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1.
Braz Oral Res ; 34: e095, 2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32901725

RESUMO

The purpose of this study was to synthesize dicalcium phosphate dihydrate (DCPD) particles functionalized with triethylene glycol dimethacrylate (TEGDMA) through different routes by varying the receptor solution: ammonium phosphate (AP groups) or calcium nitrate (CN groups) and the moment in which TEGDMA was incorporated: ab initio (ab) or at the end of dripping the solution (ap). Two syntheses were performed without adding TEGDMA (nf). The particles were characterized by X-ray diffractometry, true density (using a helium pycnometer), surface area, and scanning electron microscopy. A 20 vol% of DCPD particles from the D, E, and F groups was added to the resin matrix to determine the degree of conversion (DC), biaxial flexural strength (BFS), the flexural modulus (FM), and surface roughness after an abrasive challenge (RA). A group with silanized barium glass particles was tested as a control. The data were submitted to ANOVA/Tukey's test (DC, BFS, and RA), and the Kruskal-Wallis test (FM) (alpha = 0.05). BFS values varied between 83 and 142 MPa, and the CN_ab group presented a similar value (123 MPa) to the control group. FM values varied between 3.6 and 8.7 GPa (CN_ab and CN_nf groups, respectively), with a significant difference found only between these groups. RA did not result in significant differences. The use of calcium nitrate solution as a receptor, together with ab initio functionalization formed particles with larger surface areas. Higher BFS values were observed for the material containing DCPD particles with a higher surface area. In general, the DC, FM, and RA values were not affected by the variables studied.


Assuntos
Polímeros/química , Resinas Compostas , Resistência à Flexão
2.
PLoS One ; 15(8): e0237271, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32866161

RESUMO

Molecular separation of pharmaceutical contaminants from water has been recently of great interest to alleviate their detrimental impacts on environment and human well-being. As the novelty, this investigation aims to develop a mechanistic modeling approach and consequently its related CFD-based simulations to evaluate the molecular separation efficiency of ibuprofen (IP) and its metabolite 4-isobutylacetophenone (4-IBAP) from water inside a porous membrane contactor (PMC). For this purpose, octanol has been applied as an organic phase to extract IP and 4-IBAP from the aqueous solution due to high solubility of solutes in octanol. Finite element (FE) technique is used as a promising tool to simultaneously solve continuity and Navier-Stokes equations and their associated boundary conditions in tube, shell and porous membrane compartments of the PMC. The results demonstrated that the application of PMC and liquid-liquid extraction process can be significantly effective due to separating 51 and 54% of inlet IP and 4-IBAP molecules from aqueous solution, respectively. Moreover, the impact of various operational / functional parameters such as packing density, the number of fibrous membrane, the module length, the membrane porosity / tortuosity, and ultimately the aqueous solution flow rate on the molecular separation efficiency of IP and 4-IBAP is studied in more details.


Assuntos
Acetofenonas/isolamento & purificação , Anti-Inflamatórios não Esteroides/isolamento & purificação , Ibuprofeno/isolamento & purificação , Membranas Artificiais , Polímeros/química , Extração Líquido-Líquido/métodos , Octanóis/química , Porosidade , Solubilidade , Soluções
3.
Nat Commun ; 11(1): 4683, 2020 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-32943621

RESUMO

Wearable dry electrodes are needed for long-term biopotential recordings but are limited by their imperfect compliance with the skin, especially during body movements and sweat secretions, resulting in high interfacial impedance and motion artifacts. Herein, we report an intrinsically conductive polymer dry electrode with excellent self-adhesiveness, stretchability, and conductivity. It shows much lower skin-contact impedance and noise in static and dynamic measurement than the current dry electrodes and standard gel electrodes, enabling to acquire high-quality electrocardiogram (ECG), electromyogram (EMG) and electroencephalogram (EEG) signals in various conditions such as dry and wet skin and during body movement. Hence, this dry electrode can be used for long-term healthcare monitoring in complex daily conditions. We further investigated the capabilities of this electrode in a clinical setting and realized its ability to detect the arrhythmia features of atrial fibrillation accurately, and quantify muscle activity during deep tendon reflex testing and contraction against resistance.


