Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.396
Filtrar
1.
Chemosphere ; 263: 127952, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32828058

RESUMO

Forage grasses have recently received a remarkable amount of attention as promising candidates for decontaminating metal-polluted soils, but this strategy is time-consuming and inefficient. The present study aimed to address the beneficial effects of screened plant growth-promoting rhizobacteria (PGPR) strains Bacillus sp. EhS5 and EhS7 on perennial ryegrass and tall fescue. Single or combined inoculation considerably increased the biomass yield and Cu content of inoculated ryegrass compared with uninoculated plants, thereby enhancing the extraction efficiency at different Cu contamination levels. Bioaugmentation did not show a positive impact on the improvement of fescue's phytoextraction efficiency. Principal component analysis (PCA) and Pearson correlation coefficient results identified root development and photosynthesis as the key variables influencing ryegrass biomass. Antioxidant activities and Cu bioavailability are the key variables influencing Cu accumulation. The inoculated ryegrass showed improved photosynthetic status as the photosystem II system efficiency parameters increased and energy dissipation in the form of heat (DIo/RC) decreased with the help of PGPR. The root length, diameter, surface area, and forks of inoculated ryegrass increased remarkably. The levels of scavengers of reactive oxygen species were enhanced in these plants. Moreover, PGPR significantly increased soil Cu bioavailability by secreting siderophores and organic acid and by increasing soil organic carbon content. Dual inoculation showed better results than individual inoculation in improving ryegrass growth and Cu translocation under high Cu contamination level according to PCA. This study systematically explored the effects and mechanisms of the Bacillus-ryegrass combined remediation and provided a novel method for cleaning Cu-contaminated sites.


Assuntos
Cobre/metabolismo , Lolium/fisiologia , Poluentes do Solo/metabolismo , Bacillus , Biodegradação Ambiental , Disponibilidade Biológica , Biomassa , Carbono/farmacologia , Cobre/toxicidade , Lolium/crescimento & desenvolvimento , Desenvolvimento Vegetal/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Solo , Poluentes do Solo/toxicidade
2.
AAPS PharmSciTech ; 21(8): 322, 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-33200276

RESUMO

This study reports the generation of novel, aqueous-dispersible plunoric-CD nanoconjugates encapsulating doxorubicin (Dox). The fluorescent CD were conjugated with plunoric F127 to form biocompatible delivery matrix and were further loaded with fluorescent Dox molecule. The resulting particles were analyzed for multiplexed bioimaging and targeted drug delivery. Physicochemical and optical characterization demonstrated discrete fluorescence from CD (blue emission) and Dox (orange emission) counterparts. In vitro drug release profile signifies higher and rapid release of Dox from Dox@Plu-CD under acidic conditions compared to physiological pH. Thus, the acid liable Dox@Plu-CD linkage can easily break in the cytosol of tumor cells because of low pH compared to normal cells thus conferring minimal damage to healthy cells. Moreover, results form in vitro cell viability assay suggest the cyto-compatibility of Plu-CD delivery matrix to HEK293 and HeLa cell lines. However, Dox@Plu-CD induced cell death and morphological alterations in HeLa cell lines, signifying pH-responsive effect of the prepared complex. Confocal imaging signified that Dox@Plu-CD effectively penetrates HeLa cells, and the released Dox binds to the cell nucleus and induces oxidative stress. The prepared Dox@Plu-CD thus behaved as efficient fluorescent probes allowing multiplexed bioimaging (blue and orange) of HeLa cells along with improved therapeutic potential.Graphical abstract.


Assuntos
Ácidos/química , Antibióticos Antineoplásicos/química , Carbono/química , Doxorrubicina/química , Poloxâmero/química , Antibióticos Antineoplásicos/farmacologia , Carbono/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos , Fluorescência , Corantes Fluorescentes/química , Células HEK293 , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Preparações Farmacêuticas
3.
Int J Nanomedicine ; 15: 9049-9059, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33235451

RESUMO

Introduction: The charcoal processed product of Paeoniae Radix Alba (PRA), PRA Carbonisata (PRAC), has long been used for its hepatoprotective effects. However, the material basis and mechanism of action of PRAC remain unclear. Aim: To explore the hepatoprotective effects of Paeoniae Radix Alba Carbonisata-derived carbon dots (PRAC-CDs). Methods: PRAC-CDs were characterized using transmission electron microscopy, high-resolution transmission electron microscopy, ultraviolet, fluorescence, Fourier transform infrared and X-ray photoelectron spectroscopy, X-ray diffraction, and high-performance liquid chromatography. The hepatoprotective effect of PRAC-CDs was evaluated and confirmed using the classic carbon tetrachloride acute liver injury model. Results: PRAC-CDs averaged 1.0-2.4 nm in size and exhibited a quantum yield of 5.34% at a maximum excitation wavelength of 320 nm and emission at 411 nm. PRAC-CDs can reduce the ALT and AST levels of mice with carbon tetrachloride-induced acute liver injury and have a mitigating effect on the rise in TBA and TBIL. More interestingly, PRAC-CDs can significantly reduce MDA and increase SOD levels, demonstrating that PRAC-CDs can improve the body's ability to scavenge oxygen free radicals and inhibit free radical-induced liver cell lipid peroxidation, thereby preventing liver cell damage. Conclusion: These results demonstrate the remarkable hepatoprotective effects of PRAC-CDs against carbon tetrachloride-induced acute liver injury, which provide new insights into potential biomedical and healthcare applications of CDs.


