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1.
Bull Environ Contam Toxicol ; 105(5): 806-812, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33057741

RESUMO

A molecularly imprinted polymer for the selective determination of Di(2-ethylhexyl) phthalate (DEHP) in water was synthesized and evaluated. This was accomplished by the use of sodium methacrylate as the monomer, toluene as a porogen, ethylene glycol dimethacrylate as a crosslinker, azobisisobutyronitrile as initiator and DEHP as a template molecule to generate the selectivity of the polymer for the compound, as well as synthesizing non-imprinted polymers. Three different polymerization approaches were used, emulsion, bulk and co-precipitation, the polymers obtained by emulsion presented a high retention rate reaching 99%. The method was able to pre-concentrate DEHP in water samples up to 250 times. To evaluate the applicability of the method, concentrations in fortified and bottled water were assessed using our polymer and determining DEHP concentrations by gas chromatography with mass spectrometry. Reported concentrations in bottled water were 12.1 µg/L, well above reference values established by the U.S. Environmental Protection Agency.


Assuntos
Dietilexilftalato/análise , Impressão Molecular/métodos , Polímeros , Poluentes Químicos da Água/análise , Água Potável/química , Cromatografia Gasosa-Espectrometria de Massas , Metacrilatos/química , Nitrilos/química , Polímeros/síntese química , Polímeros/química , Extração em Fase Sólida/métodos , Tolueno/química
2.
Yakugaku Zasshi ; 140(10): 1243-1249, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32999203

RESUMO

Here the author describes the tumor-selective delivery of a fluorescence photosensitizing agent and an antitumor agent, based on the polymer effect of an N-(2-hydroxypropyl)methacrylamide (HPMA) based copolymer, by utilizing the enhanced permeability and retention (EPR) effect seen in solid tumors. Firstly, the tumor distribution of the photosensitizer, zinc-protoporphyrin IX (ZnPP), was significantly increased by conjugation with the HPMA polymer (P-ZnPP). The P-ZnPP suppressed tumor growth by local generation of cytotoxic singlet oxygen, and the tumor tissue was visualized by fluorescence upon light irradiation. Subsequently, a two-step mechanism for tumor selectivity was observed for the cytotoxic anthracycline, pirarubicin (THP), which conjugated the HPMA-based copolymer via a hydrazone bond (P-THP). The EPR-dependent accumulation of P-THP and the tumor-selective release of THP in the tumor tissues led to highly tumor-selective toxicity. Rapid cell uptake of THP compared to other anthracyclines, and deeper P-THP penetration of the tumor cell spheroid were attributed to the superior antitumor activity of P-THP. The molecular weight of P-THP affected its antitumor activity; oligomeric P-THP derivatives with higher molecular weights, DP-THP and SP-THP, showed even higher antitumor activity. P-THP was effective for both implanted tumor and autochthonous tumor models. These results indicate that nano-sized anticancer drugs based on polymer effect are promising clinical therapeutics.


Assuntos
Antineoplásicos , Sistemas de Liberação de Medicamentos , Desenvolvimento de Medicamentos/métodos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Fármacos Fotossensibilizantes , Polímeros , Protoporfirinas , Animais , Antraciclinas/química , Antraciclinas/metabolismo , Antineoplásicos/química , Antineoplásicos/metabolismo , Doxorrubicina/análogos & derivados , Doxorrubicina/química , Doxorrubicina/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Metacrilatos/química , Terapia de Alvo Molecular , Peso Molecular , Neoplasias/patologia , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/metabolismo , Protoporfirinas/química , Protoporfirinas/metabolismo
3.
J Chromatogr A ; 1629: 461506, 2020 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-32866822

RESUMO

The development of a new, lower cost method for trace explosives recovery from complex samples is presented using miniaturised, click-together and leak-free 3D-printed solid phase extraction (SPE) blocks. For the first time, a large selection of ten commercially available 3D printing materials were comprehensively evaluated for practical, flexible and multiplexed SPE using stereolithography (SLA), PolyJet and fused deposition modelling (FDM) technologies. Miniaturised single-piece, connectable and leak-free block housings inspired by Lego® were 3D-printed in a methacrylate-based resin, which was found to be most stable under different aqueous/organic solvent and pH conditions, using a cost-effective benchtop SLA printer. Using a tapered SPE bed format, frit-free packing of multiple different commercially available sorbent particles was also possible. Coupled SPE blocks were then shown to offer efficient analyte enrichment and a potentially new approach to improve the stability of recovered analytes in the field when stored on the sorbent, rather than in wet swabs. Performance was measured using liquid chromatography-high resolution mass spectrometry and was better, or similar, to commercially available coupled SPE cartridges, with respect to recovery, precision, matrix effects, linearity and range, for a selection of 13 peroxides, nitramines, nitrate esters and nitroaromatics. Mean % recoveries from dried blood, oil residue and soil matrices were 79 ± 24%, 71 ± 16% and 76 ± 24%, respectively. Excellent detection limits between 60 fg for 3,5-dinitroaniline to 154 pg for nitroglycerin were also achieved across all matrices. To our knowledge, this represents the first application of 3D printing to SPE of so many organic compounds in complex samples. Its introduction into this forensic method offered a low-cost, 'on-demand' solution for selective extraction of explosives, enhanced flexibility for multiplexing/design alteration and potential application at-scene.