Assuntos
Condutividade Elétrica , Epiderme , Monitorização Fisiológica/instrumentação , Movimento (Física) , Pele , Artefatos , Impedância Elétrica , Eletrocardiografia/instrumentação , Eletrocardiografia/métodos , Eletrodos , Eletroencefalografia/instrumentação , Eletroencefalografia/métodos , Eletromiografia/instrumentação , Eletromiografia/métodos , Desenho de Equipamento , Humanos , Monitorização Fisiológica/métodos , Polímeros/química , Sorbitol
4.
Nat Commun ; 11(1): 4536, 2020 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-32913189

RESUMO

Natural musculoskeletal systems have been widely recognized as an advanced robotic model for designing robust yet flexible microbots. However, the development of artificial musculoskeletal systems at micro-nanoscale currently remains a big challenge, since it requires precise assembly of two or more materials of distinct properties into complex 3D micro/nanostructures. In this study, we report femtosecond laser programmed artificial musculoskeletal systems for prototyping 3D microbots, using relatively stiff SU-8 as the skeleton and pH-responsive protein (bovine serum albumin, BSA) as the smart muscle. To realize the programmable integration of the two materials into a 3D configuration, a successive on-chip two-photon polymerization (TPP) strategy that enables structuring two photosensitive materials sequentially within a predesigned configuration was proposed. As a proof-of-concept, we demonstrate a pH-responsive spider microbot and a 3D smart micro-gripper that enables controllable grabbing and releasing. Our strategy provides a universal protocol for directly printing 3D microbots composed of multiple materials.


Assuntos
Biomimética/métodos , Compostos de Epóxi/efeitos da radiação , Fenômenos Fisiológicos Musculoesqueléticos , Polímeros/efeitos da radiação , Robótica/métodos , Soroalbumina Bovina/efeitos da radiação , Biomimética/instrumentação , Compostos de Epóxi/química , Hidrogéis/química , Hidrogéis/efeitos da radiação , Concentração de Íons de Hidrogênio , Lasers , Polimerização/efeitos da radiação , Polímeros/química , Impressão Tridimensional , Robótica/instrumentação , Soroalbumina Bovina/química
5.
Nat Commun ; 11(1): 4655, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938918

RESUMO

Purely organic room-temperature phosphorescence has attracted attention for bioimaging but can be quenched in aqueous systems. Here we report a water-soluble ultralong organic room-temperature phosphorescent supramolecular polymer by combining cucurbit[n]uril (CB[7], CB[8]) and hyaluronic acid (HA) as a tumor-targeting ligand conjugated to a 4-(4-bromophenyl)pyridin-1-ium bromide (BrBP) phosphor. The result shows that CB[7] mediated pseudorotaxane polymer CB[7]/HA-BrBP changes from small spherical aggregates to a linear array, whereas complexation with CB[8] results in biaxial pseudorotaxane polymer CB[8]/HA-BrBP which transforms to relatively large aggregates. Owing to the more stable 1:2 inclusion complex between CB[8] and BrBP and the multiple hydrogen bonds, this supramolecular polymer has ultralong purely organic RTP lifetime in water up to 4.33 ms with a quantum yield of 7.58%. Benefiting from the targeting property of HA, this supramolecular polymer is successfully applied for cancer cell targeted phosphorescence imaging of mitochondria.


