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1.
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
2.
J Chromatogr A ; 1628: 461424, 2020 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-32822969

RESUMO

Block copolymers that exhibit both an upper critical solution temperature and a lower critical solution temperature are difficult to characterize due to inherent solubility difference between the two blocks. For example, accurate determination of both the molar mass and molar mass distribution is challenging for polyzwitterion-block-N-isopropyl acrylamide (NIPAM) copolymers in aqueous solutions due to self-assembly. However, there are a few examples of using size exclusion chromatography (SEC) for characterization, in which hexafluoro isopropanol (HFIP) is used in all cases. Yet, researchers are hesitant to use this solvent due to how expensive and hazardous HFIP is. Therefore, alternatives to HFIP for SEC analysis would be desirable. Here, a systematic methodology featuring aqueous SEC is demonstrated using several solvent conditions to enable the elution of polyzwitterion-block-NIPAM copolymers on Agilent PolarGel† and Tosoh TSKgel† column sets. These SEC conditions include 0.2 M KI in water on the PolarGel columns and 0.2 M KI/ 30% DMF in water on the PolarGel and TSKgel columns. These aqueous systems can be utilized for the characterization of similar water-soluble block copolymers that are relevant for drug delivery and other biomedical applications.


Assuntos
Acrilamidas/química , Cromatografia em Gel/métodos , Polímeros/química , Acrilamidas/síntese química , Polimerização , Polímeros/síntese química , Sais/química , Solventes/química , Ácidos Sulfônicos/síntese química , Ácidos Sulfônicos/química , Temperatura , Água
3.
Food Chem ; 332: 127404, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32623127

RESUMO

Coumarins, derivatives of cinnamic acid, are found in wines aged in wooden barrels. The lab-made molecularly imprinted polymers (MIP), selective for simple coumarins, were used in three forms, as sorbents in solid phase extraction (SPE) cartridge or pipette tip and coated on to the surface of magnetite for magnetic extraction. MIP-7-hydroxycoumarin had greater selectivity and extraction efficiency (recoveries above 75%, RSDs less than 6%) compared with conventional SPE sorbents (C18 and styrene-divinylbenzene polymeric types). Batch extraction with MIP coated on to magnetic particles was relatively time-consuming compared with conventional and pipette tip SPE. The advantage of pipette tip SPE was reduced solvent volumes. LOQs for MISPE offline coupled with HPLC were less than 1.5 µg mL-1 and 12 ng mL-1 for UV and fluorescence detectors, respectively. 6-Methoxy-7-hydroxycoumarin and 4-methyl-7-hydroxycoumarin were detected in Slovak Tokaj wines using method with coumarin-specific sorbents.


Assuntos
Cumarínicos/isolamento & purificação , Extração em Fase Sólida/métodos , Adsorção , Cromatografia Líquida de Alta Pressão , Cumarínicos/química , Impressão Molecular , Polímeros/síntese química , Polímeros/química , Solventes/química , Estireno/química
4.
Food Chem ; 333: 127540, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32682226

RESUMO

A novel of magnetic dummy-template molecularly imprinted polymers (mag-MWCNTs-DMIPs) were prepared by surface molecular imprinting technique. The structure of polymers were characterized and the binding properties were assessed by adsorption experiments. The synthetic mag-MWCNTs-DMIPs exhibit satisfying adsorption capacity, excellent selectivity and fast adsorption rate toward phenoxy carboxylic acid (PCA) herbicides. Afterwards, a reliable analytical method for selective separation and determination of trace PCA herbicides in cereals was established by using magnetic solid-phase extraction (mag-MWCNTs-DMIPs as magnetic adsorbent) and UPLC-MS/MS detection. A series of requisite factors were optimized in detail to achieve expected extraction performance. Under the optimum MSPE parameters, the mean spiked recoveries for analytes in different cereals ranged from 86.7% to 95.2% with intra- and inter-day precision not greater than 8.5% and 10.6%, respectively. At last, the developed method was successfully utilized for determination the four PCA herbicides in actual cereals.


