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1.
Sci Total Environ ; 741: 140216, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32886998

RESUMO

About 90% of the plastic garbage remains in terrestrial ecosystems, and increasing evidence highlights the exposure of crops to plastic particles. However, the potential bioaccumulation of microplastics by plants and their effects on plants' physiology remains unexplored. Here, we evaluated the adsorption, potential uptake, and physiological effects of polyethylene (PE) microbeads in an experimental hydroponic culture of maize. Using isotope analysis, taking advantage of the different carbon isotope composition (δ13C) of fossil-derived PE and C4 plants (e.g., maize), we estimated that about 30% of the carbon in the rhizosphere of microplastic-exposed plants was derived from PE. Still, we did not find evidence of PE translocation to the shoots. Plastic bioaccumulation in the rhizosphere caused a significant decline in transpiration, nitrogen content, and growth. Our results indicate that plastic particles may accumulate in the rhizosphere, impairing water and nutrient uptake, and eventually reaching root eaters. Due to the implications for food production and livestock feeding, our findings encourage further research on the mechanism leading to the bioaccumulation of microplastics on the surface of belowground tissues.


Assuntos
Polietileno , Poluentes Químicos da Água/análise , Adsorção , Ecossistema , Hidroponia , Microesferas , Plásticos , Zea mays
2.
Chemosphere ; 258: 127384, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32947660

RESUMO

As a two-dimensional nanomaterial, bismuth oxybromide (BiOBr) have attracted tremendous interest in the area of visible-light photocatalysis since it can provide the internal electric field (IEF) through z-axis through its unique electronic band structure. However, the insufficient active sites and rapid recombination rate of charged carriers hamper the efficiency of the photocatalysis. To address these two major obstacles, an enticing strategy of constructing heterojunction was established by introducing Bi2O2(OH)(NO3) (BiON) in BiOBr with the same precursor. Through a facile one-pot hydrothermal synthesis, two Sillén-type layered photocatalysts, with intimately constructed ultrathin heterostructure, was synthesized by the co-precipitation method. In this work, the formation of Bismuth-based heterojunction for charge separation is established by the excessive bismuth nitrate, which subsequently participates with the in situ growth of ultrathin hierarchical microspheres. By attenuating the thickness of BiOBr from 20 nm to 8 nm with the aid of BiON, the photogenerated charges could migrate to the active sites through shorter charge diffusion pathway. Also, the BiOBr and BiON act as an active bridge to promote the separation of electron-hole pairs, which also brings out more active sites due to its increased specific surface area. BiON/BiOBr ultrathin hierarchical microspheres exhibited enhanced visible-light photocatalytic activity for decontaminating several types of pollutants. Besides, the activity of as-prepared BiON/BiOBr was further evaluated by inhibiting the growth of kanamycin-resistant bacteria strains. This study presents a novel strategy to incorporate the crystalline bismuth hydrate nitrate into BiOBr to form ultrathin hierarchical microspheres with high surface area for environmental remediation.


Assuntos
Recuperação e Remediação Ambiental , Microesferas , Bismuto/química , Catálise , Luz , Nitratos/química
3.
Int J Mol Sci ; 21(18)2020 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-32916926

RESUMO

Currently available COVID-19 antibody tests using enzyme immunoassay (EIA) or immunochromatographic assay have variable sensitivity and specificity. Here, we developed and evaluated a novel microsphere-based antibody assay (MBA) for detecting immunoglobulin G (IgG) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleoprotein (NP) and spike protein receptor binding domain (RBD). The seropositive cutoff value was set using a cohort of 294 anonymous serum specimens collected in 2018. The specificity was assessed using serum specimens collected from organ donors or influenza patients before 2020. Seropositive rate was determined among COVID-19 patients. Time-to-seropositivity and signal-to-cutoff (S/CO) ratio were compared between MBA and EIA. MBA had a specificity of 100% (93/93; 95% confidence interval (CI), 96-100%) for anti-NP IgG, 98.9% (92/93; 95% CI 94.2-100%) for anti-RBD IgG. The MBA seropositive rate for convalescent COVID-19 patients was 89.8% (35/39) for anti-NP IgG and 79.5% (31/39) for anti-RBD IgG. The time-to-seropositivity was shorter with MBA than EIA. MBA could better differentiate between COVID-19 patients and negative controls with higher S/CO ratio for COVID-19 patients, lower S/CO ratio with negative controls and fewer specimens in the equivocal range. MBA is robust, simple and is suitable for clinical microbiology laboratory for the accurate determination of anti-SARS-CoV-2 antibodies for diagnosis, serosurveillance, and vaccine trials.