Assuntos
Mitocôndrias/efeitos dos fármacos , Polímeros/química , Células A549 , Células HEK293 , Humanos , Ácido Hialurônico/química , Ligação de Hidrogênio , Medições Luminescentes , Microscopia Confocal , Neoplasias/diagnóstico por imagem , Neoplasias/patologia , Polímeros/metabolismo , Taxoides/química , Temperatura
6.
Nat Commun ; 11(1): 4848, 2020 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-32973166

RESUMO

Polydopamine (PDA) is a simple and versatile conformal coating material that has been proposed for a variety of uses; however in practice its performance is often hindered by poor mechanical properties and high roughness. Here, we show that blue-diode laser annealing dramatically improves mechanical performance and reduces roughness of PDA coatings. Laser-annealed PDA (LAPDA) was shown to be >100-fold more scratch resistant than pristine PDA and even better than hard inorganic substrates, which we attribute to partial graphitization and covalent coupling between PDA subunits during annealing. Moreover, laser annealing provides these benefits while preserving other attractive properties of PDA, as demonstrated by the superior biofouling resistance of antifouling polymer-grafted LAPDA compared to PDA modified with the same polymer. Our work suggests that laser annealing may allow the use of PDA in mechanically demanding applications previously considered inaccessible, without sacrificing the functional versatility that is so characteristic of PDA.


Assuntos
Indóis/química , Indóis/efeitos da radiação , Lasers , Polímeros/química , Polímeros/efeitos da radiação , Incrustação Biológica , Materiais Revestidos Biocompatíveis/química , Teste de Materiais , Propriedades de Superfície
7.
J Chromatogr A ; 1628: 461444, 2020 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-32822983

RESUMO

The effect of bead and ligand structure on protein adsorption was investigated for multimodal anion exchangers combining a quaternary ammonium ion group with hydrophobic moieties: Nuvia aPrime 1 and aPrime 2, based on a 54 µm diameter polymeric bead, and Capto Adhere ImpRes and Capto Adhere, based on agarose beads 51 and 78 µm diameter, respectively. Bovine serum albumin (BSA) monomer, BSA dimer, and thyroglobulin (Tg) were used as model proteins. Based on TEM imaging and iSEC, the Nuvia resins have a microgranular structure and large pores (110 nm radius), while the Capto resins have a fibrous structure and smaller pores (32-36 nm radius). Comparable binding capacities (80-110 mg/mL), decreasing as salt is added, are observed for all three proteins on the Nuvia resins. Higher capacities (110-130 mg/mL), also decreasing as salt is added, are observed for BSA monomer and dimer on the Capto resins. However, the Tg binding capacity is very low in this case and increases as salt is added. Confocal laser scanning microscopy show that the kinetics are controlled by pore diffusion for all four resins, but with diffusivities that decrease as the protein size increases especially for the Capto resins. For Tg at low salt, binding is restricted to a thin shell close to the bead surface for both Capto resins. The ratio of effective and free diffusivity is about 0.30, 0.18, and 0.08 for BSA monomer, BSA dimer, and Tg, respectively, on the Nuvia resin. These values decrease to about 0.11, 0.04, and 0.01, respectively, for the Capto resins as a result of diffusional hindrance. Dynamic binding capacities are consistent with the equilibrium and rate behaviors.


Assuntos
Resinas de Troca de Ânions/química , Cromatografia por Troca Iônica , Proteínas/metabolismo , Adsorção , Ânions/química , Difusão , Interações Hidrofóbicas e Hidrofílicas , Cinética , Ligantes , Polímeros/química , Sefarose/química , Soroalbumina Bovina/química
8.
Nat Commun ; 11(1): 4195, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32826916

RESUMO

Realizing a clinical-grade electronic medicine for peripheral nerve disorders is challenging owing to the lack of rational material design that mimics the dynamic mechanical nature of peripheral nerves. Electronic medicine should be soft and stretchable, to feasibly allow autonomous mechanical nerve adaptation. Herein, we report a new type of neural interface platform, an adaptive self-healing electronic epineurium (A-SEE), which can form compressive stress-free and strain-insensitive electronics-nerve interfaces and enable facile biofluid-resistant self-locking owing to dynamic stress relaxation and water-proof self-bonding properties of intrinsically stretchable and self-healable insulating/conducting materials, respectively. Specifically, the A-SEE does not need to be sutured or glued when implanted, thereby significantly reducing complexity and the operation time of microneurosurgery. In addition, the autonomous mechanical adaptability of the A-SEE to peripheral nerves can significantly reduce the mechanical mismatch at electronics-nerve interfaces, which minimizes nerve compression-induced immune responses and device failure. Though a small amount of Ag leaked from the A-SEE is observed in vivo (17.03 ppm after 32 weeks of implantation), we successfully achieved a bidirectional neural signal recording and stimulation in a rat sciatic nerve model for 14 weeks. In view of our materials strategy and in vivo feasibility, the mechanically adaptive self-healing neural interface would be considered a new implantable platform for a wide range application of electronic medicine for neurological disorders in the human nervous system.