Assuntos
Substâncias Explosivas/análise , Extração em Fase Sólida/métodos , Cromatografia Líquida de Alta Pressão , Substâncias Explosivas/isolamento & purificação , Concentração de Íons de Hidrogênio , Limite de Detecção , Espectrometria de Massas , Metacrilatos/química , Nitroglicerina/análise , Nitroglicerina/isolamento & purificação , Peróxidos/análise , Peróxidos/isolamento & purificação , Impressão Tridimensional , Solventes/química
4.
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
5.
Int J Nanomedicine ; 15: 5377-5387, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32848384

RESUMO

Background: Periodontal pathogenic bacteria promote the destruction of periodontal tissues and cause loosening and loss of teeth in adults. However, complete removal of periodontal pathogenic bacteria, at both the bottom of the periodontal pocket and the root bifurcation area, remains challenging. In this work, we explored a synergistic antibiotic and photothermal treatment, which is considered an alternative strategy for highly efficient periodontal antibacterial therapy. Methods: Mesoporous silica (MSNs) on the surface of Au nanobipyramids (Au NBPs) were designed to achieve the sustained release of the drug and photothermal antibacterials. The mesoporous silica-coated Au NBPs (Au NBPs@SiO2) were mixed with gelatin methacrylate (GelMA-Au NBPs@SiO2). Au NBPs@SiO2 and GelMA-Au NBPs@SiO2 hybrid hydrogels were characterized, and the drug content and photothermal properties in terms of the release profile, bacterial inhibition, and cell growth were investigated. Results: The GelMA-Au NBPs@SiO2 hybrid hydrogels showed controllable minocycline delivery, and the drug release rates increased under 808 nm near-infrared (NIR) light irradiation. The hydrogels also exhibited excellent antibacterial properties, and the antibacterial efficacy of the antibiotic and photothermal treatment was as high as 90% and 66.7% against Porphyromonas gingivalis (P. gingivalis), respectively. Moreover, regardless of NIR irradiation, cell viability was over 80% and the concentration of Au NBPs@SiO2 in the hybrid hydrogels was as high as 100 µg/mL. Conclusion: We designed a new near-infrared light (NIR)-activated hybrid hydrogel that offers both sustained release of antibacterial drugs and photothermal treatment. Such sustained release pattern yields the potential to rapidly eliminate periodontal pathogens in the periodontal pocket, and the photothermal treatment maintains low bacterial retention after the drug treatment.


Assuntos
Antibacterianos/farmacologia , Hidrogéis/química , Hidrogéis/farmacologia , Porphyromonas gingivalis/efeitos dos fármacos , Animais , Antibacterianos/química , Antibacterianos/farmacocinética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Preparações de Ação Retardada/farmacologia , Liberação Controlada de Fármacos , Ouro/química , Hidrogéis/farmacocinética , Hidrogéis/efeitos da radiação , Lasers , Metacrilatos/química , Camundongos , Minociclina/química , Minociclina/farmacocinética , Minociclina/farmacologia , Nanoestruturas/química , Doenças Periodontais/tratamento farmacológico , Doenças Periodontais/microbiologia , Fototerapia/métodos , Dióxido de Silício/química
6.
J Chromatogr A ; 1625: 461238, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709314