Assuntos
Ácidos Carboxílicos/análise , Ácidos Carboxílicos/isolamento & purificação , Grão Comestível/química , Herbicidas/química , Impressão Molecular , Nanotubos de Carbono/química , Extração em Fase Sólida/métodos , Adsorção , Ácidos Carboxílicos/química , Contaminação de Alimentos/análise , Imãs/química , Polímeros/síntese química , Polímeros/química , Fatores de Tempo
5.
J Chromatogr A ; 1625: 461298, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709341

RESUMO

This study has examined the batch binding behaviour of different thermo-responsive co-polymer grafted chromatographic materials under different temperature and protein loading conditions. The effect of molecular composition of poly(N-isopropylacrylamide) (PNIPAAm)-based co-polymers on the phase transition properties has been documented. Sixteen co-polymers of different compositions were synthesized by free radical polymerization methods. Most underwent relatively sharp phase transitions upon application of increasing temperature. However, the value of the lower critical solution temperature (LCST) varied due to differences in co-polymer compositions. In general, it was found that the LCST increased for co-polymers containing more hydrophilic moieties, but decreased for co-polymers with more hydrophobic moieties. Moreover, the LCST increased, together with increased width of the transition temperature, when highly branched monomeric moieties (i.e. N­tert­octyl groups) were present. When bulky side chains (octadecyl or triphenylmethyl groups) were located in the polymer structures the LCST transition was absent. Based on these findings, 6 thermo-responsive co-polymers of different compositions were individually immobilised onto cross-linked Sepharose 6 Fast Flow by a "grafting-from" method. Bovine holo-lactoferrin and bovine holo-transferrin at different concentrations in the range 1-100 mg/mL were then employed as target proteins to evaluate the adsorption behaviour under batch binding conditions with these different polymer grafted Sepharose 6 Fast Flow sorbents at two different temperatures. In general, all sorbents exhibited greater affinity and adsorption capacity for bovine holo-lactoferrin at 50 °C compared to 20 °C. In addition, the affinity and adsorption capacity of bovine holo-lactoferrin with positively charged copolymer grafted Sepharose 6 Fast Flow chromatographic sorbents at 20 °C and 50 °C were much lower than that found for negatively charged copolymer grafted Sepharose 6 Fast Flow sorbents, whilst the opposite trend was found with bovine holo-transferrin due to differences in the surface charge properties of these two proteins, indicative of different separation selectivity. Furthermore, the structure of the side chains present in the grafted copolymer structure was found to affect the adsorption performance of both proteins at 20 °C and 50 °C.


Assuntos
Polímeros/química , Proteínas/química , Reologia , Sefarose/química , Temperatura , Resinas Acrílicas/síntese química , Resinas Acrílicas/química , Adsorção , Animais , Bovinos , Interações Hidrofóbicas e Hidrofílicas , Lactoferrina/química , Polimerização , Polímeros/síntese química , Transferrina/química
6.
J Chromatogr A ; 1623: 461192, 2020 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-32505285

RESUMO

An imidazolium ionic-liquid-modified phenolic resin (ILPR) was synthesized using 3-aminophenol as a functional monomer, glyoxylic acid as a green cross-linker, and polyethylene glycol 6000 as a porogen. The obtained ILPR showed better extraction of benzoylurea plant hormones thidiazuron and forchlorfenuron than the unmodified phenolic resin because the imidazolium IL provides more interaction modes with the analytes. ILPR, as a tailored adsorbent for solid-phase extraction, was coupled with high-performance liquid chromatography (ILPR‒SPE‒HPLC) for the simultaneous determination of thidiazuron and forchlorfenuron in cucumbers. Good linearity of the ILPR‒SPE‒HPLC method was obtained, ranging from 0.0100 to 5.00 µg g-1 with a correlation coefficient (r) ≥ 0.9999. The recoveries of spiked samples ranged from 91.4% to 100.7% with a relative standard deviation of ≤ 6.0%.


Assuntos
Cucumis sativus/química , Formaldeído/química , Imidazóis/química , Líquidos Iônicos/química , Fenóis/química , Compostos de Fenilureia/isolamento & purificação , Polímeros/química , Piridinas/isolamento & purificação , Extração em Fase Sólida/métodos , Tiadiazóis/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Formaldeído/síntese química , Líquidos Iônicos/síntese química , Cinética , Fenóis/síntese química , Polímeros/síntese química , Reprodutibilidade dos Testes
7.
Food Chem ; 328: 127063, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-32485582