Assuntos
Carbono/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Fígado/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Pontos Quânticos/química , Animais , Ductos Biliares/efeitos dos fármacos , Tetracloreto de Carbono , Morte Celular/efeitos dos fármacos , Carvão Vegetal , Cromatografia Líquida de Alta Pressão , Fígado/metabolismo , Masculino , Malondialdeído/metabolismo , Camundongos , Espectroscopia Fotoeletrônica , Pontos Quânticos/ultraestrutura , Células RAW 264.7 , Superóxido Dismutase/metabolismo , Transaminases/metabolismo
4.
Aquat Toxicol ; 228: 105633, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33069118

RESUMO

Microbial community functional diversity enhances the degradation of organic matter and pollutants in the environment, but there is a growing concern that these ecosystem services may be altered by the introduction of emerging environmental contaminants including silver nanoparticles (AgNPs) into aquatic systems. We added 0, 25, 50, 75, 100, and 125 mg L-1 (nominal concentrations) of citrate-AgNP and polyvinylpyrrolidone-AgNP (PVP-AgNP) each to freshwater sediment and examined their antimicrobial effects on microbial communities using community-level physiological profiling. The results showed that citrate-AgNP decreased the overall microbial catabolic activity by 80% from 1.16 ± 0.02 to 0.23 ± 08 while PVP-AgNP decreased the catabolic activity by 51% from 1.25 ± 0.07 to 0.61 ± 0.19 at 125 mg L-1. Citrate-AgNP and PVP-AgNP caused a statistically significant reduction in substrate richness and substrate diversity that decreased microbial functional diversity. AgNPs decreased microbial catabolic capability and functional diversity at concentrations ranging from 0.12 ± 0.04 to 0.43 ± 0.07 mg Ag kg-1 which are lower than the predicted concentrations in freshwater sediment. To our knowledge, this is the first study to demonstrate inhibition of microbial functional diversity by citrate-AgNP and PVP-AgNP in a pathogen impaired stream. Citrate-AgNP caused greater inhibition of carbon substrate utilization but amino acids, carbohydrates, and carboxylic acids were the most affected carbon groups which led to a shift in the metabolic fingerprint pattern of the microbial community. AgNPs decreased the catabolic capability and the ability of the microbial community to degrade organic matter and a variety of pollutants in the environment.


Assuntos
Metabolômica , Nanopartículas Metálicas/toxicidade , Microbiota/efeitos dos fármacos , Prata/toxicidade , Poluentes Químicos da Água/toxicidade , Biodiversidade , Carbono/farmacologia , Ácido Cítrico , Sedimentos Geológicos/química , Nanopartículas Metálicas/ultraestrutura , Análise de Componente Principal
5.
Ecotoxicol Environ Saf ; 206: 111220, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32877887

RESUMO

Functional carbon nanodots (FCNs) with multiple chemical groups have great impact on the growth regulation of plants. To understand the role of the chemical groups, FCNs were reduced from the raw material by pyrolysis method and hydrolysis method. The chemical structure of these materials were characterized by using TGA, TEM, FT-IR, XPS, Raman and elementary analysis. The raw and reduced FCNs were used as plants growth regulators in culture medium of Arabidopsis thaliana. Our results indicate there is a strong correlation between the physiological responses of plants and the surface chemistries (especially carboxyl group and ester group) of the nanomaterials. The quantum-sized FCNs with multiple carboxyl groups and ester groups show better aqueous dispersity and can induce various positive physiological responses in Arabidopsis thaliana seedlings compared with the FCNs decorated without carboxyl and ester as well as aggregated FCNs. The raw FCNs present higher promotion capacity in plants biomass and roots length, and the quantum-sized FCNs are easier to be absorbed by plants and generate more positive effects on plants.