RESUMO

In the present study, a novel strategy based on unidirectional freezing and atom transfer radical polymerization combined with activator regenerated by electron transfer (ARGET-ATRP) was applied to synthesizing orderly macroporous monolithic column with restricted-access (RA) property in a 1000µL pipette tip. The RA column was composed of hydrophobic inner column (poly(styrene-co-ethylene glycol dimethacrylate) and hydrophilic outer layer (poly-hydroxyethyl methacrylate chain) which was grafted on the hydrophobic surface by means of the second ARGET-ATRP reaction. The as-prepared RA monolithic tip was connected to a 2mL syringe for directly extracting magnolol and honokiol from rat plasma just by manually pushing operation. The surface morphology and chemical composition of the column were characterized by scanning electronic microscope, infrared spectroscopy and X-ray photoelectron spectroscopy respectively. The determined results of evaluation experiments based on the optimized solid phase extraction conditions showed that the RA column possessed good protein exclusion power, extraction recovery and reusability. The constructed RA-SPE-HPLC/UV method for simultaneously analyzing magnolol and honokiol in rat plasma was validated with quality control (QC) samples at four concentration levels. Good precision (RSDs, 3.39~11.16%) and acceptable accuracy (relative recoveries, 89.52%~108.42%) were obtained for intra- and inter-day assays. The determined results of real rat plasma as well as the standard-addition samples demonstrated the developed method with good accuracy and precision. It can be extrapolated from the experimental results that this simple and cost-efficient RA-SPE method is also suitable for directly extracting other hydrophobic constituents in biological body fluid for therapeutic drug monitoring or pharmacokinetic study.


Assuntos
Compostos de Bifenilo/sangue , Cromatografia Líquida de Alta Pressão/métodos , Lignanas/sangue , Metacrilatos/química , Polietilenoglicóis/química , Animais , Compostos de Bifenilo/isolamento & purificação , Compostos de Bifenilo/normas , Cromatografia Líquida de Alta Pressão/normas , Congelamento , Interações Hidrofóbicas e Hidrofílicas , Lignanas/isolamento & purificação , Lignanas/normas , Controle de Qualidade , Ratos , Reprodutibilidade dos Testes , Extração em Fase Sólida
7.
Int J Nanomedicine ; 15: 4591-4606, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32612358

RESUMO

Objective: Artemisinin (ART) is a natural anti-malarial sesquiterpene lactone which has the ability to treat and activate the CLRN1 pathway to play a pivotal role in hearing loss and hair cell function. To investigate the therapeutic effect of ART in hearing loss induced by gentamicin (GM), an ART-loaded poly(ethylene glycol)-b-poly(ε-caprolactone) mPEG-PCL nanoparticle-based photosensitive hydrogel was developed and tested in this study. Materials and Methods: Artemisinin-loaded mPEG-PCL nanoparticles (mPEG-PCL-ART-NPs) were prepared by a double emulsion method and the formulation was optimized by an orthogonal experimental design. The particle size, zeta potential, morphology and in vitro dissolution of the mPEG-PCL-ART-NPs were well characterized. Biocompatibility of the mPEG-PCL-ART-NPs were tested on HeLa cells with an MTT assay. The photo-crosslinkable biodegradable gelatin methacrylate (GelMA) hydrogel was prepared and its physicochemical properties (such as substitution, photocrosslinking efficiency, cell viability morphology, mechanical and swelling properties) were evaluated. Finally, mPEG-PCL-ART-FITC-NPs, loaded mPEG-PCL-ART-NPs, and loaded mPEG-PCL-ART-NPs-GelMA hydrogels were fabricated and a GM toxicity-induced guinea pig ear damage model was established to determine the effectiveness of the materials on returning auditory function and cochlea pathomorphology. Results: The zeta potential of the mPEG-PCL-ART-NPs was about -38.64 ± 0.21 mV and the average size was 167.51 ± 1.87 nm with an encapsulation efficacy of 81.7 ± 1.46%. In vitro release studies showed that the mPEG-PCL-ART-NPs possessed a sustained-release effect and the MTT experiments showed good biocompatibility properties of the drug-loaded nanoparticles. The results indicated that the 5% GelMA with MA-4% hydrogel had a better crosslinking density and 3D structure for drug loading and drug delivery than controls. Skin penetration results showed that the mPEG-PCL-ART-NPs increased adhesive capacity and avoided fast diffusion in the skin. Most importantly, auditory brainstem response results indicated that the mPEG-PCL-ART-NPs-GelMA hydrogel alleviated hearing loss induced by GM. Conclusion: These results suggested that the presently fabricated mPEG-PCL-ART-NPs-GelMA hydrogels are promising formulations for the treatment of hearing loss induced by GM and lay the foundation for further clinical research of inner ear induction therapy.