RESUMO

A magnetic fluorescence probe was fabricated by coating carbon quantum dots-doped molecularly imprinted polymers (MIPs) layers on the surface of Fe3O4 particles (MFMP) for detection of N-acyl homoserine lactones (AHLs) signaling molecules. N-Z-L-homoserine lactone molecular was used as the template to prepare AHLs MIP layers, employing MAA and HEMA as functional monomers. The developed MFMP owned superparamagnetism, fluorescence, fast response and class-selectivity. If AHLs (C4-HSL, C6-HSL, C8-HSL, C10-HSL, C12-HSL and C14-HSL) were captured by the MFMP, they quenched the fluorescence of the probe. Fluorescence dropped linearly in the concentration ranges of 3.65 × 10-3 µmol/L-0.96 × 10-1 µmol/L for AHLs. The MFMP was applied to the analysis of fish juice and milk samples, and recoveries ranged from 83.10% to 90.74% with relative standard deviation less than 5.1%. This study offered a novel strategy to fabricated AHLs fluorescence probe with great potential for wide-ranging application in agri-food products.


Assuntos
Acil-Butirolactonas/análise , Carbono/química , Peixes , Corantes Fluorescentes/química , Leite/química , Impressão Molecular , Pontos Quânticos/química , Animais , Imãs/química , Polímeros/síntese química
8.
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
9.
Int J Nanomedicine ; 15: 2605-2615, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32368043

RESUMO

Objective: This paper introduces a simple one-step and ultra-fast method for synthesis of highly photothermally active polypyrrole-coated gold nanoparticles. The synthesis process is so simple that the reaction is very fast without the need for any additives or complicated steps. Methodology: Polypyrrole-coated gold nanoparticles (AuPpy NPs) were synthesized by reacting chloroauric acid (HAuCl4) with pyrrole (monomer) in aqueous medium at room temperature. These nanoparticles were characterized by UV-visible-NIR spectrometry, transmission electron microscopy (TEM), AC conductivity, zeta sizer and were evaluated for dark cytotoxicity and photocytotoxicity using human hepatocellular carcinoma (HepG2) cell line as a model for cancer cells. Results: The synthesized AuPpy NPs showed a peak characteristic for gold nanoparticles (530-600 nm, molar ratio dependent) and a wide absorption band along the visible-NIR region with intensity about triple or even quadruple that of polypyrrole synthesized by the conventional FeCl3 method at the same concentration and under the same conditions. TEM imaging showed that the synthesized AuPpy NPs were composed of spherical or semi-spherical gold core(s) of about 4-10 nm coated with distinct layer(s) of polypyrrole seen either loosely or in clusters. Mean sizes of the synthesized nanoparticles range between ~25 and 220 nm (molar ratio dependent). Zeta potentials of the AuPpy NPs preparations indicate their good colloidal stability. AC conductivity values of AuPpy NPs highly surpass that of Ppy prepared by the conventional FeCl3 method. AuPpy NPs were non-toxic even at high concentrations (up to 1000 µM pyrrole monomer equivalent) under dark conditions. Unlikely, light activated the photothermal activity of AuPpy NPs in a dose-dependent manner. Conclusion: This method simply and successfully synthesized AuPpy NPs nanoparticles that represent a safe alternative photothermally active multifunctional tool instead of highly toxic and non-biodegradable gold nanorods.


Assuntos
Materiais Revestidos Biocompatíveis/química , Ouro/química , Luz , Nanopartículas Metálicas/química , Polímeros/química , Pirróis/química , Temperatura , Morte Celular , Cloretos/química , Condutividade Elétrica , Compostos de Ouro/química , Células Hep G2 , Humanos , Nanopartículas Metálicas/ultraestrutura , Tamanho da Partícula , Polímeros/síntese química , Pirróis/síntese química , Espectrofotometria Ultravioleta , Eletricidade Estática
10.
J Chromatogr A ; 1622: 461131, 2020 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-32381301