Assuntos
Anticorpos Antivirais/sangue , Infecções por Coronavirus/sangue , Proteínas do Nucleocapsídeo/imunologia , Pneumonia Viral/sangue , Testes Sorológicos/métodos , Glicoproteína da Espícula de Coronavírus/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antivirais/imunologia , Criança , Pré-Escolar , Infecções por Coronavirus/diagnóstico , Feminino , Humanos , Lactente , Masculino , Microesferas , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/diagnóstico , Sensibilidade e Especificidade , Testes Sorológicos/normas
4.
Nat Commun ; 11(1): 4450, 2020 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-32895379

RESUMO

Hollow multishelled structures (HoMSs), with relatively isolated cavities and hierarchal pores in the shells, are structurally similar to cells. Functionally inspired by the different transmission forms in living cells, we studied the mass transport process in HoMSs in detail. In the present work, after introducing the antibacterial agent methylisothiazolinone (MIT) as model molecules into HoMSs, we discover three sequential release stages, i.e., burst release, sustained release and stimulus-responsive release, in one system. The triple-shelled structure can provide a long sterility period in a bacteria-rich environment that is nearly 8 times longer than that of the pure antimicrobial agent under the same conditions. More importantly, the HoMS system provides a smart responsive release mechanism that can be triggered by environmental changes. All these advantages could be attributed to chemical diffusion- and physical barrier-driven temporally-spatially ordered drug release, providing a route for the design of intelligent nanomaterials.


Assuntos
Antibacterianos/administração & dosagem , Preparações de Ação Retardada/administração & dosagem , Portadores de Fármacos/química , Nanoestruturas/química , Antibacterianos/farmacocinética , Preparações de Ação Retardada/farmacocinética , Difusão , Composição de Medicamentos/métodos , Liberação Controlada de Fármacos , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Microesferas , Tiazóis/administração & dosagem , Tiazóis/farmacocinética
5.
Chemosphere ; 254: 126903, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957296

RESUMO

We used discarded oyster shells to prepare vaterite calcium carbonate microparticles and explored the removal effects and the underlying mechanism toward several heavy metal ions. The removal efficiency for each ion type was: Pb2+ (99.9%), Cr3+ (99.5%), Fe3+ (99.3%), and Cu2+ (57.1%). With the exception of Cu2+, vaterite calcium carbonate particles exhibited excellent removal performance on all tested heavy metal ions, with exceptional results for Pb2+. The factor affecting the removal efficiency of heavy metal ions is shown to involve an ion exchange reaction between calcium and the heavy metal ions resulting in recrystallization. Vaterite calcium carbonate particles prepared by this method have the advantage of low price, easy synthesis, and reduction of environmental waste. Thus, this procedure for synthesizing vaterite CaCO3 provides an environmentally responsible method for preparing materials that can be economically incorporated into common consumer products such as household drinking water filtration systems.


Assuntos
Exoesqueleto/química , Carbonato de Cálcio/química , Metais Pesados/análise , Ostreidae , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Animais , Concentração de Íons de Hidrogênio , Troca Iônica , Íons , Microesferas , Propriedades de Superfície
6.
Medicine (Baltimore) ; 99(31): e20878, 2020 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-32756080

RESUMO

This case series aimed to preliminarily evaluate the efficacy and safety of drug-eluting beads transarterial chemoembolization (DEB-TACE) in patients with lung, renal, gastric, and other non-liver cancers.Twenty-four patients who underwent DEB-TACE or DEB-TACE combined with other therapies were reviewed in this case series. Treatment responses were assessed at 1 month after treatment according to the modified Response Evaluation Criteria in Solid Tumors. Overall survival (OS) and adverse events were recorded.In the total patients, the objective response and disease control rate were 79.2% and 87.5%, respectively. And the mean OS in total patients was 14.7 months (95% confidence interval: 9.6-19.9 months). The number of patients who had generalized aches, nausea, vomit, fever, abdominal discomfort, chest discomfort, elevated blood pressure, cough, loss of appetite, and headache in total patients were 7 (29.2%), 11 (45.8%), 6 (25.0%), 2 (8.3%), 3 (12.5%), 3 (12.5%), 1 (4.2%), 1 (4.2%), 1 (4.2%), and 1 (4.2%), respectively. The objective response rates in patients with lung, renal, gastric, and other non-liver cancer were 70.0%, 85.7%, 100.0%, and 80.0%, respectively. In patients with lung, renal, gastric, and other non-liver cancers, the mean values of the OSs were 13.4 months, 12.4 months, 7.6 months, and 20.3 months, respectively. And the most common adverse events in lung cancer patients, renal carcinoma patients, gastric cancer patients, and patients with other non-liver cancers were post-embolization syndrome.DEB-TACE may be an effective and safe therapeutic option in patients with lung, renal, gastric, and other non-liver cancers.