Assuntos
Eletrônica Médica/instrumentação , Eletrônica Médica/métodos , Neurocirurgia/instrumentação , Neurocirurgia/métodos , Nervos Periféricos/fisiologia , Animais , Engenharia Biomédica/instrumentação , Engenharia Biomédica/métodos , Sistema Nervoso Central/fisiologia , Sistema Nervoso Central/cirurgia , Ouro , Humanos , Masculino , Teste de Materiais , Modelos Animais , Tecido Nervoso/patologia , Tecido Nervoso/cirurgia , Nervos Periféricos/patologia , Nervos Periféricos/cirurgia , Polímeros/química , Próteses e Implantes , Ratos , Nervo Isquiático , Dispositivos Eletrônicos Vestíveis
9.
Nat Commun ; 11(1): 4193, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32826921

RESUMO

Photochemical reactions are a powerful tool in (bio)materials design due to the spatial and temporal control light can provide. To extend their applications in biological setting, the use of low-energy, long wavelength light with high penetration propertiesis required. Further regulation of the photochemical process by additional stimuli, such as pH, will open the door for construction of highly regulated systems in nanotechnology- and biology-driven applications. Here we report the green light induced [2+2] cycloaddition of a halochromic system based on a styrylquinoxaline moiety, which allows for its photo-reactivity to be switched on and off by adjusting the pH of the system. Critically, the [2+2] photocycloaddition can be activated by green light (λ up to 550 nm), which is the longest wavelength employed to date in catalyst-free photocycloadditions in solution. Importantly, the pH-dependence of the photo-reactivity was mapped by constant photon action plots. The action plots further indicate that the choice of solvent strongly impacts the system's photo-reactivity. Indeed, higher conversion and longer activation wavelengths were observed in water compared to acetonitrile under identical reaction conditions. The wider applicability of the system was demonstrated in the crosslinking of an 8-arm PEG to form hydrogels (ca. 1 cm in thickness) with a range of mechanical properties and pH responsiveness, highlighting the potential of the system in materials science.


Assuntos
Reação de Cicloadição/métodos , Hidrogéis/química , Luz , Processos Fotoquímicos , Animais , Catálise , Sobrevivência Celular , Fibroblastos , Concentração de Íons de Hidrogênio , Camundongos , Fótons , Polímeros/química , Reologia
10.
PLoS One ; 15(8): e0237583, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32804936

RESUMO

Identification and quantification of plant flavonoids are critical to pharmacokinetic study and pharmaceutical quality control due to their distinct pharmacological functions. Here we report on a novel plant flavonoid electrochemical sensor for sensitive and selective detection of dihydromyricetin (DMY) based on double- layered membranes consisting of gold nanoparticles (Au) anchored on reduced graphene oxide (rGO) and molecularly imprinted polymers (MIPs) modified glassy carbon electrode (GCE). Both rGO-Au and MIPs membranes were directly formed on GCE via in-situ electrochemical reduction and polymerization processes step by step. The compositions, morphologies, and electrochemical properties of membranes were investigated with X-ray powder diffractometry (XRD), Fourier transform infrared spectrum (FTIR), Field emission scanning electron microscopy (FESEM) combined with various electrochemical methods. The fabricated electrochemical sensor labeled as GCE│rGO-Au/MIPs exhibited excellent performance in determining of DMY under optimal experimental conditions. A wide linear detection range (LDR) ranges from 2.0×10-8 to 1.0×10-4 M together with a low limit of detection (LOD) of 1.2×10-8 M (S/N = 3) were achieved. Moreover, the electrochemical sensor was employed to determine DMY in real samples with satisfactory results.