Assuntos
Artemisininas/administração & dosagem , Artemisininas/farmacologia , Gentamicinas/efeitos adversos , Perda Auditiva/tratamento farmacológico , Hidrogéis/administração & dosagem , Animais , Artemisininas/farmacocinética , Sistemas de Liberação de Medicamentos , Etilenoglicóis/química , Gelatina , Cobaias , Células HeLa , Perda Auditiva/induzido quimicamente , Humanos , Hidrogéis/química , Metacrilatos/química , Nanopartículas/química , Tamanho da Partícula , Poliésteres/química , Polietilenoglicóis/química
8.
J Chromatogr A ; 1624: 461155, 2020 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-32540056

RESUMO

The topic in the present paper is to prepare molecularly imprinted polymer (MIP) using the template molecule with low purity. For the first time, a surrounding of macromolecular crowding was established to promote the formation of the complex of the template with functional monomer efficiently thus highly pure template molecule was unnecessary. In this study, the MIP monolith was synthesized using low purity lactucopicrin as template in place of highly pure one, and polystyrene was used as macromolecular crowding agent. 4-Vinylpyridine and ethyleneglycol dimethacrylate were used as functional monomer and crosslinker, respectively. Polymerization parameters, including the ratio of functional monomer/template, various template concentrations, and PS concentration on the affinity of the resulting MIP were systematically investigated. For the lactucopicrin MIP made with the purity of lactucopicrin of 92%, the imprinting factor can be up to 2.2. The resulting MIP was filled in solid phase extraction (SPE) cartridge to purify lactucopicrin from the crude extract of Cichorium glandulosum Boiss. et Huet. After two cycles of MIP SPE for the crude extract, the highest recovery and purity of lactucopicrin was 64.8% and 97.8%, respectively. The results indicated that the use of macromolecular crowding agent is an effective method for improving the performance of the MIP prepared with the template of low purity, particularly valuable to the cases in which the highly pure target molecule is hard to be obtained.


Assuntos
Impressão Molecular , Polímeros/química , Asteraceae/química , Reagentes para Ligações Cruzadas/química , Lactonas/química , Lactonas/isolamento & purificação , Metacrilatos/química , Polimerização , Poliestirenos/química , Piridinas/química , Sesquiterpenos/química , Sesquiterpenos/isolamento & purificação , Extração em Fase Sólida
9.
J Chromatogr A ; 1623: 461154, 2020 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-32505273

RESUMO

Chiral stationary phases (CSPs) have always been research hotspot in enantiomer separation. Currently, most of the CSPs are based on silica platform. In this research, monodisperse, porous glycidyl methacrylate-divinylbenzene copolymer particles (poly(GMA-DVB)) were designed and prepared. Then the GMA was further reacted with ethylenediamine to introduce amino groups onto the polymer, which provide anchoring sites for cellulose derivatives. Herein, Cellulose-tris (3,5-dimethylphenylcarbamate) (CDMPC) was successfully coated onto the polymer microspheres, achieving a stable and successful CSP. The porous structure and the surface moieties of the CSPs were studied in detail. The chromatographic separation was optimized. Hexaconazole,methyl DL-mandelate,benzoin and tebuconazole have been successfully separated on the CSP column, with column efficiency as high as 10,200 plates/m, which is comparable with some silica-based CSPs. The research has indicated that the poly(GMA-DVB) is a promising candidate for constructing CSPs for chiral separation.


Assuntos
Celulose/análogos & derivados , Microesferas , Fenilcarbamatos/química , Polímeros/química , Celulose/química , Cromatografia Líquida de Alta Pressão/métodos , Compostos de Epóxi/química , Metacrilatos/química , Porosidade , Dióxido de Silício/química , Estereoisomerismo , Triazóis/química , Compostos de Vinila/química
10.
J Chromatogr A ; 1623: 461175, 2020 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-32505279

RESUMO

An ionic liquid hybrid zwitterionic polymer capillary microextraction (CME) column was prepared for the biomimetic enrichment of glycopeptides by one-step copolymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) and 1-butyl-3-vinylimidazolium bromide, in the presence of crosslinker trimethylolpropane trimethacrylate (TMA). The resultant monolith was characterized by scanning electron microscopy (SEM), fourier transform infrared (FT-IR) spectroscopy and pore size distribution measurement. Due to the incorporation of zwitterionic MPC owning a unique biomimic structure (i.e. hydrophilic cation/anion and hydrophobic long-alkyl chain), the monolithic column has large pore size and good biocompatibility, exhibiting high extraction efficiency, permeability and fast mass transfer to targets. Besides, the use of ionic liquids (ILs) as co-monomer in the polymerization endows the monolith with enhanced mechanical stability, uniformity and multiple interactions. The prepared column was successfully applied in CME coupled to capillary electrochromatography (CEC) for the efficient enrichment and separation of glycopeptide antibiotics in foodstuff. The method demonstrated a wide linear range (50.0-18000.0 µg L-1), low detection limits (5.0-10.0 µg L-1, S/N = 3) and satisfied recoveries (76.0-109.7%). This work shows the advantage of fine-tuning biomimetic monoliths in application-specific CME-CEC.