Assuntos
Quimioembolização Terapêutica/métodos , Neoplasias/terapia , Idoso , Quimioembolização Terapêutica/efeitos adversos , Feminino , Humanos , Neoplasias Renais/mortalidade , Neoplasias Renais/terapia , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/terapia , Masculino , Microesferas , Pessoa de Meia-Idade , Neoplasias/mortalidade , Critérios de Avaliação de Resposta em Tumores Sólidos , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/terapia , Análise de Sobrevida
7.
Int J Nanomedicine ; 15: 4959-4967, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32764929

RESUMO

Background: Particle-based drug delivery systems (DDSs) have a demonstrated value for drug discovery and development. However, some problems remain to be solved, such as limited stimuli, visual-monitoring. Aim: To develop an intelligent multicolor DDSs with both near-infrared (NIR) controlled release and macroscopic color changes. Materials and Methods: Microparticles comprising GO/pNIPAM/PEGDA composite hydrogel inverse opal scaffolds, with dextran and calcium alginate hydrogel were synthesized using SCCBs as the template. The morphology of microparticle was observed under scanning electron microscopy, and FITC-dextran-derived green fluorescence images were determined using a confocal laser scanning microscope. During the drug release, FITC-dextran-derived green fluorescence images were captured using fluorescent inverted microscope. The relationship between the power of NIR and the drug release rate was obtained using the change in optical density (OD) values. Finally, the amount of drug released could be estimated quantitatively used the structural color or the reflection peak position. Results: A fixed concentration 8% (v/v) of PEGDA and 4mg/mL of GO was chosen as the optimal concentration based on the balance between appropriate volume shrinkage and structure color. The FITC-dextran was uniformly encapsulated in the particles by using 0.2 wt% sodium alginate. The microcarriers shrank because of the photothermal response and the intrinsic fluorescence intensity of FITC-dextran in the microparticles gradually decreased at the same time, indicating drug release. With an increasing duration of NIR irradiation, the microparticles gradually shrank, the reflection peak shifted toward blue and the structural color changed from red to orange, yellow, green, cyan, and blue successively. The drug release quantity can be predicted by the structural color of microparticles. Conclusion: The multicolor microparticles have great potential in drug delivery systems because of its vivid reporting color, excellent photothermal effect, and the good stimuli responsivity.


Assuntos
Portadores de Fármacos/química , Microesferas , Resinas Acrílicas/química , Alginatos/química , Cor , Dextranos/química , Liberação Controlada de Fármacos , Fluoresceína-5-Isotiocianato/análogos & derivados , Fluoresceína-5-Isotiocianato/química , Hidrogéis/química , Fenômenos Ópticos , Polietilenoglicóis/química
8.
J Chromatogr A ; 1626: 461379, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797854

RESUMO

Ordered porous materials are attracting enormous attention due to their uniform pore structures, particularly the magnetic photonic crystal microspheres (PCMs) which not only possess unique photonic crystal structure but also can achieve separation easily based on magnet. Here, a two-phase microfluidic self-assembly synthetic system was established simply and employed for the preparation of three dimensional PCMs (3DPCMs) by using the emulsion droplet approach. One phase (dispersed phase) was an aqueous emulsion containing Fe3O4, silica (SiO2) and polystyrene (PS) nanoparticles; another phase (continuous phase) was pure silicone oil. The droplets were formed by introducing the dispersed phase into the continuous phase through a tee valve. By heating the droplets, the water would evaporate and the nanoparticles would finally assemble into solid microspheres, which could be changed into macroporous 3DPCMs after removal of the PS nanoparticles by calcination. The contents and particle sizes of Fe3O4, SiO2 and PS nanoparticles in the dispersed phase were investigated in detail and optimized to prepare macroporous magnetic 3DPCMs with high quality. The morphologies, surface crystal structure, magnetic property, particle size distribution, specific surface area and pore size of the macroporous magnetic 3DPCMs were characterized. The expected 3DPCM displayed regular and uniform photonic crystal structure, narrow particle size distribution and strong magnetic property. The macroporous magnetic 3DPCMs grafted with vomitoxin (DON)-antibodies could be applied for selective enrichment of DON in real samples.