Assuntos
Carbono/química , Técnicas Eletroquímicas/instrumentação , Flavonoides/análise , Flavonóis/análise , Grafite/química , Técnicas Biossensoriais/métodos , Eletrodos , Ouro , Limite de Detecção , Nanopartículas Metálicas , Impressão Molecular , Extratos Vegetais/análise , Polímeros/síntese química , Polímeros/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
11.
Int J Nanomedicine ; 15: 4933-4941, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32764926

RESUMO

Purpose: The aim of this study was to develop an avidin-modified macromolecular lipid magnetic sphere and its application in differential diagnosis of liver disease and liver cancer. Materials and Methods: Lectin-modified macromolecular lipid magnetic spheres were prepared by thin-film hydration method using lentil lectin derivatives (LCA-HQ) and cholesterol as raw materials. Alpha-fetoprotein variants (AFP-L3) in serum from healthy people, liver disease and liver cancer patients were isolated using the prepared lectin-modified macromolecular lipid magnetic spheres, and alpha-fetoprotein (AFP) and AFP-L3 were detected by fully automatic time-resolved fluorescence immunoassay. Results: The lectin polymer lipid magnetic sphere prepared in this study was superparamagnetic and encapsulated by a lectin derivative. There was no significant difference in the recovery rate of AFP-L3 between avidin magnetic ball-automatic time-resolved fluorescence immunoassay and manual micro-affinity column method (p>0.05). We found that AFP-L3 can be used as a differential indicator between liver cancer and liver disease. The positive rate of AFP and AFP-L3 in liver cancer patients was higher than that in healthy people and liver disease patients (p<0.001). The AUC (95% CI) of AFP and AFP-L3 were 0.743 ± 0.031 and 0.850 ± 0.024, respectively. AFP-L3 AUC value is greater than AFP; therefore, AFP-L3 distinguishes liver cancer more accurately, and the difference is statistically different, p<0.05. Conclusion: We proposed a novel method for integration of the lectin polymer lipid magnetic spheres and time-resolved fluorescence immunoassay that enables simple, accurate and rapid determination of AFP-L3 in clinical samples. To be noted, fully automatic time-resolved fluorescence immunoassay compared with the commonly used techniques in clinical practice, the measurement procedure is simple and is expected to be used for the detection and accurate diagnosis of liver cancer.


Assuntos
Fluorescência , Lipossomos/química , Neoplasias Hepáticas/diagnóstico , Mutação , Polímeros/química , alfa-Fetoproteínas/genética , alfa-Fetoproteínas/metabolismo , Adulto , Área Sob a Curva , Automação , Biomarcadores Tumorais/sangue , Feminino , Humanos , Imunoensaio/métodos , Neoplasias Hepáticas/sangue , Imãs/química , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
12.
Ecotoxicol Environ Saf ; 202: 110924, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800211

RESUMO

Fabrication of poly-(N-isopropylmethacrylamide-co-methacrylic acid) [p(NMA)] microgels to be utilized as microreactors to synthesize stable Ag nanoparticles for catalytic reductive degradation of dyes has been addressed in this work. Both p(NMA) microgel and Ag-p(NMA) hybrid microgel systems have been analyzed by Fourier transform infra-red and Dynamic light scattering, Ultraviolet-Visible spectroscopy, X-ray diffraction and Transmission electron microscopy. Catalytic activity of Ag-p(NMA) towards reductive degradation of Congo Red (CR), Methyl Orange (MO) and Alizarin Yellow (AY) was investigated under different operating conditions. Spectrophotometry was employed to check the progress of reaction while the rate constant (kapp) value of degradation reaction was determined under various conditions to optimize reaction parameters for rapid and economical degradation of these dyes. An increase in kapp value was observed by increasing feed content of dye up to a certain value that decreases again by further increment in dye concentration which reflects that catalysis follows Langmuir-Hinshelwood mechanism. A gradual increase in the kapp value was also observed with increasing quantity of hybrid microgel used as a catalyst. By comparing kapp values of degradation of aforementioned dyes, it was found that Ag-p(NMA) hybrid microgel gives better activity for MO dye degradation in comparison to catalytic degradation of CR and AY.