RESUMO

A carbazolic conjugated microporous polymer (designated as CZ-CMP) was successfully synthesized through Scholl reaction of carbazole with 1, 3, 5-triphenylbenzene. The CZ-CMP was characterized by FT-IR spectrum, X-ray diffraction, nitrogen sorption isotherms, and scanning electron microscopy. The characterization results showed that the CZ-CMP had a spherical structure with high surface area and good microporosity. Its adsorption performance was investigated by applying it as an adsorbent for the solid phase extraction (SPE) of phenyl urea herbicides (PUHs) (metoxuron, chlortoluron, isoproturon, monolinuron and buturon) from tea drinks samples prior to high performance liquid chromatographic detection. The CZ-CMP displayed high extraction efficiency for the PUHs, and the primary factors affecting the SPE efficiency including the type and volume of the eluent, sample solution pH, sample loading rate and sample volume were optimized. Under the optimized conditions, a good linear response for the analytes was observed in the range of 0.10-80.0 ng mL-1 with correlation coefficients (r) from 0.9937 to 0.9997. The limits of detection were measured to be in the range of 0.02-0.30 ng mL-1 and the limits of quantitation were in the range of 0.06-0.9 ng mL-1. The developed method was successfully applied for the determination of the five PUHs in four different kinds of drinks with the method recoveries between 83.7% and 118% and the relative standard deviations between 1.0% and 10%. Besides, the application potential of the CZ-CMP was evaluated by using it to extract different types of the organic compounds including some phthalate eaters (PAEs), chlorophenol (CPs), nitroimidazoles and polycyclic aromatic hydrocarbons (PAHs). The results indicated that the CZ-CMP had strong adsorption ability for the compounds with more hydrogen bonding sites and moderate hydrophobicity.


Assuntos
Herbicidas/isolamento & purificação , Compostos de Fenilureia/química , Polímeros/síntese química , Extração em Fase Sólida/métodos , Adsorção , Carbazóis/química , Cromatografia Líquida de Alta Pressão/métodos , Concentração de Íons de Hidrogênio , Compostos de Fenilureia/isolamento & purificação , Polímeros/química , Porosidade , Soluções , Espectroscopia de Infravermelho com Transformada de Fourier , Chá/química
11.
J Chromatogr A ; 1622: 461173, 2020 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-32450987

RESUMO

Poly(diphenylacetylene) having optically active anilide pendants (poly-1) were synthesized by the condensation reaction of an optically active carboxylic acid with a key precursor polymer containing amino (-NH2) groups, which was prepared by the polymerization of a phthalimide-protected diphenylacetylene monomer using WCl6-Ph4Sn as a catalyst, followed by phthalimide deprotection in the resulting polymer using hydrazine monohydrate. Poly-1 formed a preferred-handed helical conformation (h-poly-1) upon thermal annealing in DMF because of chirality of the pendant group. Poly-1 and h-poly-1 showed different chiral recognition abilities from the analogous poly(diphenylacetylene)s, having the corresponding optically active amide pendants, as chiral stationary phases (CSPs) for high-performance liquid chromatography. The resolution results with the h-poly-1-based CSP were much better than those with the poly-1-based CSP owing to the preferred-handed macromolecular helicity. Among the tested racemates, the h-poly-1-based CSP exhibited superior chiral recognition ability, especially toward binaphthyl compounds and chiral metal complexes.


Assuntos
Acetileno/análogos & derivados , Anilidas/síntese química , Cromatografia Líquida de Alta Pressão/métodos , Fenômenos Ópticos , Acetileno/química , Anilidas/química , Polimerização , Polímeros/síntese química , Polímeros/química , Estereoisomerismo
12.
J Chromatogr A ; 1622: 461147, 2020 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-32450989

RESUMO

Molecularly imprinted polymers coated magnetic particles (Fe3O4@MIPs) were prepared and used as adsorbents in solid phase extraction for efficient enantioseparation of racemic tryptophan (Trp) in aqueous medium. The amino-modified magnetic particles (Fe3O4-NH2) were first synthesized by one-pot hydrothermal method. Then the template molecules (L-Trp) were assembled on the surface of Fe3O4-NH2. Finally, Fe3O4@MIPs were prepared via a sol-gel method using L-Trp@Fe3O4-NH2 complex as matrix, 3-aminopropyltriethoxylsilane and n-octyltriethoxysilane as functional monomers. The as-prepared Fe3O4@MIPs were spherical with an average diameter about 149 ± 6.0 nm. The thickness of MIPs layer was approximately 3.5 ± 2.3 nm. The adsorption isotherms data of Fe3O4@MIPs toward L-Trp and D-Trp were well described by the Langmuir model. The maximum adsorption capacities of Fe3O4@MIPs for L-Trp and D-Trp were calculated to be 17.2 ± 0.34 mg/g and 7.2 ± 0.19 mg/g, respectively. The material exhibited good selectivity toward L-Trp with imprinting factor of 5.6. Excitingly, the enantiomeric excess (ee) of Trp in supernatant after adsorption of racemic Trp by Fe3O4@MIPs was as high as 100%. The result suggests that the imprinted caves in Fe3O4@MIPs are highly matched with L-Trp molecule in space structure and spatial arrangement of active functional groups. The work also demonstrates that sol-gel technology has great potential in preparation of MIPs for chiral separation.