Assuntos
Magnetismo , Microfluídica/métodos , Microesferas , Tricotecenos/análise , Anticorpos/imunologia , Cromatografia Líquida de Alta Pressão , Óxido Ferroso-Férrico/química , Contaminação de Alimentos/análise , Nanopartículas/química , Tamanho da Partícula , Poliestirenos/química , Porosidade , Dióxido de Silício/química , Espectrofotometria , Tricotecenos/imunologia
9.
J Chromatogr A ; 1627: 461422, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823117

RESUMO

Sialylation, an important form of glycosylation, is involved in many biological processes and plays an important role in the development of diseases. However, due to the low abundance among various glycosylation and lack of efficient enrichment method with high specificity, the study of sialylation remains a challenge. Herein, multi-histidine modified microspheres (MHM) were synthesized to enrich sialylated glycopeptides. It was found that MHM could selectively enrich sialylated glycopeptides from over 100 times of non-sialylated glycopeptides, which indicated MHM possessed good enrichment specificity towards sialylated glycopeptides. Furthermore, MHM were utilized to the large-scale analysis of protein sialylation, and 510 intact glycopeptides were identified with over 94.5% sialylated glycopeptide specificity from 4 µL human serum. The good specificity could be attributed to the synergistic effect by the electrostatic interaction and hydrophilic interaction. Hence, MHM could provide an alternative approach for the analysis of site-specific sialylation at proteome level from complex biological samples.


Assuntos
Glicopeptídeos/análise , Histidina/química , Ácido N-Acetilneuramínico/química , Sequência de Aminoácidos , Avidina/química , Fetuínas/química , Glicopeptídeos/sangue , Glicosilação , Humanos , Microesferas , Padrões de Referência , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
10.
J Chromatogr A ; 1626: 461348, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797828

RESUMO

Solid-phase extraction (SPE) is a widely-used and very well-established sample preparation technique for liquid samples. An area of on-going focus for innovation in this field concerns the development of new and improved SPE sorbents that can enhance the sensitivity and/or the selectivity of SPE processes. In this context, mixed-mode ion-exchange sorbents have been developed and commercialised, thereby allowing enhanced capacity and selectivity to be offered by one single material. The ion-selectivity of these materials is such that either anion-exchange or cation-exchange is possible, however one limitation to their use is that more than one sorbent type is required to capture both anions and cations. In this paper, we disclose the design, synthesis and exploitation of a novel SPE sorbent based on microporous polymer microspheres with amphoteric character. We show that it is possible to switch the ion-exchange retention mechanism of the sorbent simply by changing the pH of the loading solution; anion-exchange dominates at low pH, cation-exchange dominates at high pH, and both mechanisms can contribute to retention when the polymer-bound amphoteric species, which are based on the α-amino acid sarcosine (N-methylglycine), are in a zwitterionic state. This is an interesting and useful feature, since it allows distinctly different groups of analytes (acids and bases) to be fractionated using one single amphoteric sorbent with dual-functionality. The sarcosine-based sorbent was applied to the SPE of acidic, basic and amphoteric analytes from ultrapure water, river water and effluent wastewater samples. Under optimised conditions (loading 100 mL of sample at pH 6, washing with 1 mL of MeOH and eluting with an acidic or basic additive in MeOH) the recoveries for most of the compounds were from 57% to 87% for river water and from 61% to 88% for effluent wastewater. We anticipate that these results will lay the basis for the development of a new family of multifunctional sorbents, where two or more separation mechanisms can be embedded within one single, bespoke material optimised for application to challenging chemical separations to give significant selectivity advantages over essentially all other state-of-the-art SPE sorbents.


Assuntos
Ácidos/química , Microesferas , Polímeros/química , Extração em Fase Sólida/métodos , Adsorção , Cátions , Concentração de Íons de Hidrogênio , Troca Iônica , Porosidade , Rios/química , Solventes/química , Águas Residuárias/química , Poluentes Químicos da Água/análise
11.
Nat Protoc ; 15(9): 2773-2784, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32737465

RESUMO

Spherical aberration (SA) occurs when light rays entering at different points of a spherical lens are not focused to the same point of the optical axis. SA that occurs inside the lens elements of a fluorescence microscope is well understood and corrected for. However, SA is also induced when light passes through an interface of refractive index (RI)-mismatched substances (i.e., a discrepancy between the RI of the immersion medium and the RI of the sample). SA due to RI mismatches has many deleterious effects on imaging. Perhaps most important for 3D imaging is that the distance the image plane moves in a sample is not equivalent to the distance traveled by an objective (or stage) during z-stack acquisition. This non-uniform translation along the z axis gives rise to artifactually elongated images (if the objective is immersed in a medium with a higher RI than that of the sample) or compressed images (if the objective is immersed in a medium with a lower RI than that of the sample) and alters the optimal axial sampling rate. In this tutorial, we describe why this distortion occurs, how it impacts quantitative measurements and axial resolution, and what can be done to avoid SA and thereby prevent distorted images. In addition, this tutorial aims to better inform researchers of how to correct RI mismatch-induced axial distortions and provides a practical ImageJ/Fiji-based tool to reduce the prevalence of volumetric measurement errors and lost axial resolution.