Assuntos
Arabidopsis/efeitos dos fármacos , Carbono/farmacologia , Nanopartículas/química , Desenvolvimento Vegetal/efeitos dos fármacos , Reguladores de Crescimento de Planta/farmacologia , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Biomassa , Carbono/química , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Tamanho da Partícula , Reguladores de Crescimento de Planta/química , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Plântula/efeitos dos fármacos , Plântula/genética , Plântula/crescimento & desenvolvimento , Propriedades de Superfície
6.
PLoS One ; 15(9): e0238689, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32903284

RESUMO

MOTIVATION: Determining intracellular metabolic flux through isotope labeling techniques such as 13C metabolic flux analysis (13C-MFA) incurs significant cost and effort. Previous studies have shown transcriptomic data coupled with constraint-based metabolic modeling can determine intracellular fluxes that correlate highly with 13C-MFA measured fluxes and can achieve higher accuracy than constraint-based metabolic modeling alone. These studies, however, used validation data limited to E. coli and S. cerevisiae grown on glucose, with significantly similar flux distribution for central metabolism. It is unclear whether those results apply to more diverse metabolisms, and therefore further, extensive validation is needed. RESULTS: In this paper, we formed a dataset of transcriptomic data coupled with corresponding 13C-MFA flux data for 21 experimental conditions in different unicellular organisms grown on varying carbon substrates and conditions. Three computational flux-balance analysis (FBA) methods were comparatively assessed. The results show when uptake rates of carbon sources and key metabolites are known, transcriptomic data provides no significant advantage over constraint-based metabolic modeling (average correlation coefficients, transcriptomic E-Flux2 0.725 and SPOT 0.650 vs non-transcriptomic pFBA 0.768). When uptake rates are unknown, however, predictions obtained utilizing transcriptomic data are generally good and significantly better than those obtained using constraint-based metabolic modeling alone (E-Flux2 0.385 and SPOT 0.583 vs pFBA 0.237). Thus, transcriptomic data coupled with constraint-based metabolic modeling is a promising method to obtain intracellular flux estimates in microorganisms, particularly in cases where uptake rates of key metabolites cannot be easily determined, such as for growth in complex media or in vivo conditions.


Assuntos
Bactérias/genética , Ciclo do Carbono/genética , Transcriptoma/genética , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/genética , Bacillus subtilis/crescimento & desenvolvimento , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Carbono/farmacologia , Ciclo do Carbono/efeitos dos fármacos , Árvores de Decisões , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Synechococcus/efeitos dos fármacos , Synechococcus/genética , Synechococcus/crescimento & desenvolvimento , Synechocystis/efeitos dos fármacos , Synechocystis/genética , Synechocystis/crescimento & desenvolvimento
7.
Int J Food Microbiol ; 334: 108835, 2020 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-32898829

RESUMO

Use of carbon dots (CDs) combined with radio frequency (RF) was applied to pasteurize and reduce the microorganism population in order to improve the quality of boiled gansi dish. CDs were prepared from banana using hydrothermal method, and characterized by using TEM, XRD and FTIR. The minimal inhibitory concentration (MIC) test showed CDs can efficiently inactivate Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Bacillus subtilis (B. subtilis). This study also evaluated the effectiveness of five treatments, including CDs alone, CDs combined RF (CDRF) heating for different time (8 min, 12 min, and 16 min), and high pressure steam (HPS) sterilization of boiled gansi dish inoculated with B. subtilis. After CDRF treated for 8 min, 12 min, and 16 min, the center temperature of samples reached to 78.92, 87.77 and 93.82 °C, and the colony forming units (CFU) of B. subtilis reduced by 2.13, 3.62, and 4.63 log, respectively. Samples with CDRF12 treatment, exhibited better product quality as evidenced by reduced loss of texture, flavor, and sensory as compared with HPS sample. The results indicated that CDRF treatment has a great potential to produce packaged boiled gansi dish with high product quality.


Assuntos
Carbono/farmacologia , Alimentos em Conserva/microbiologia , Pasteurização/métodos , Pontos Quânticos/química , Ondas de Rádio , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Bactérias/efeitos da radiação , Carbono/química , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Qualidade dos Alimentos , Calefação/métodos
8.
Int J Nanomedicine ; 15: 5545-5559, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32848387

RESUMO

Introduction: Although carbon nanospheres (CNPs) are promising nanomaterials in cancer treatment, how they affect prostate cancer (PCa) remains unclear. Methods: In this study, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy were used to confirm the successful synthesis of CNPs. CCK-8, flow cytometry, Transwell, wound healing, Western blot and immunohistochemistry (IHC) assays were performed to evaluate the antitumor effect of CNPs toward the two kinds of prostate cancer cell lines PC3 and DU145. Results: Our results showed that CNPs inhibited cell growth, invasion, and migration and induced apoptosis and autophagy in PCa cells. Multifactor detection of a single Akt phosphorylation pathway and Western blot results suggested the suppression of 4E-BP1 in PCa cells after incubation with CNPs. The results from animal experiments also suggested the antitumor effect of CNPs and reduced 4E-BP1 expression in PCa tissue samples from BALB/c nude mice administered a local subcutaneous injection of CNPs.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Antineoplásicos/química , Antineoplásicos/farmacologia , Carbono/farmacologia , Proteínas de Ciclo Celular/metabolismo , Nanosferas/química , Neoplasias da Próstata/tratamento farmacológico , Animais , Autofagia/efeitos dos fármacos , Carbono/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Humanos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Microscopia Eletrônica de Varredura , Nanosferas/uso terapêutico , Fosforilação/efeitos dos fármacos , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Análise Espectral Raman , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Int J Nanomedicine ; 15: 5473-5489, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32801701