Assuntos
Fenômenos Magnéticos , Impressão Molecular/métodos , Polímeros/síntese química , Triptofano/química , Triptofano/isolamento & purificação , Água/química , Adsorção , Compostos Férricos/química , Concentração de Íons de Hidrogênio , Polímeros/química , Reprodutibilidade dos Testes , Extração em Fase Sólida/métodos , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , Estereoisomerismo , Temperatura , Fatores de Tempo
13.
J Oleo Sci ; 69(6): 627-634, 2020 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-32404552

RESUMO

Present study has successfully synthesized melamine-based covalent organic polymers (MCOPs) and applied it as lipase carrier for recyclable esters hydrolysis and transesterification. The synthesized MCOPs are composed of dense nanosheet structures having a thickness of 3.5 nm. Three immobilization methods namely physical adsorption, cross-linking and carrier activation were employed to prepare the MCOPs-immobilized CRL. Cross-linked MCOPs-immobilized CRL (41.30 mg protein/g MCOPs) and carrier activated MCOPs-immobilized CRL (33.20 mg protein/g MCOPs) had higher enzyme loading as compared to physical absorb MCOPs-immobilized CRL (29.30 mg protein/g MCOPs). Nevertheless, physical absorb MCOPs-immobilized CRL demonstrated the highest esters hydrolysis (49.85 U) and transesterification (1.04 U) activities. Despite having the highest enzymatic activity, physical absorb MCOPs-immobilized CRL were not able to maintain its catalytic stability with more than 30% decreased in enzymatic activity during consecutive hydrolysis and transesterification activities. Meanwhile, cross-linked MCOPs-immobilized CRL demonstrated highest catalytic stability with highest enzymatic activities at the end of consecutive reactions. All the MCOPs-immobilized CRL can be easily recovered and reused through centrifugation with more than 85% of recovery rate.


Assuntos
Polímeros/química , Polímeros/síntese química , Triazinas/química , Triazinas/síntese química , Catálise , Enzimas Imobilizadas , Esterificação , Ésteres , Hidrólise , Lipase
14.
Pharm Res ; 37(5): 90, 2020 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-32382838

RESUMO

PURPOSE: The blood-brain barrier limits the application of idarubicin in the therapy of glioblastoma multiforme. Biodegradable, intracranial wafers with prolonged release may increase therapy efficiency. METHODS: Blank wafers, wafers containing 5% w/w and 10% w/w of idarubicin were formulated by solution casting from poly(L-lactide-co-glycolide) and poly(glycolide-co-ε-caprolactone). The following methods were used: NMR, GPC, DSC, FTIR, AFM, UV-VIS, and a viability and proliferation assay for idarubicin action (U87MG cell line). RESULTS: Wafers showed a surface with numerous immersions and hills. A lack of interactions between idarubicin and the copolymers was observed. The substance was entrapped in the matrix and released in two phases for all wafers with the appropriate bolus and maintenance dose. The burst effect was observed for all wafers, however, the biggest bolus for poly(L-lactide-co-glycolide) wafers containing 5% w/w of idarubicin was noted. The stable and steady degradation of poly(glycolide-co-ε-caprolactone) wafers containing 5% w/w of idarubicin ensures the most optimal release profile and high inhibition of proliferation. CONCLUSIONS: Copolymer wafers with idarubicin are an interesting proposition with great potential for the local treatment of glioblastoma multiforme. The release rate and dose may be regulated by the amount and kind of wafers for various effects.