Assuntos
Artefatos , Imageamento Tridimensional , Microscopia de Fluorescência , Espalhamento de Radiação , Corantes Fluorescentes/química , Microesferas
12.
Cochrane Database Syst Rev ; 8: CD008227, 2020 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-32761612

RESUMO

BACKGROUND: Most people with cystic fibrosis (CF) (80% to 90%) need pancreatic enzyme replacement therapy (PERT) to prevent malnutrition. Enzyme preparations need to be taken whenever food is taken, and the dose needs to be adjusted according to the food consumed. A systematic review on the efficacy and safety of PERT is needed to guide clinical practice, as there is variability between centres with respect to assessment of pancreatic function, time of commencing treatment, dose and choice of supplements. This is an updated version of a published review. OBJECTIVES: To evaluate the efficacy and safety of PERT in children and adults with CF and to compare the efficacy and safety of different formulations of PERT and their appropriateness in different age groups. Also, to compare the effects of PERT in CF according to different diagnostic subgroups (e.g. different ages at introduction of therapy and different categories of pancreatic function). SEARCH METHODS: We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. Most recent search: 07 November 2019. We also searched an ongoing trials website and the websites of the pharmaceutical companies who manufacture pancreatic enzyme replacements for any additional trials. Most recent search: 26 December 2019. SELECTION CRITERIA: Randomised and quasi-randomised controlled trials in people of any age, with CF and receiving PERT, at any dosage and in any formulation, for a period of not less than four weeks, compared to placebo or other PERT preparations. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trials and extracted outcome data. They also assessed the risk of bias and quality of the evidence (GRADE) of the trials included in the review. MAIN RESULTS: 14 trials were included in the review (641 children and adults with CF), two of these were parallel trials and 12 were cross-over trials. Interventions included different enteric and non-enteric-coated preparations of varying formulations in comparison to each other. The number of participants in each trial varied between 14 and 129. 13 trials were for a duration of four weeks and one trial lasted seven weeks. The majority of the trials had an unclear risk of bias from the randomisation process as the details of this were not given; they also had a high risk of attrition bias and reporting bias. The quality of the evidence ranged from moderate to very low. We mostly could not combine data from the trials as they compared different formulations and the findings from individual trials provided insufficient evidence to determine the size and precision of the effects of different formulations. AUTHORS' CONCLUSIONS: There is limited evidence of benefit from enteric-coated microspheres when compared to non-enteric coated pancreatic enzyme preparations up to one month. In the only comparison where we could combine any data, the fact that these were cross-over trials is likely to underestimate the level of inconsistency between the results of the trials due to over-inflation of CIs from the individual trials.There is no evidence on the long-term effectiveness and risks associated with PERT. There is also no evidence on the relative dosages of enzymes needed for people with different levels of severity of pancreatic insufficiency, optimum time to start treatment and variations based on differences in meals and meal sizes. There is a need for a properly designed trial that can answer these questions.


Assuntos
Fibrose Cística/terapia , Terapia de Reposição de Enzimas/normas , Dor Abdominal/epidemiologia , Adulto , Fatores Etários , Cápsulas/administração & dosagem , Criança , Preparações de Ação Retardada , Terapia de Reposição de Enzimas/efeitos adversos , Fármacos Gastrointestinais/uso terapêutico , Humanos , Microesferas , Estado Nutricional , Pâncreas/enzimologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Ganho de Peso
13.
J Chromatogr A ; 1627: 461378, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823092

RESUMO

Downstream processing (DSP) of large bionanoparticles is still a challenge. The present study aims to systematically compare some of the most commonly used DSP strategies for capture and purification of enveloped viruses and virus-like particles (eVLPs) by using the same staring material and analytical tools. As a model, Human Immunodeficiency Virus-1 (HIV-1) gag VLPs produced in CHO cells were used. Four different DSP strategies were tested. An anion-exchange monolith and a membrane adsorber, for direct capture and purification of eVLPs, and a polymer-grafted anion-exchange resin and a heparin-affinity resin for eVLP purification after a first flow-through step to remove small impurities. All tested strategies were suitable for capture and purification of eVLPs. The performance of the different strategies was evaluated regarding its binding capacity, ability to separate different particle populations and product purity. The highest binding capacity regarding total particles was obtained using the anion exchange membrane adsorber (5.3 × 1012 part/mL membrane), however this method did not allow the separation of different particle populations. Despite having a lower binding capacity (1.5 × 1011 part/mL column) and requiring a pre-processing step with flow-through chromatography, Heparin-affinity chromatography showed the best performance regarding separation of different particle populations, allowing not only the separation of HIV-1 gag VLPs from host cell derived bionanoparticles but also from chromatin. This work additionally shows the importance of thorough sample characterization combining several biochemical and biophysical methods in eVLP DSP.