RESUMO

Introduction: Biofilms protect bacteria from antibiotics and this can produce drug-resistant strains, especially the main pathogen of periodontitis, Porphyromonas gingivalis. Carbon quantum dots with various biomedical properties are considered to have great application potential in antibacterial and anti-biofilm treatment. Methods: Tinidazole carbon quantum dots (TCDs) and metronidazole carbon quantum dots (MCDs) were prepared by a hydrothermal method with the clinical antibacterial drugs tinidazole and metronidazole, respectively. Then, TCDs and MCDs were characterized by transmission electron microscopy, UV-visible spectroscopy, infrared spectroscopy and energy-dispersive spectrometry. The antibacterial effects were also investigated under different conditions. Results: The TCDs and MCDs had uniform sizes. The results of UV-visible and energy-dispersive spectrometry confirmed their important carbon polymerization structures and the activity of the nitro group, which had an evident inhibitory effect on P. gingivalis, but almost no effect on other bacteria, including Escherichia coli, Staphylococcus aureus and Prevotella nigrescens. Importantly, the TCDs could penetrate the biofilms to further effectively inhibit the growth of P. gingivalis under the biofilms. Furthermore, it was found that the antibacterial effect of TCDs lies in its ability to impair toxicity by inhibiting the major virulence factors and related genes involved in the biofilm formation of P. gingivalis, thus affecting the self-assembly of biofilm-related proteins. Conclusion: The findings demonstrate a promising new method for improving the efficiency of periodontitis treatment by penetrating the P. gingivalis biofilm with preparations of nano-level antibacterial drugs.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Porphyromonas gingivalis/efeitos dos fármacos , Pontos Quânticos/química , Animais , Antibacterianos/efeitos adversos , Aderência Bacteriana/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Carbono/química , Carbono/farmacologia , Escherichia coli/efeitos dos fármacos , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Humanos , Metronidazol/química , Metronidazol/farmacologia , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Transmissão , Periodontite/microbiologia , Porphyromonas gingivalis/genética , Porphyromonas gingivalis/fisiologia , Coelhos , Espectrofotometria Ultravioleta , Staphylococcus aureus/efeitos dos fármacos , Tinidazol/química , Tinidazol/farmacologia , Fatores de Virulência/antagonistas & inibidores
10.
Chemosphere ; 261: 127798, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32750617

RESUMO

Mining activities lead to important physical, chemical and biological effects on soil properties, generating severe impacts in the establishment and maintenance of vegetation. Assisted phytoremediation can be considered an environmentally friendly approach for soil remediation. In this study, two mining soils (PORT and GAM) were treated with 10%, by mass, of the following amendments: manure biochars prepared at 450 °C (BMW450) and 600 °C (BMW600), hydrochars prepared by hydrothermal carbonization (HTC) of manure at 190 °C (HWM190) and 240 °C (HMW240) and manure waste (MW). Brassica napus was used as a phytoextraction species. After 45 days of plant growth, soil samples were widely characterized, including microbial biomass carbon, enzymatic activity and metal content. In addition, plant biomass production, bioconcentration factor, translocation factor and metal uptake were determined. Experimental results showed that addition of biochars improved the As uptake by Brassica napus in both soils but just in the roots increasing bioconcentration factor between 22.1 and 39.5% for GAM soil and between 28.6 and 53.4% for PORT soil. Brassica napus cannot be considered as Zn accumulator in GAM soil samples and in the case of PORT samples, only the addition of BMW600 and HMW240 enhanced the phytoextraction process of Zn on the roots. Soil enzyme activity improved in hydrochar amended soils.