Assuntos
Portadores de Fármacos/síntese química , Glioblastoma/tratamento farmacológico , Idarubicina/uso terapêutico , Polímeros/síntese química , Linhagem Celular Tumoral , Sobrevivência Celular , Liberação Controlada de Fármacos , Humanos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Tecnologia Farmacêutica/métodos
15.
Nat Commun ; 11(1): 1724, 2020 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-32265490

RESUMO

Vesicular photothermal therapy agents (PTAs) are highly desirable in photothermal therapy (PTT) for their excellent light-harvesting ability and versatile hollow compartments. However, up to now, the reported vesicular PTAs are generally self-assembled from small molecules like liposomes, and polymer vesicles have seldom been used as PTAs due to the unsatisfactory photothermal conversion efficiency resulting from the irregular packing of chromophores in the vesicle membranes. Here we report a nano-sized polymer vesicle from hyperbranched polyporphyrins with favorable photothermal stability and extraordinarily high photothermal efficiency (44.1%), showing great potential in imaging-guided PTT for tumors through in vitro and in vivo experiments. These excellent properties are attributed to the in situ supramolecular polymerization of porphyrin units inside the vesicle membrane into well-organized 1D monofilaments driven by π-π stacking. We believe the supramolecular polymerization-enhanced self-assembly process reported here will shed a new light on the design of supramolecular materials with new structures and functions.


Assuntos
Sobrevivência Celular/efeitos dos fármacos , Hipertermia Induzida/métodos , Nanopartículas/química , Fototerapia/métodos , Polímeros/química , Porfirinas/química , Animais , Dicroísmo Circular , Feminino , Humanos , Interações Hidrofóbicas e Hidrofílicas , Células MCF-7 , Membranas Artificiais , Camundongos , Camundongos Nus , Microscopia Eletrônica de Varredura , Simulação de Dinâmica Molecular , Células NIH 3T3 , Nanopartículas/uso terapêutico , Nanopartículas/ultraestrutura , Polimerização , Polímeros/síntese química , Polímeros/farmacocinética , Polímeros/uso terapêutico , Porfirinas/síntese química , Porfirinas/farmacocinética , Porfirinas/uso terapêutico , Ratos , Espectrometria de Fluorescência , Temperatura , Transplante Heterólogo
16.
Nat Commun ; 11(1): 1630, 2020 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-32242004

RESUMO

The high toughness of natural spider-silk is attributed to their unique ß-sheet secondary structures. However, the preparation of mechanically strong ß-sheet rich materials remains a significant challenge due to challenges involved in processing the polymers/proteins, and managing the assembly of the hydrophobic residues. Inspired by spider-silk, our approach effectively utilizes the superior mechanical toughness and stability afforded by localised ß-sheet domains within an amorphous network. Using a grafting-from polymerisation approach within an amorphous hydrophilic network allows for spatially controlled growth of poly(valine) and poly(valine-r-glycine) as ß-sheet forming polypeptides via N-carboxyanhydride ring opening polymerisation. The resulting continuous ß-sheet nanocrystal network exhibits improved compressive strength and stiffness over the initial network lacking ß-sheets of up to 30 MPa (300 times greater than the initial network) and 6 MPa (100 times greater than the initial network) respectively. The network demonstrates improved resistance to strong acid, base and protein denaturants over 28 days.


Assuntos
Polímeros/química , Seda/química , Animais , Fenômenos Biomecânicos , Interações Hidrofóbicas e Hidrofílicas , Polímeros/síntese química , Conformação Proteica em Folha beta , Aranhas
17.
Food Chem ; 321: 126690, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32244139

RESUMO

The current research article was reported the synthesis of a novel poly(3-hydroxy butyrate)-b-poly(vinyl benzyl xanthate) block copolymer (PHB-Xa) for vortex-assisted solid-phase microextraction of cobalt(II) and nickel(II) from canned foodstuffs prior to their determinations by flame atomic absorption spectrometry. The block copolymer was synthesized and characterized by nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy. Experimental variables affecting the extraction efficiency of the copolymer were optimized. Since the PHB-Xa block copolymers have a high π conjugate structure and hydrophobicity, the use of this adsorbent yielded quantitative results for the extraction of Ni(II) and Co(II). After optimization, the linearities for Ni(II) and Co(II) were 0.05-80 ng mL-1 and 0.2-100 ng mL-1, respectively. The limits of detection and the limits of quantification were in the range of 0.015-0.06 ng mL-1 and 0.05-0.2 ng mL-1, respectively. The method was successfully applied to determination of Ni(II) and Co(II) in canned foodstuffs prepared by microwave digestion.