Assuntos
Convecção , HIV-1/isolamento & purificação , Adsorção , Animais , Ânions , Células CHO , Cromatina/metabolismo , Cromatografia de Afinidade , Cricetinae , Cricetulus , HIV-1/ultraestrutura , Histonas/metabolismo , Humanos , Microesferas , Nanopartículas/química , Nanopartículas/ultraestrutura , Polímeros/química , Porosidade , Vírion/isolamento & purificação , Vírion/ultraestrutura
14.
Int J Nanomedicine ; 15: 4105-4123, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32606667

RESUMO

Background: Magnetic nanoparticles (MNPs) hold promise for enhancing delivery of therapeutic agents, either through direct binding or by functioning as miniature propellers. Fluid-filled conduits and reservoirs within the body offer avenues for MNP-enhanced drug delivery. MNP clusters can be rotated and moved across surfaces at clinically relevant distances in response to a rotating magnet. Limited data are available regarding issues affecting MNP delivery by this mechanism, such as adhesion to a cellular wall. Research reported here was initiated to better understand the fundamental principles important for successful implementation of rotational magnetic drug targeting (rMDT). Methods: Translational movements of four different iron oxide MNPs were tested, in response to rotation (3 Hz) of a neodymium-boron-iron permanent magnet. MNP clusters moved along biomimetic channels of a custom-made acrylic tray, by surface walking. The effects of different distances and cellular coatings on MNP velocity were analyzed using videography. Dyes (as drug surrogates) and the drug etoposide were transported by rotating MNPs along channels over a 10 cm distance. Results: MNP translational velocities could be predicted from magnetic separation times. Changes in distance or orientation from the magnet produced alterations in MNP velocities. Mean velocities of the fastest MNPs over HeLa, U251, U87, and E297 cells were 0.24 ± 0.02, 0.26 ± 0.02, 0.28 ± 0.01, and 0.18 ± 0.03 cm/sec, respectively. U138 cells showed marked MNP adherence and an 87.1% velocity reduction at 5.5 cm along the channel. Dye delivery helped visualize the effects of MNPs as microdevices for drug delivery. Dye delivery by MNP clusters was 21.7 times faster than by diffusion. MNPs successfully accelerated etoposide delivery, with retention of chemotherapeutic effect. Conclusion: The in vitro system described here facilitates side-by-side comparisons of drug delivery by rotating MNP clusters, on a human scale. Such microdevices have the potential for augmenting drug delivery in a variety of clinical settings, as proposed.


Assuntos
Sistemas de Liberação de Medicamentos/instrumentação , Nanopartículas de Magnetita/química , Microtecnologia/instrumentação , Rotação , Transporte Biológico , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Difusão , Etoposídeo/farmacologia , Humanos , Microesferas , Tamanho da Partícula , Tomografia Computadorizada por Raios X
15.
ACS Sens ; 5(8): 2331-2337, 2020 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-32660240

RESUMO

The SARS-CoV-2 infection that caused the COVID-19 pandemic quickly spread worldwide within two months. Rapid diagnosis of the disease and isolation of patients are effective ways to prevent and control the spread of COVID-19. Therefore, a sensitive immunofluorescent assay method was developed for rapid detection of special IgM and IgG of COVID-19 in human serum within 10 min. The recombinant nucleocapsid protein of 2019 novel coronavirus was used as capture antigen. Lanthanide, Eu(III) fluorescent microsphere, was used to qualitatively/semiquantitatively determine the solid phase immunochromatographic assay. A total of 28 clinical positive and 77 negative serum or plasma samples were included in the test. Based on the analysis of serum or plasma from COVID-19 patients and healthy people, the sensitivity and specificity of the immunochromatographic assay were calculated as 98.72% and 100% (IgG), and 98.68% and 93.10% (IgM), respectively. The results demonstrated that rapid immunoassay has high sensitivity and specificity and was useful for rapid serodiagnosis of COVID-19.