Assuntos
Biodegradação Ambiental , Brassica napus/crescimento & desenvolvimento , Carvão Vegetal/química , Esterco , Poluentes do Solo/análise , Biomassa , Carbono/farmacologia , Metais/farmacologia , Mineração , Solo/química
11.
Sci Rep ; 10(1): 12662, 2020 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-32728167

RESUMO

Metastatic breast cancer dominates the female cancer-related mortality. Tumour-associated molecules represents a crucial for early disease detection and identification of novel therapeutic targets. Nanomaterial technologies provide promising novel approaches to disease diagnostics and therapeutics. In the present study we extend the investigations of antitumoral properties of Carbon Dots prepared from N-hydroxyphthalimide (CD-NHF) precursor. We evaluate the effect of CD-NHF on tumour cell migration and invasion in vitro and their impact on tumour progression using an in vivo model. Furthermore, we investigate the molecular mechanisms involved in CD-NHF antitumour effects. In vivo mammary tumours were induced in Balb/c female mice by injecting 4T1 cells into the mammary fat pad. Conditional treatment with CD-NHF significantly impair both migration and invasion of metastatic breast cancer cells. The presence of CD-NHF within the 3D cell cultures strongly inhibited the malignant phenotype of MDA-MB-231, 4T1 and MCF-7 cells in 3D culture, resulting in culture colonies lacking invasive projections and reduction of mammospheres formation. Importantly, breast tumour growth and metastasis dissemination was significantly reduced upon CD-NHF treatments in a syngeneic mouse model and is associated with down-regulation of Ki67 and HSP90 expression. CD-NHF nanostructures provide exciting perspective for improving treatment outcome in breast cancer.


Assuntos
Antineoplásicos/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Carbono/administração & dosagem , Ftalimidas/administração & dosagem , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Carbono/química , Carbono/farmacologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Chaperonina 60/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Antígeno Ki-67/metabolismo , Células MCF-7 , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Mitocondriais/metabolismo , Invasividade Neoplásica , Metástase Neoplásica , Ftalimidas/química , Ftalimidas/farmacologia , Pontos Quânticos , Ensaios Antitumorais Modelo de Xenoenxerto
12.
PLoS One ; 15(7): e0236188, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32701995

RESUMO

Microalgae and cyanobacteria are considered as important model organisms to investigate the biology of photosynthesis; moreover, they are valuable sources of biomolecules for several biotechnological applications. Understanding the species-specific traits of photosynthetic electron transport is extremely important, because it contributes to the regulation of ATP/NADPH ratio, which has direct/indirect links to carbon fixation and other metabolic pathways and thus overall growth and biomass production. In the present work, a cuvette-based setup is developed, in which a combination of measurements of dissolved oxygen, pH, chlorophyll fluorescence and NADPH kinetics can be performed without disturbing the physiological status of the sample. The suitability of the system is demonstrated using a model cyanobacterium Synechocystis sp. PCC6803, as well as biofuel-candidate microalgae species, such as Chlorella sorokiniana, Dunaliella salina and Nannochloropsis limnetica undergoing inorganic carbon (Ci) limitation. Inorganic carbon limitation, induced by photosynthetic Ci uptake under continuous illumination, caused a decrease in the effective quantum yield of PSII (Y(II)) and loss of oxygen-evolving capacity in all species investigated here; these effects were largely recovered by the addition of NaHCO3. Detailed analysis of the dark-light and light-dark transitions of NADPH production/uptake and changes in chlorophyll fluorescence kinetics revealed species- and condition-specific responses. These responses indicate that the impact of decreased Calvin-Benson cycle activity on photosynthetic electron transport pathways involving several sections of the electron transport chain (such as electron transfer via the QA-QB-plastoquinone pool, the redox state of the plastoquinone pool) can be analyzed with high sensitivity in a comparative manner. Therefore, the integrated system presented here can be applied for screening for specific traits in several significant species at different stages of inorganic carbon limitation, a condition that strongly impacts primary productivity.


Assuntos
Carbono/farmacologia , Cianobactérias/fisiologia , Compostos Inorgânicos/farmacologia , Microalgas/fisiologia , Fotossíntese , Chlorella/efeitos dos fármacos , Chlorella/fisiologia , Clorofila/metabolismo , Cianobactérias/efeitos dos fármacos , Transporte de Elétrons/efeitos dos fármacos , Fluorescência , Cinética , Microalgas/efeitos dos fármacos , NADP/metabolismo , Oxigênio/metabolismo , Fotossíntese/efeitos dos fármacos , Complexo de Proteína do Fotossistema II/metabolismo , Teoria Quântica , Synechocystis/efeitos dos fármacos , Synechocystis/fisiologia
13.
Cell Prolif ; 53(5): e12821, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32364266