Assuntos
Antibacterianos/análise , Eletrocromatografia Capilar/métodos , Glicopeptídeos/análise , Líquidos Iônicos/química , Antibacterianos/isolamento & purificação , Materiais Biomiméticos , Fracionamento Químico , Análise de Alimentos/métodos , Glicopeptídeos/isolamento & purificação , Interações Hidrofóbicas e Hidrofílicas , Imidazóis/química , Metacrilatos/química , Microscopia Eletrônica de Varredura , Fosforilcolina/análogos & derivados , Fosforilcolina/química , Polimerização , Polímeros/química , Espectroscopia de Infravermelho com Transformada de Fourier , Compostos de Vinila/química
11.
Food Chem ; 331: 127311, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32569967

RESUMO

A magnetic hydrophilic molecularly imprinted material (MIM) with multiple stimuli-responses was prepared for efficient recognition of bisphenol A (BPA). MIM consisted of a magnetic core, an inner silica dioxide shell and an outer hydrophilic polymer shell, responsive for rapid magnetic separation, protection of the magnetic core and pH-/thermo-sensitivity to BPA, respectively. Controlled adsorption and release of BPA by pH/temperature regulation were realized through the reversible components of poly[N-isopropylacrylamide-co-2-(dimethylamino)ethyl methacrylate (NIPAM-DMAEMA)] (PND). The resultant MIM possessed superior affinity, selectivity and kinetics to BPA in aqueous solution. MIM was successfully applied to detect BPA in beverages via dispersive solid-phase extraction (d-SPE) coupled with high performance liquid chromatography (HPLC), exhibiting satisfactory recoveries of 80.70-108.18% with relative standard deviations (RSD) below 6.08%. The limit of detection of BPA was obtained as low as 3.75 nmol/L. The versatile MIM could be a promising alternative for extraction/removal of BPA in complicated samples by multiple-stimuli regulations.


Assuntos
Compostos Benzidrílicos/química , Bebidas/análise , Imãs/química , Impressão Molecular , Fenóis/química , Polímeros/química , Polímeros/síntese química , Adsorção , Compostos Benzidrílicos/análise , Compostos Benzidrílicos/isolamento & purificação , Interações Hidrofóbicas e Hidrofílicas , Metacrilatos/química , Fenóis/análise , Fenóis/isolamento & purificação , Dióxido de Silício/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
12.
J Chromatogr A ; 1622: 461097, 2020 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-32381302

RESUMO

In this study, polymeric monoliths with gold nanoparticles (AuNP@monolith) were investigated as microcartridges for the analysis of protein biomarkers by on-line solid-phase extraction capillary electrophoresis-mass spectrometry (SPE-CE-MS). "Plug-and-play" microcartridges (7 mm) were prepared from a glycidyl methacrylate (GMA)-based monolithic capillary column (5 cm x 250 µm i.d.), which was modified with ammonia and subsequently functionalized with gold nanoparticles (AuNPs). The performance of these novel microcartridges was evaluated with human transthyretin (TTR), which is a protein related to different types of familial amyloidotic polyneuropathies (FAP). Protein retention depended on the isoelectric point of the protein (TTR pI~5.4) and elution was achieved with a basic phosphate solution. Under the optimized conditions, limits of detection (LODs) for TTR by AuNP@monolith-SPE-CE-MS were 50 times lower than by CE-MS (5 vs 250 mg•L-1, with an ion trap (IT) mass spectrometer). The sensitivity enhancement was similar compared to SPE-CE-MS using immunoaffinity (IA) microcartridges with intact antibodies against TTR. Linearity, repeatability in migration times and peak areas, reusability, reproducibility and application to serum samples were also evaluated.