Assuntos
Infecções por Coronavirus/diagnóstico , Imunoensaio/métodos , Microesferas , Pneumonia Viral/diagnóstico , Testes Sorológicos/métodos , Európio , Fluorescência , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Elementos da Série dos Lantanídeos , Proteínas do Nucleocapsídeo/imunologia , Pandemias , Sensibilidade e Especificidade , Testes Sorológicos/normas , Fatores de Tempo
16.
Environ Sci Pollut Res Int ; 27(30): 38334-38343, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32623669

RESUMO

A facile method to synthesize adsorbent based on cellulose modified by amino acid was developed. The novel L-cysteine-functionalized adsorbent for Au(III) recovery was synthesized via radiation grafting technique. Glycidyl methacrylate (GMA) was grafted on the surface of microcrystalline cellulose microsphere (MCC); next, ring-opening reaction was performed to immobilize L-cysteine. The adsorption abilities of the adsorbent (CysR) were tested. Batch experiments suggested that the maximum adsorption capacity of Au(III) is 714.28 mg/g calculated by Langmuir model. The adsorption kinetic data was followed by pseudo-second-order model. CysR showed excellent selectivity for Au(III) even the concentration of competing ions was all ten times than that of Au(III). The column experiments revealed that Au(III) could be efficiently adsorbed by CysR competition with equal amounts of Ni(II) and Zn(II). Moreover, XPS analysis demonstrated that the adsorbed Au(III) was reduced to Au(I) and Au(0). The adsorption performance certified that CysR was a promising adsorbent for Au(III) recovery.


Assuntos
Cisteína , Poluentes Químicos da Água , Adsorção , Celulose , Cinética , Microesferas
17.
Water Res ; 183: 116095, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32645579

RESUMO

Photocatalytic water treatment has significant potential to disinfect and degrade recalcitrant organic pollutants while minimizing the need to add chemicals, but current approaches have poor energy efficiency due, in part, to inefficient utilization of photo-generated reactive oxygen species (ROS). Organic coatings such as cyclodextrin (CD) can adsorb target contaminants and bring them close to the photocatalyst surface to enhance ROS utilization efficiency, but the coatings themselves are susceptible to ROS attack. Here, we report an ROS-resistant fluorinated CD polymer (CDP) that can both adsorb contaminants and resist degradation by ROS, yielding a more efficient material for "trap and zap" water treatment. We produced the CDP through condensation polymerization of ß-cyclodextrin and tetrafluoroterephthalonitrile, resulting in a cross-linked, covalently bound CD film that is much more stable than prior approaches involving physi-sorption. We optimized the coating thickness on TiO2 microspheres to improve the efficiency of contaminant degradation, and found that increasing the CDP content enhanced BPA adsorption but also occluded photocatalytic sites and hindered photocatalytic degradation. The optimum content of CDP was 5% by weight, and this optimal CDP-TiO2 composition had a BPA adsorption capacity of 36.9 ± 1.0 mg g-1 compared with 24.1 ± 1.1 mg g-1 for CD-coated TiO2 (CD-TiO2) and 21.9 ± 1.5 mg g-1 for bare TiO2. CDP-TiO2 exhibited minimal photoactivity loss after 1000 h of repeated use in DI water under UVA irradiation (365 nm, 3.83 × 10-6 E L-1s-1), and no release of organic carbon from the coating was detected. Photocatalytic treatment using CDP-TiO2 only showed a small decrease in BPA removal efficiency in secondary effluent after four 3-h cycles, from 80.2% to 71.7%. In contrast, CD-TiO2 and P25 removed only 29.8% and 6.2% of BPA after 4 cycles, respectively. Altogether, the CDP-TiO2 microspheres represent promising materials for potential use in photocatalytic water treatment.


Assuntos
Ciclodextrinas , Titânio , Compostos Benzidrílicos , Catálise , Microesferas , Fenóis
18.
J Cancer Res Clin Oncol ; 146(10): 2575-2587, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32715436

RESUMO

BACKGROUND: Limited treatment options are available in chemotherapy-refractory metastatic colorectal cancer (mCRC). The objective was to conduct a systematic literature review (SLR) and exploratory network meta-analysis (NMA) to compare the tolerability and effectiveness of SIRT with Y-90 resin microspheres, regorafenib, TAS-102 (trifluridine/tipiracil), and best supportive care (BSC) as third-line treatment in patients with mCRC. METHODS: An SLR was conducted to identify studies comparing two or more of the treatments and reporting overall survival (OS), progression-free survival, tumor response, or adverse event (AE) incidence. An exploratory NMA was conducted to compare hazard ratios (HRs) for OS using Markov chain Monte Carlo (MCMC) techniques. RESULTS: Seven studies were identified in the SLR: two double-blind randomized-controlled trials (RCT) for each drug, one open-label RCT, and two non-randomized comparative studies for SIRT. Patient selection criteria differed between studies, with SIRT studies including patients with liver-dominant colorectal metastases. Nausea and vomiting were more frequent with TAS-102 than regorafenib or SIRT; diarrhea was more common with TAS-102 and regorafenib than SIRT. The exploratory NMA suggested that all active treatments improved OS, with HRs of 0.48 (95% CrI 0.30-0.78) for SIRT with Y-90 resin microspheres, 0.63 (0.38-1.03) for TAS-102, and 0.67 (0.40-1.08) for regorafenib each compared to BSC. CONCLUSIONS: Regorafenib, TAS-102 and SIRT using Y-90 resin microspheres are more effective than BSC in third-line treatment of mCRC; however, study heterogeneity made comparisons between active treatments challenging. SIRT is a viable treatment for third-line mCRC and its favorable AE profile should be considered in the therapeutic decision-making process.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Braquiterapia/métodos , Neoplasias Colorretais/dietoterapia , Neoplasias Colorretais/radioterapia , Compostos de Fenilureia/uso terapêutico , Piridinas/uso terapêutico , Pirrolidinas/uso terapêutico , Trifluridina/uso terapêutico , Uracila/análogos & derivados , Radioisótopos de Ítrio/administração & dosagem , Método Duplo-Cego , Combinação de Medicamentos , Humanos , Microesferas , Metástase Neoplásica , Metanálise em Rede , Cuidados Paliativos/métodos , Compostos de Fenilureia/administração & dosagem , Intervalo Livre de Progressão , Piridinas/administração & dosagem , Pirrolidinas/administração & dosagem , Ensaios Clínicos Controlados Aleatórios como Assunto , Trifluridina/administração & dosagem , Uracila/administração & dosagem , Uracila/uso terapêutico
19.
J Chromatogr A ; 1625: 461276, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709328