RESUMO

OBJECTIVES: Photodynamic therapy (PDT) is a promising approach for cancer treatment, and the underlying signalling pathway changes has been carried out for studying the PDT mechanisms, but is majorly limited to organic photosensitizers (PSs). For the emerging nano-PSs typically possessing higher 1 O2 quantum yield, few mechanistic studies were carried out, which limited their further applications in clinical therapeutics. PI3K/Akt signalling pathway, a most frequently activated signalling network in cancers, could promote cancer cell survival, but was seldom reported in previous PDT studies mediated by nano-PSs. MATERIALS AND METHODS: Sulphur doped carbon dots (S-CDs) was prepared via a hydrothermal synthetic route and was characterized by transmission electron microscopy, X-ray photoelectron spectroscopy and so on. CCK-8 assay and Annexin V/PI staining were performed to demonstrate the death of cancer cells, Western blot, RT-PCR and immunofluorescence were employed to explore the underlying mechanism, and variation of PI3K/Akt and other signalling pathways was detected by Western blot. RESULTS: S-CDs was successfully synthesized, and it was much more efficient compared with classic organic PSs. S-CDs could induce cancer cell death through mitochondria mediated cell apoptosis with the imbalance of Bcl-2 family proteins and caspase cascade via several signalling pathways. Low concentration of S-CDs could effectively inhibit PI3K/Akt pathway and promote p38/JNK pathway, on one way inhibiting cancer cell survival and on the other way promoting cell apoptosis. CONCLUSIONS: Herein, we found that S-CDs acted as an inhibitor of the PI3K/Akt pathway for efficient cancer cell killing, thus yielding in a higher PDT performance over the existing photosensitizers.


Assuntos
Carbono/farmacologia , Neoplasias/tratamento farmacológico , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos , Enxofre/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Neoplasias/metabolismo , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo
14.
Int J Food Microbiol ; 326: 108650, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32402916

RESUMO

Use of carbon dots (CDs) in combination with aqueous chitosan solution to extend shelf life and improve stability of soy milk was investigated. Soy milk samples with chitosan solution (0.00%, 0.08%, 0.12%, 0.16% and 0.20%) and banana-based CDs (4%, 6% and 8%) were prepared and stored at room temperature (25-30 °C) for shelf life evaluation. Soy milk with 0.16% chitosan solution exhibited improved stability as evident by increased viscosity, stability coefficient, zeta potential and decreased centrifugation rate compared with soy milk without chitosan. The suitable amount of carbon dots could effectively inhibit the growth of Escherichia coli, Staphylococcus aureus and Bacillus subtilis. Soy milk with 0.16% chitosan and 8% CDs exhibited longer shelf life and significantly lower total bacterial count after storage at room temperature for up to 4 days. Electronic nose-based flavor characteristics of all treated soy milk samples were not far from that of the control sample.


Assuntos
Bacillus subtilis/crescimento & desenvolvimento , Quitosana/farmacologia , Escherichia coli/crescimento & desenvolvimento , Armazenamento de Alimentos/estatística & dados numéricos , Leite de Soja/metabolismo , Staphylococcus aureus/crescimento & desenvolvimento , Bacillus subtilis/efeitos dos fármacos , Carbono/farmacologia , Escherichia coli/efeitos dos fármacos , Contaminação de Alimentos/análise , Pontos Quânticos , Staphylococcus aureus/efeitos dos fármacos , Paladar , Água/farmacologia
15.
PLoS One ; 15(4): e0232461, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32348373

RESUMO

AST-120 (Kremezin) is used to treat progressive chronic kidney disease (CKD) by adsorbing uremic toxin precursors produced by gut microbiota, such as indole and phenols. In this study, we propose that AST-120 reduces indole level, consequently suppresses indole effects on induction of drug tolerance and virulence in Escherichia coli including enterohaemorrhagic strains. In experiments, AST-120 adsorbed both indole and tryptophan, a precursor of indole production, and led to decreased expression of acrD and mdtEF which encode drug efflux pumps, and elevated glpT, which encodes a transporter for fosfomycin uptake and increases susceptibility to aztreonam, rhodamine 6G, and fosfomycin. AST-120 also decreased the production of EspB, which contributes to pathogenicity of enterohaemorrhagic E. coli (EHEC). Aztreonam, ciprofloxacin, minocycline, trimethoprim, and sulfamethoxazole were also adsorbed by AST-120. However, fosfomycin, in addition to rifampicin, colistin and amikacin were not adsorbed, thus AST-120 can be used together with these drugs for therapy to treat infections. These results suggest another benefit of AST-120, i.e., that it assists antibacterial chemotherapy.


Assuntos
Antibacterianos/farmacologia , Carbono/farmacologia , Infecções por Escherichia coli/tratamento farmacológico , Escherichia coli/efeitos dos fármacos , Indóis/metabolismo , Óxidos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Farmacorresistência Bacteriana/efeitos dos fármacos , Escherichia coli Êntero-Hemorrágica/efeitos dos fármacos , Escherichia coli Êntero-Hemorrágica/metabolismo , Escherichia coli Êntero-Hemorrágica/patogenicidade , Escherichia coli/metabolismo , Escherichia coli/patogenicidade , Infecções por Escherichia coli/microbiologia , Humanos , Virulência/efeitos dos fármacos
16.
Cell Prolif ; 53(4): e12786, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32301195