Assuntos
Compostos Azo/química , Nanopartículas Metálicas/química , Prata/química , Catálise , Corantes/química , Vermelho Congo/química , Hidrogéis/química , Microscopia Eletrônica de Transmissão , Polímeros/química , Espectrofotometria , Difração de Raios X
13.
J Chromatogr A ; 1626: 461369, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797848

RESUMO

Pumped sorbent tube sampling is a well established method for the sampling of volatile organic compounds (VOCs) and semi volatile organic compounds (SVOCs) in ambient, indoor and workplace atmospheres1. Safe sampling volumes and breakthrough volumes have been published for commonly found VOCs on widely used sorbents such as Tenax, however for newer sorbents and less commonly found VOCs there is less robust data. The Safe Sampling Volumes (SSVs) were determined from 15 tests of Retention Volume on 12 VOCs across the 3 sorbents. VOCs tested were: Aldehydes (C5, C6, C8, C9), Ketones (C4, C6), Alcohols (C3, C4), Furan, Limonene, Isoprene and Ethyl Acetate. 12 VOC / sorbent combinations gave SSVs large enough for practical sampling of indoor atmospheres, while SSVs for Furan on Carbopack-X, Isovaleraldehyde on Tenax TA and Methyl Ethyl Ketone on Tenax TA gave SSVs that were too small to be of practical use. This work identifies suitable sorbents and sampling volumes for the complete range of species tested.


Assuntos
Cromatografia Gasosa/métodos , Polímeros/química , Compostos Orgânicos Voláteis/análise , Adsorção , Poluição do Ar em Ambientes Fechados/análise , Aldeídos/química , Monitoramento Ambiental , Furanos/química , Compostos Orgânicos Voláteis/química
14.
J Chromatogr A ; 1626: 461389, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797860

RESUMO

The reliable measurement of very volatile organic compounds (VVOC) in indoor air by use of thermal desorption gas chromatography (TD-GC) in order to include them into evaluation schemes for building products even nowadays is a great challenge. For capturing these small molecules with carbon numbers ranging from C1C6, strong adsorbents are needed. In the present study, recovery rates of nine suitable adsorbents of the groups of porous polymers, graphitised carbon blacks (GCB) and carbon molecular sieves (CMS) are tested against a complex test gas standard containing 29 VVOC. By consideration of the recovery and the relative humidity (50% RH), combinations of the GCB Carbograph 5TD, the two CMS Carboxen 1003 and Carbosieve SII as well as the porous polymer Tenax® GR were identified to be potentially suitable for sampling the majority of the VVOC out of the gas mix. The results reveal a better performance of the adsorbents in combination than being used alone, particularly under humid sampling conditions. The recovery rates of the chosen compounds on each adsorbent should be in the range of 80-120%.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Compostos Orgânicos Voláteis/análise , Adsorção , Carbono/química , Gases/química , Umidade , Polímeros/química , Temperatura
15.
J Chromatogr A ; 1627: 461415, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823113

RESUMO

A molecularly imprinted polymeric monolith was synthesized in an aqueous environment in 15 min via UV-irradiation. The imprinted monolith was composed of hydroxyethyl methacrylate as monomer, dimethyl amino ethyl methacrylate as functional monomer, methylene bisacrylamide and piperazine diacrylamide as crosslinkers and human serum albumin as template molecule. The synthesis took place in a PDMS-based device (2.5 cm long) yielding a micro-solid phase extraction column (3 × 5 mm) with two built-in fingertight connectors for an infusion pump and fraction collector. The imprinted monolith displayed the characteristic features of a porous polymeric monolith, had dimethyl amino ethyl methacrylate and human serum albumin as functional groups within the monolith and showed high permeability (0.51 × 10-13 m2). 85% of the imprinted cavities were readily available for rebinding of human serum albumin with an imprinting factor of 1.3. In comparison to a non-imprinted monolith, molecular imprinting increased human serum albumin adsorption by > 30%. Imprinted monolith displayed selectivity for human serum albumin over other competing proteins (human transferrin, ovalbumin and carbonic anhydrase) with similar or different isoelectric points and size. Human serum albumin was adsorbed (in dynamic mode) with > 98% selectivity from diluted human plasma using the imprinted monolith device. Device to device reproducibility and reusability of the device for 5 cycles showcase the imprinted monolith micro-device efficiency.