Assuntos
Biomarcadores , Eletroforese Capilar , Ouro , Espectrometria de Massas , Nanopartículas Metálicas , Pré-Albumina , Extração em Fase Sólida , Biomarcadores/análise , Compostos de Epóxi/química , Ouro/química , Humanos , Limite de Detecção , Nanopartículas Metálicas/química , Metacrilatos/química , Polímeros/química , Pré-Albumina/análise , Reprodutibilidade dos Testes
13.
J Vis Exp ; (159)2020 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-32421007

RESUMO

During the extrusion-based three-dimensional bioprinting process, liquid-like bioinks with low viscosity can protect cells from membrane damage induced by shear stress and improve the survival of the encapsulated cells. However, rapid gravity-driven cell sedimentation in the reservoir could lead to an inhomogeneous cell distribution in bioprinted structures and therefore hinder the application of liquid-like bioinks. Here, we developed a novel multilayered modified strategy for liquid-like bioinks (e.g., gelatin methacryloyl with low viscosity) to prevent the sedimentation of encapsulated cells. Multiple liquid interfaces were manipulated in the multilayered bioink to provide interfacial retention. Consequently, the cell sedimentation action going across adjacent layers in the multilayered system was retarded in the bioink reservoir. It was found that the interfacial retention was much higher than the sedimental pull of cells, demonstrating a critical role of the interfacial retention in preventing cell sedimentation and promoting a more homogeneous dispersion of cells in the multilayered bioink.


Assuntos
Materiais Biocompatíveis/química , Bioimpressão , Células/metabolismo , Hidrogéis/química , Tinta , Impressão Tridimensional , Animais , Sobrevivência Celular , Fibroínas/química , Gelatina/química , Metacrilatos/química , Camundongos , Células NIH 3T3 , Viscosidade
14.
Langmuir ; 36(16): 4396-4404, 2020 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-32255641

RESUMO

Tissue-engineered vascular graft (TEVG) is a promising alternative to meet the clinical demand of organ shortages. Herein, human hair keratin was extracted by the reduction method, followed by modification with zwitterionic 2-methacryloyloxyethyl phosphorylcholine (MPC) through thiol-Michael addition to improve blood clotting nature. Then, phosphobetainized keratin (PK) was coelectrospun with poly(ε-caprolactone) (PCL) to afford PCL/PK mats with a ratio of 7:3. The surface morphology, chemical structure, and wettability of these mats were characterized. The biocomposite mats selectively enhanced adhesion, migration, and growth of endothelial cells (ECs) while suppressed proliferation of smooth muscle cells (SMCs) in the presence of glutathione (GSH) and GSNO due to the catalytic generation of NO. In addition, these mats exhibited good blood anticoagulant activity by reducing platelet adhesion, prolonging blood clotting time, and inhibiting hemolysis. Taken together, these NO-generating PCL/PK mats have potential applications as a scaffold for vascular tissue engineering with rapid endothelialization and reduced SMC proliferation.


Assuntos
Materiais Biocompatíveis/química , Queratinas/química , Óxido Nítrico/farmacologia , Poliésteres/química , Tecidos Suporte/química , Catálise , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cabelo/química , Células Endoteliais da Veia Umbilical Humana , Humanos , Metacrilatos/química , Fosforilcolina/análogos & derivados , Fosforilcolina/química , Adesividade Plaquetária/efeitos dos fármacos , Engenharia Tecidual
15.
Talanta ; 214: 120860, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32278420

RESUMO

A glycidyl methacrylate-based monolith was modified with imidazolium-based ionic liquid (IL) to be used as stationary phase for solid-phase extraction (SPE). The host monolithic support was prepared by in-situ UV polymerization in spin column format. Two approaches were developed to incorporate the IL into the polymeric monolithic matrix: generation of IL onto the surface monolith, and copolymerization by addition of the IL to the polymerization mixture, which gave the best results. The resulting sorbent materials were morphologically characterized and used for the isolation of five ß-blockers from human urine samples. All SPE steps were accomplished by centrifugation, which reduces significantly costs and time in sample treatment. Under optimal conditions, ß-blockers were quantitatively retained in the modified monolith at pH 12, and desorbed with a water-methanol mixture, to be subsequently determined via HPLC with UV detection. The limits of detection ranged between 1.4 and 40 µg L-1, and the reproducibility among extraction units (expressed as relative standard deviation) was below 8.2%. The novel phase was successfully applied to the extraction of propranolol in urine samples with recoveries above 90%.