RESUMO

OBJECTIVES: Photodynamic therapy (PDT) is a novel non-invasive therapeutic method, which has been widely applied for the treatment of human oral cancers. However, the problems of undesirable singlet oxygen (1 O2 ) quantum yields and long-term phototoxicity were inevitable during the application of traditional photosensitizers. Therefore, it is necessary to explore novel photosensitizers for the improvement of therapeutic effects. In our study, the sulphur-doped carbon dots (S-CDs) of high yield of singlet oxygen (1 O2 ) were synthesized as a nano-photosensitizer for OSCC to improve the PDT efficacy in clinical practice. MATERIALS AND METHODS: After synthesis of the novel S-CDs, the size, morphologic characteristics, surface potential and yield of singlet oxygen (1 O2 ) were determined. In vitro study was performed to compare the therapeutic effect as well as the biocompatibility of the novel S-CDs to those of 5-ALA. Besides, possible mechanism of action was illustrated. RESULTS: After synthesis of the novel S-CDs, the size, morphologic characteristics, surface potential and yield of singlet oxygen (1 O2 ) were determined. In vitro study was performed to compare the therapeutic effect as well as the biocompatibility of the novel S-CDs to those of 5-ALA. Besides, possible mechanism of action was illustrated. CONCLUSIONS: These data from the in vitro study demonstrated the promising safety profile of the low dose (nmol/L) S-CDs, which indicated the novel S-CDs could be used as a promising photodynamic agent for oral cancer therapy.


Assuntos
Carbono/farmacologia , Carcinoma de Células Escamosas/tratamento farmacológico , Neoplasias Bucais/tratamento farmacológico , Fármacos Fotossensibilizantes/farmacologia , Enxofre/farmacologia , Apoptose/efeitos dos fármacos , Carbono/química , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Humanos , Modelos Moleculares , Neoplasias Bucais/patologia , Nanopartículas/química , Nanopartículas/ultraestrutura , Fotoquimioterapia , Fármacos Fotossensibilizantes/química , Enxofre/química
17.
Mater Sci Eng C Mater Biol Appl ; 109: 110517, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32228977

RESUMO

A novel nanocarrier based-on hollow mesoporous carbon nanospheres (HMCNs) with primary amines on its surface, a large cavity, and good hydrophilicity was synthesized by a hydrothermal reaction. The primary amine functionalities on the mesoporous carbon were used as the initiation sites for growing poly (epichlorohydrin) (PCH) chains. The chlorine groups in the side chain of PCH were replaced with imidazole as the pendant groups. Calcium chloride (CaCl2) was applied as a capping agent. The coordination bonding was formed between pendant imidazole groups and calcium ions. Doxorubicin (DOX) was selected as a model of hydrophilic anticancer drug and was loaded onto the nanocarrier and released through the cleavage of the pH-sensitive coordination bonding. The gating mechanism enables the nanocarrier to store and release the calcium ions and the DOX molecules trapped in the pores. MTT assay toward HeLa cells indicated that the nanocarrier had low toxicity because of the surface modification with the oxygen-rich polymer. The cellular uptake of the pH-sensitive nanocarrier for HeLa cancer cell lines was confirmed by CLSM images and flow cytometry. So, the novel pH-sensitive nanocarrier can be applicable to carry and release both DOX drug and calcium ions for cancer treatment.


Assuntos
Cálcio , Carbono , Doxorrubicina , Portadores de Fármacos , Nanosferas , Neoplasias/tratamento farmacológico , Cálcio/química , Cálcio/farmacologia , Carbono/química , Carbono/farmacologia , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Preparações de Ação Retardada/farmacologia , Doxorrubicina/química , Doxorrubicina/farmacocinética , Doxorrubicina/farmacologia , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Portadores de Fármacos/farmacologia , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Nanosferas/química , Nanosferas/uso terapêutico , Neoplasias/metabolismo , Neoplasias/patologia , Porosidade
18.
Mikrochim Acta ; 187(4): 228, 2020 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-32170469

RESUMO

A carbon dots-embedded epitope imprinted polymer (C-MIP) was fabricated for targeted fluorescence imaging of cervical cancer by specifically recognizing the epidermal growth factor receptor (EGFR). The core-shell C-MIP was prepared by a reverse microemulsion polymerization method. This method used silica nanoparticles embedded with carbon dots as carriers, acrylamide as the main functional monomer, and N-terminal nonapeptides of EGFR modified by palmitic acid as templates. A series of characterizations (transmission electron microscope, dynamic light scattering, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, zeta potential, and energy dispersive X-ray spectroscopy) prove the successful synthesis of C-MIP. The fluorescence of C-MIP is quenched by the epitopes of EGFR due to the specific recognition of epitopes of EGFR through their imprinted cavities (analytical excitation/emission wavelengths, 540 nm/610 nm). The linear range of fluorescence quenching is 2.0 to 15.0 µg mL-1 and the determination limit is 0.73 µg mL-1. The targeted imaging capabilities of C-MIP are demonstrated through in vitro and in vivo experiments. The laser confocal imaging results indicate that HeLa cells (over-expression EGFR) incubated with C-MIP show stronger fluorescence than that of MCF-7 cells (low-expression EGFR), revealing that C-MIP can target tumor cells overexpressing EGFR. The results of imaging experiments in tumor-bearing mice exhibit that C-MIP has a better imaging effect than C-NIP, which further proves the targeted imaging ability of C-MIP in vivo. Graphical abstract An oriented epitope imprinted polymer embedded with carbon dots was prepared for the determination of the epitopes of epidermal growth factor receptor and targeted fluorescence imaging of cervical cancer.