Assuntos
Impressão Molecular , Proteínas/isolamento & purificação , Microextração em Fase Sólida/instrumentação , Adsorção , Etilaminas/química , Humanos , Metacrilatos/química , Permeabilidade , Polímeros/química , Porosidade , Reprodutibilidade dos Testes , Albumina Sérica Humana/isolamento & purificação , Espectroscopia de Infravermelho com Transformada de Fourier
16.
J Chromatogr A ; 1627: 461423, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823118

RESUMO

A novel stationary phase co-modified with N-isopropyl acrylamide (NIPAM) and 3-aminophenylboronic acid copolymer on the silica was synthesized through atom transfer radical polymerization (ATRP) reaction for performing mixed-mode and boronate affinity chromatography. The prepared functionalized silica was characterized using Fourier transform infrared spectrometry (FT-IR), elemental analysis (EA) and thermogravimetric analysis (TGA), scanning electron micrographs (SEM) and Brunauer-Emmett-Teller (BET) measurements. The prepared column named Sil-PBA-NIPAM showed great separation performance for hydrophobic, hydrophilic, positional isomer, acidic and alkaline compounds. Besides, the mixture of cis-diol and non-cis-diol compounds was used to prove that the developed column also has potential to capture and enrich cis-diol compounds. The prepared column possesses merits of time-saving, high selectivity to cis-diol compounds and molecular-planarity selectivity compared with two commercial single-mode columns. The theoretical plates of material can reach to 57472 and the column has good hydrolysis stability and batch-to-batch reproducibility. In summary, the prepared column possesses good hydrophilicity, hydrophobicity, molecular-planarity selectivity and boronate affinity abilities for the analysis of various compounds.


Assuntos
Acrilamidas/química , Ácidos Borônicos/química , Cromatografia/métodos , Polímeros/química , Ácido Benzoico/análise , Cromatografia de Fase Reversa , Hidrólise , Interações Hidrofóbicas e Hidrofílicas , Fenóis/análise , Polimerização , Reprodutibilidade dos Testes , Dióxido de Silício/química , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria
17.
Int J Nanomedicine ; 15: 5361-5376, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32801694

RESUMO

Background and Aim: Polymeric nanoparticles (NPs) have received much attention as promising carrier systems in lung cancer and brain metastases. Methods: Here, for the first time, we investigated the feasibility of using inhaled cholesterol-PEG co-modified poly (n-butyl) cyanoacrylate NPs (CLS-PEG NPs) of docetaxel (DTX) for sustained pulmonary drug delivery in cancer metastasis. Results: Spray-dried or freeze-dried NPs yielded sustained drug release in vitro. In vitro inhalation evaluation data indicated that the inhalation formulation had better inhalability. Compared with intravenous (IV) administration, pharmacokinetic data suggested that the inhalation formulation prolonged plasma concentration of DTX for greater than 24 h and is more quickly and completely absorbed into the rat lung after intratracheal (IT) administration. Furthermore, freeze-dried powders were found to increase the t1/2 and area under curve (AUC) by 2.3 and 6.5 fold compared to the free drug after IT administration, and spray-dried powders were found to increase the t1/2 and AUC by 3.4 and 8.8 fold, respectively. After pulmonary administration of the inhalation formulation, DTX appeared to prolong the pulmonary absorption time. In addition, the inhalation formulation was distributed to the brain in a sustained release manner. Conclusion: These experimental results demonstrated that freeze- and spray-dried powders have the potential for pulmonary sustained release, and they also have the potential to be used as a novel treatment for the delivery of drugs that pass through the air-blood barrier and enter the brain and are efficient carriers for the treatment of brain metastasis.