RESUMO

The monodisperse pillar[5]arene-based polymeric sub-microsphere was prepared by polycondensation of hydroxylated pillar[5]arene and cyanuric chloride through a one-pot reaction in mild condition. The preparation was realized by a simple two-step temperature-programmed process without heating operation. The obtained polymeric sub-microsphere exhibited monodisperse and regular spherical structure with uniform particle size distribution of 220-320 nm accounting for 94%. The prominent adsorption capacity of the polymeric sub-microsphere for antioxidants was demonstrated and attributed to the synergistic effect of the cladding interaction with the π-electron rich cavity and hydrophilic interaction with terminal hydroxyl on pillar[5]arene. Then the pillar[5]arene sub-microsphere was packed into a micro-column to realize effective on-line enrichment of antioxidants coupling with high-performance liquid chromatography (HPLC). The flow rate of extraction and desorption solvent, clean-up and desorption volume were assessed to optimize the method. The method showed wide linear ranges with R2 greater than 0.9926, low limits of detection (0.030-0.20 µg/L) and limits of quantification (0.10-0.67 µg/L). The developed method was successfully applied to determine trace antioxidants in the migration of food contact materials with simulated solution, which demonstrated the promising potential of this method for practical analysis. Furthermore, the migration behavior of antioxidants from food packaging materials into different food matrix was also investigated.


Assuntos
Antioxidantes/análise , Calixarenos/química , Cromatografia Líquida de Alta Pressão/métodos , Embalagem de Alimentos , Microesferas , Sistemas On-Line , Polímeros/química , Adsorção , Bebidas/análise , Interações Hidrofóbicas e Hidrofílicas , Tamanho da Partícula , Reprodutibilidade dos Testes , Solventes
20.
J Chromatogr A ; 1625: 461282, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709333

RESUMO

In recent years, core-shell silica particles (CSSPs) have been increasingly used for highly efficient separation at fast flow rates and relatively low back pressures in high-performance liquid chromatography (HPLC). However, material synthesis techniques for producing CSSPs economically in batch processes remain elusive. In this report, a practical and straightforward method for the preparation of CSSPs is presented. By refluxing freshly prepared nonporous silica particles in ammonia-water solution in the presence of poly(diallyldimethylammonium chloride) at 70-100 °C, CSSPs with shell thicknesses of up to 300 nm and pore sizes from 8 to 25 nm were easily prepared. The effects of the synthetic conditions on the shell thickness, surface area, and pore size were investigated in detail, and the method reproducibility was evaluated in scale-up experiments. A mechanism of CSSP formation is also proposed. The CSSPs were characterized via scanning electron microscopy, transmission electron microscopy, laser particle size (dynamic light scattering) analysis, and nitrogen adsorption and desorption experiments. The synthesized 3.4-µm CSSPs were functionalized with dimethyloctadecylchlorosilane and used as an HPLC packing material, exhibiting excellent separation performance for both small molecules and large biomolecules. In summary, we report the simplest method developed thus far for the preparation of monodisperse core-shell silica particles suitable for HPLC column packing.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Sílica Gel/química , Adsorção , Amônia/análise , Difusão Dinâmica da Luz , Microesferas , Peso Molecular , Nanopartículas/química , Nanopartículas/ultraestrutura , Tamanho da Partícula , Polietilenos/química , Porosidade , Compostos de Amônio Quaternário/química , Reprodutibilidade dos Testes , Temperatura , Fatores de Tempo
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