Assuntos
Antagonistas Adrenérgicos beta/isolamento & purificação , Compostos Alílicos/química , Compostos de Epóxi/química , Imidazóis/química , Metacrilatos/química , Polímeros/química , Extração em Fase Sólida , Antagonistas Adrenérgicos beta/química , Antagonistas Adrenérgicos beta/urina , Humanos , Tamanho da Partícula , Propriedades de Superfície
16.
J Appl Oral Sci ; 28: e20190499, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32348441

RESUMO

Enzymatic degradation of the hybrid layer can be accelerated by the activation of dentin metalloproteinases (MMP) during the bonding procedure. MMP inhibitors may be used to contain this process. Objective To evaluate the degree of conversion (DC%), dentin bond strength (µTBS) (immediate and after 1 year of storage in water), and nanoleakage of an experimental (EXP) and a commercial (SB) adhesive system, containing different concentrations of the MMP inhibitor GM1489: 0, 1 µM, 5 µM and 10 µM. Methodology DC% was evaluated by FT-IR spectroscopy. Dentin bond strength was evaluated by µTBS test. Half of beams were submitted to the µTBS test after 24 h and the other half, after storage for 1 year. From each tooth and storage time, 2 beams were reserved for nanoleakage testing. Data were analyzed using ANOVA and Tukey's test to compare means (α=0.05). Results All adhesive systems maintained the µTBS after 1 year of storage. Groups with higher concentrations of inhibitor (5 µM and 10 µM) showed higher µTBS values than groups without inhibitor or with 1 µM. The nanoleakage values of all groups showed no increase after 1 year of storage and values were similar for SB and EXP groups, in both storage periods. The inhibitor did not affect the DC% of the EXP groups, but the SB5 and SB10 groups showed higher DC% values than those of SB0 and SB1. Conclusions The incorporation of GM1489 in the adhesive systems had no detrimental effect on DC%. The concentrations of 5 µM GM1489 for SB and 5 µM or 10 µM for EXP provided higher µTBS than groups without GM1489, in the evaluation after 1 year of storage; whereas the concentration of inhibitor did not affect adhesive systems nanoleakage.


Assuntos
Cimentos Dentários/química , Dentina/química , Inibidores de Metaloproteinases de Matriz/química , Metacrilatos/química , Polietilenoglicóis/química , Ácidos Polimetacrílicos/química , Análise de Variância , Colagem Dentária/métodos , Corrosão Dentária/métodos , Infiltração Dentária , Dentina/efeitos dos fármacos , Humanos , Teste de Materiais , Valores de Referência , Reprodutibilidade dos Testes , Espectroscopia de Infravermelho com Transformada de Fourier , Estatísticas não Paramétricas , Propriedades de Superfície , Resistência à Tração , Fatores de Tempo
17.
Phys Chem Chem Phys ; 22(17): 9573-9586, 2020 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-32322851

RESUMO

Synthesizing and understanding phase transition behavior of novel block copolymers is very crucial for fabricating next generation of smart materials with foreseeable applications. In this regard, we synthesized three random (r) copolymers of poly(N-vinyl-caprolactam) (PVCL) and poly(2-dimethyl amino ethyl methacrylate) (PDMAEMA) with varying percentages of each block and characterized them using nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) patterns, time-resolved fluorescence spectroscopy, and atomic force microscopy (AFM). Synthesized copolymers i.e. PVCL30-PDMAEMA70, PVCL50-PDMAEMA50 and PVCL70-PDMAEMA30 have fluorescence properties, which were confirmed by time-resolved fluorescence spectra and emission spectra, and emission bands were observed at ∼310, ∼435 and ∼424 nm, respectively. The fluorescence lifetime for PVCL50-PDMAEMA50 is larger than those of the other two copolymers suggesting a slow decay of the excited state. The copolymers have spherical geometry as micelles, which were confirmed by TEM. We observed patterned arrangement of micelles and the arranged micelles appear to be pentagon in shape, creating space in between the arranged micelles; however, for PVCL50-PDMAEMA50, the arranged micelles do not form any particular shape. The thermal phase transition of PVCL-r-PDMAEMA in aqueous solution was studied by differential scanning calorimetry and thermal fluorescence spectroscopy. In order to design a biomimetic polymer for bio-specific applications and to understand novel concepts towards polymer-protein interactions, we studied the effect of insulin on lower critical solution temperature (LCST) of PVCL-r-PDMAEMA using multiple sophisticated techniques. The LCST is finely tuned by incorporation of two blocks with various block compositions and the value falls within the range of human body temperature, making PVCL50-PDMAEMA50 a highly compatible material for bio-medical and bio-material applications. Insulin forms a self-assembly with the monomers of PVCL-r-PDMAEMA, which leads to enhancing the micellar aggregates and the eventual decrease in the LCST of the diblock copolymer aqueous solution. The present study provides new insights into insulin-copolymer interactions and can be used for self-assembling nanocarriers and designing protein resistance surfaces.