Assuntos
Carbono/química , Receptores ErbB/análise , Impressão Molecular , Imagem Óptica , Polímeros/química , Pontos Quânticos/química , Neoplasias do Colo do Útero/diagnóstico por imagem , Carbono/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Feminino , Células HeLa , Humanos , Células MCF-7 , Estrutura Molecular , Tamanho da Partícula , Propriedades de Superfície
19.
Proc Natl Acad Sci U S A ; 117(14): 7719-7728, 2020 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-32213582

RESUMO

Chitin is the most abundant renewable nitrogenous material on earth and is accessible to humans in the form of crustacean shell waste. Such waste has been severely underutilized, resulting in both resource wastage and disposal issues. Upcycling chitin-containing waste into value-added products is an attractive solution. However, the direct conversion of crustacean shell waste-derived chitin into a wide spectrum of nitrogen-containing chemicals (NCCs) is challenging via conventional catalytic processes. To address this challenge, in this study, we developed an integrated biorefinery process to upgrade shell waste-derived chitin into two aromatic NCCs that currently cannot be synthesized from chitin via any chemical process (tyrosine and l-DOPA). The process involves a pretreatment of chitin-containing shell waste and an enzymatic/fermentative bioprocess using metabolically engineered Escherichia coli The pretreatment step achieved an almost 100% recovery and partial depolymerization of chitin from shrimp shell waste (SSW), thereby offering water-soluble chitin hydrolysates for the downstream microbial process under mild conditions. The engineered E. coli strains produced 0.91 g/L tyrosine or 0.41 g/L l-DOPA from 22.5 g/L unpurified SSW-derived chitin hydrolysates, demonstrating the feasibility of upcycling renewable chitin-containing waste into value-added NCCs via this integrated biorefinery, which bypassed the Haber-Bosch process in providing a nitrogen source.


Assuntos
Quitina/química , Nitrogênio/química , Resíduos/análise , Acetilglucosamina/metabolismo , Animais , Carbono/farmacologia , Quitosana/química , Crustáceos , Escherichia coli/genética , Engenharia Genética , Glucose/metabolismo , Hidrólise , Levodopa/metabolismo , Minerais/química , Nitrogênio/farmacologia , Polimerização , Tirosina/metabolismo
20.
Biochem Biophys Res Commun ; 525(3): 773-779, 2020 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-32147096

RESUMO

In chronic kidney disease, elevated levels of circulating uremic toxins are associated with a variety of symptoms and organ dysfunction. Indoxyl sulfate (IS) and p-cresyl sulfate (pCS) are microbiota-derived metabolites and representative uremic toxins. We have previously shown that the oral adsorbent AST-120 profoundly reduced pCS compared to IS in adenine-induced renal failure in mice. However, the mechanisms of the different attenuation effects of AST-120 between IS and pCS are unclear. To clarify the difference of AST-120 on IS and pCS, we investigated the levels of fecal indole and p-cresol, the respective precursors of IS and pCS, and examined the influence on the gut microbiota. Although fecal indole was detected in all groups analyzed, fecal p-cresol was not detected in AST-120 treatment groups. In genus level, a total of 23 organisms were significantly changed by renal failure or AST-120 treatment. Especially, AST-120 reduced the abundance of Erysipelotrichaceae uncultured and Clostridium sensu stricto 1, which have a gene involved in p-cresol production. Our findings suggest that, in addition to the adsorption of the uremic toxin precursors, AST-120 affects the abundance of some gut microbiota in normal and renal failure conditions, thereby explaining the different attenuation effects on IS and pCS.


Assuntos
Carbono/administração & dosagem , Carbono/farmacologia , Cresóis/metabolismo , Fezes/química , Microbioma Gastrointestinal/efeitos dos fármacos , Indóis/metabolismo , Óxidos/administração & dosagem , Óxidos/farmacologia , Administração Oral , Adsorção , Animais , Bactérias/efeitos dos fármacos , Falência Renal Crônica/microbiologia , Falência Renal Crônica/patologia , Masculino , Camundongos Endogâmicos C57BL
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA