibroblast cell line HGF­1 was treated with various dilutions of an eluent solution of S­PRG, which contained 32.0 ppm Al, 1,488.6 ppm B, 505.0 ppm Na, 12.9 ppm Si, 156.5 ppm Sr and 136.5 ppm F. Treatment with eluate at a dilution of 1:10,000 was observed to significantly promote the migration of HGF­1 cells. In addition, the current study evaluated the mechanism underlying the mediated cell migration by the S­PRG solution and revealed that it activated the phosphorylation of extracellular signal­regulated kinase 1/2 (ERK1/2), but not of p38. Furthermore, treatment with a MEK inhibitor blocked the cell migration induced by the solution. Taken together, these results suggest that S­PRG fillers can stimulate HGF­1 cell migration via the ERK1/2 signaling pathway, indicating that a dental material containing this type of filler is useful for oral mucosa homeostasis and wound healing.


Assuntos
Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Alumínio/química , Boro/química , Linhagem Celular , Movimento Celular , Proliferação de Células/efeitos dos fármacos , Fibroblastos/citologia , Fibroblastos/metabolismo , Gengiva/citologia , Humanos , Íons/química , Íons/farmacologia , Fosforilação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Silício/química , Sódio/química , Estrôncio/química , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
20.
Environ Int ; 128: 407-416, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31078875

RESUMO

The dissemination and propagation of antibiotic resistance genes (ARGs) is an emerging global health concern, and the potential effects of nanomaterials on ARGs fates have drawn much attention recently. In the current study, the effects of metallic nanoparticles on ARGs occurrence of leachate culturable microbiota were investigated by four typical metal and metal oxide nanoparticles (Cu, Zn, CuO, and ZnO). The ARGs diversity was remarkably decreased during the cultivation and enrichment of leachate microbiota, and their abundances decreased for 1.4-3.2 orders of magnitude. The presence of nanoparticles facilitated the ARGs attenuation, and the magnitude of effects depended on types of nanoparticles and ARGs. Metal oxide nanoparticles caused more remarkable effects than metal nanoparticles. Mechanism analysis indicated that bacterial growth was inhibited, and the dissolved metal ions from nanoparticles partially contributed to nanoparticles decreasing ARGs. Flow cytometry experiments further confirmed that nanoparticles could enter bacterial cells, and then induce excessive reactive oxygen species (ROS) generation and increase membrane permeability. Finally, the possible mechanisms were put forward, and the structural equation models (SEM) differentiated the contribution of different factors shaping ARGs. The dissolved metal ions and growth inhibition caused by nanoparticles decreased ARGs transfer frequencies via exerting excessive metal stress and lowering population density. On the other hand, nanoparticles were incorporated into the cells, and then induced the generation of ROS, which might facilitate ARGs horizontal transfer via increasing membrane permeability, or decrease ARGs via the damage of genomic and plasmid DNA. Therefore, nanoparticles could affect ARGs fates via several ways, and combined effects finally determined the ARGs variations.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Nanopartículas Metálicas , Microbiota/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Cobre/farmacologia , Resistência Microbiana a Medicamentos/genética , Íons/química , Microbiota/genética , Microbiota/fisiologia , Estresse Oxidativo/efeitos dos fármacos , RNA Bacteriano/análise , RNA Ribossômico 16S/análise , Águas Residuárias/microbiologia , Poluentes Químicos da Água , Zinco/farmacologia , Óxido de Zinco/farmacologia
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