Assuntos
Insulina/química , Micelas , Conformação Molecular , Polímeros/química , Etilaminas/química , Metacrilatos/química , Multimerização Proteica
18.
Biofouling ; 36(3): 245-255, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32326753

RESUMO

Dental plaque is a biofilm composed of a complex oral microbial community. The accumulation of plaque in the pit and fissures of dental elements often leads to the development of tooth decay (dental caries). Here, potent anti-biofilm materials were developed by incorporating zinc methacrylates or di-n-butyl-dimethacrylate-tin into the light-curable sealant and their physical, mechanical, and biological properties were evaluated. The data revealed that 5% di-n-butyl-dimethacrylate-tin (SnM 5%) incorporated sealant showed strong anti-biofilm efficacy against various single-species (Streptococcus mutans or Streptococcus oralis or Candida albicans) and S. mutans-C. albicans cross-kingdom dual-species biofilms without either impairing the mechanical properties of the sealant or causing cytotoxicities against mouse fibroblasts. The findings indicate that the incorporation of SnM 5% in the experimental pit and fissure self-adhesive sealant may have the potential to be part of current chemotherapeutic strategies to prevent the formation of cariogenic oral biofilms that cause dental caries.


Assuntos
Adesivos/farmacologia , Biofilmes/efeitos dos fármacos , Cárie Dentária/prevenção & controle , Selantes de Fossas e Fissuras/farmacologia , Zinco/química , Adesivos/química , Animais , Biofilmes/crescimento & desenvolvimento , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Cárie Dentária/microbiologia , Humanos , Metacrilatos/química , Camundongos , Microbiota/efeitos dos fármacos , Selantes de Fossas e Fissuras/química , Streptococcus mutans/efeitos dos fármacos , Streptococcus mutans/crescimento & desenvolvimento , Streptococcus oralis/efeitos dos fármacos , Streptococcus oralis/crescimento & desenvolvimento
19.
Molecules ; 25(6)2020 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-32204526

RESUMO

Swellable polymers that respond to pH (including a portion of the physiological pH range) have been prepared from N-isopropylacrylamide (NIPA) copolymerized with acrylic acid, methacrylic acid, ethacrylic acid or propacrylic acid by dispersion polymerization. When the swellable polymer particles are dispersed in a polyvinyl alcohol (PVA) hydrogel membrane, large changes occur in the turbidity of the membrane (which is measured using an absorbance spectrometer) as the pH of the buffer solution in contact with the hydrogel membrane is varied. The swelling of the NIPA copolymer is nonionic, as the ionic strength of the buffer solution in contact with the PVA membrane was increased from 0.1 to 1.0 M without a decrease in the swelling. For many of these NIPA copolymers, swelling was also reversible in both low- and high ionic strength pH-buffered media and at ambient and physiological temperatures. The composition of the formulation used to prepare these copolymers of NIPA can be correlated to the enthalpy and entropy of the pH-induced swelling.


Assuntos
Acrilamidas/química , Acrilatos/química , Polímeros/química , Entropia , Concentração de Íons de Hidrogênio , Metacrilatos/química , Álcool de Polivinil/química
20.
Talanta ; 212: 120778, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32113541

RESUMO

Tailor-made Escherichia coli (E. coli) receptors were created with microcontact imprinted technique and binding events of E. coli were carried out by a surface plasmon resonance (SPR) sensor in aqueous solution and in urine mimic in real time and label-free. N-methacryloyl-(l)-histidine methyl ester (MAH) was selected as a functional monomer to design tailor-made E. coli receptors on the polymeric film and during the formation of the polymeric film on a chip surface, Ag nanoparticles (AgNPs) were entrapped into the polymer mixture in order to lower the detection limit of biomimetic SPR based sensor. The polymeric film was characterized with atomic force microscopy (AFM), scanning electron microscopy (SEM), ellipsometer and contact angle measurements. Limit of detection (LOD) was found 0.57 CFU/mL and feasibility of the biomimetic sensor was investigated in urine mimic.


Assuntos
Técnicas de Tipagem Bacteriana/métodos , Escherichia coli/isolamento & purificação , Ácidos Polimetacrílicos/química , Ressonância de Plasmônio de Superfície/métodos , Infecções Urinárias/diagnóstico , Biomimética/métodos , Histidina/análogos & derivados , Histidina/química , Limite de Detecção , Nanopartículas Metálicas/química , Metacrilatos/química , Impressão Molecular , Prata/química , Urina/microbiologia
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