Assuntos
Antineoplásicos/administração & dosagem , Docetaxel/administração & dosagem , Neoplasias Pulmonares/tratamento farmacológico , Nanopartículas/administração & dosagem , Células A549 , Administração por Inalação , Animais , Encéfalo/efeitos dos fármacos , Colesterol/química , Preparações de Ação Retardada , Docetaxel/farmacocinética , Portadores de Fármacos/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Embucrilato/química , Feminino , Liofilização , Humanos , Pulmão/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Nanopartículas/química , Tamanho da Partícula , Polímeros/química , Pós/química , Ratos Wistar , Distribuição Tecidual
18.
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
19.
J Chromatogr A ; 1626: 461351, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797831

RESUMO

Traditional polymer-separation methods, such as size-exclusion chromatography and (gradient) liquid adsorption chromatography, cannot provide separations exclusively based on the number of deprotonated carboxylic-acid groups along the backbone chain of polymers. A novel separation method, based on non-aqueous ion-exchange chromatography (NAIEX), was developed, which allows such a separation of acid-functional polymers that are soluble in organic solvents. The polar, aprotic N-methyl-2-pyrrolidone was found to be a suitable solvent. It features a high relative permittivity (favouring dissociation of ion pairs into free ions) and it is a good solvent for polymers and organic salts, such as triethyl-ammonium formate. A negative charge is established on these polymers by deprotonation of the carboxylic-acid groups in the presence of an organic superbase (tetramethyl guanidine). Traditional potent organic bases, such as triethylamine, do not possess the base strength to compensate for the increase in pKa of polymeric carboxylic acid groups in non-aqueous conditions. Triethyl-ammonium formate is proposed as an alternative to traditional salts used for elution in aqueous ion-exchange chromatography. Separation was performed on an industry-standard strong-anion-exchange column and (near-)universal detection of the polymers was performed by high-temperature evaporative-light-scattering detection. The NAIEX method yielded a separation based on the acid-functionality distribution of the polymer. NAIEX was compared with traditional normal- and reversed-phase liquid-chromatography approaches for the separation of acid-functional copolymers.


Assuntos
Cromatografia por Troca Iônica/métodos , Cromatografia Líquida de Alta Pressão , Cromatografia de Fase Reversa , Polímeros/química , Espectroscopia de Prótons por Ressonância Magnética , Sais/química , Solventes/química
20.
J Chromatogr A ; 1626: 461360, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797839

RESUMO

Conjugated microporous polymers (CMPs) with uniform morphology have shown fascinating application in the separation science. In this study, metal-free Knoevenagel condensation was adopted to prepare spherical sp2 carbon-conjugated microporous polymers, which used tetrakis(4-formylphenyl)methane and 1,4-phenylenediacetonitrile as monomers. Due to the remarkable extraction capability for carbamate pesticides (CPs), the as-synthesized CMPs were fabricated as the coating for solid-phase microextraction (SPME). After optimized SPME parameters (adsorption time, salt concentration, sample pH, adsorption temperature, desorption time, desorption solvent and desorption volume), ten CPs in water samples were quantified by ultrahigh performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Linearity in the range 0.005-100 ng mL-1 with low detection limits of 0.00060-0.017 ng mL-1 was obtained. The intra-day and inter-day precisions expressed as relative standard deviations were 1.5-8.1% and 1.1-8.0%, respectively. Fiber-to-fiber reproducibility was below 7.3%. The CMPs-SPME-UPLC-MS/MS method was applied to detect trace CPs in real water samples with relative recoveries from 91.8% to 108%.


Assuntos
Carbamatos/análise , Microextração em Fase Sólida/métodos , Poluentes Químicos da Água/análise , Adsorção , Carbamatos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Praguicidas/análise , Praguicidas/isolamento & purificação , Polímeros/química , Porosidade , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem , Poluentes Químicos da Água/isolamento & purificação
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