Assuntos
Cobalto/isolamento & purificação , Análise de Alimentos/métodos , Níquel/isolamento & purificação , Polímeros/química , Microextração em Fase Sólida/métodos , Cobalto/análise , Contaminação de Alimentos , Alimentos em Conserva , Hidroxibutiratos/química , Limite de Detecção , Espectroscopia de Ressonância Magnética , Níquel/análise , Poliésteres/química , Polímeros/síntese química , Cloreto de Polivinila/química , Espectrofotometria Atômica/métodos , Espectroscopia de Infravermelho com Transformada de Fourier
18.
Int J Nanomedicine ; 15: 2131-2150, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32280211

RESUMO

Gene-based therapies have emerged as a new modality for combating a myriad of currently incurable diseases. However, the fragile nature of gene therapeutics has significantly hampered their biomedical applications. Correspondingly, the development of gene-delivery vectors is of critical importance for gene-based therapies. To date, a variety of gene-delivery vectors have been created and utilized for gene delivery. In general, they can be categorized into viral- and non-viral vectors. Due to safety issues associated with viral vectors, non-viral vectors have recently attracted much more research focus. Of these non-viral vectors, polymeric vectors, which have been preferred due to their low immunogenicity, ease of production, controlled chemical composition and high chemical versatility, have constituted an ideal alternative to viral vectors. In particular, biodegradable polymers, which possess advantageous biocompatibility and biosafety, have been considered to have great potential in clinical applications. In this context, the aim of this review is to introduce the recent development and progress of biodegradable polymers for gene delivery applications, especially for their chemical structure design, gene delivery capacity and additional biological functions. Accordingly, we first define and categorize biodegradable polymers, followed by describing their corresponding degradation mechanisms. Various types of biodegradable polymers resulting from natural and synthetic polymers will be introduced and their applications in gene delivery will be examined. Finally, a future perspective regarding the development of biodegradable polymer vectors will be given.


Assuntos
Materiais Biocompatíveis/química , Técnicas de Transferência de Genes , Polímeros/química , Cátions , Terapia Genética/métodos , Humanos , Polímeros/síntese química
19.
AAPS PharmSciTech ; 21(4): 121, 2020 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-32337630

RESUMO

Multidrug resistance is the major problem in cancer treatment nowadays. Compounds from plants are the new targets to solve this problem. Quercetin (QCT), quercetrin (QTR), and rutin (RUT) are potential anticancer flavonoids but their poor water solubility leads to less efficacy. In this study, the polymeric micelles of benzoylated methoxy-poly (ethylene glycol)-b-oligo(ε-caprolactone) or mPEG-b-OCL-Bz loading with the flavonoids were prepared to solve these problems. The flavonoid-loaded micelles showed an average size of 13-20 nm and maximum loading capacity of 35% (w/w). The release of QCT (21%, 3 h) was lower than that of QTR (51%, 3 h) and RUT (58%, 3 h). QCT (free and micelle forms) exhibited significantly higher cytotoxicity against P-glycoprotein-overexpressing leukemia (K562/ADR) cells than QTR and RUT (p < 0.05). The results demonstrated that QCT-loaded micelles effectively reversed cytotoxicity of both doxorubicin (multidrug resistant reversing (δ) values up to 0.71) and daunorubicin (δ values up to 0.74) on K562/ADR cells. It was found that QCT-loaded micelles as well as empty polymeric micelles inhibited P-gp efflux of tetrahydropyranyl Adriamycin. Besides, mitochondrial membrane potential was decreased by QCT (in its free form and micellar formation). Our results suggested that the combination effects of polymeric micelles (inhibiting P-gp efflux) and QCT (interfering mitochondrial membrane potential) might be critical factors contributing to the reversing multidrug resistance of K562/ADR cells by QCT-loaded micelles. We concluded that QCT-loaded mPEG-b-OCL-Bz micelles are the attractive systems for overcoming multidrug-resistant cancer cells.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/síntese química , Antineoplásicos/síntese química , Flavonoides/síntese química , Micelas , Polietilenoglicóis/síntese química , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/farmacologia , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Relação Dose-Resposta a Droga , Flavonoides/farmacologia , Humanos , Células K562 , Polietilenoglicóis/farmacologia , Polímeros/síntese química , Polímeros/farmacologia , Solubilidade
20.
Top Curr Chem (Cham) ; 378(2): 31, 2020 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-32146596

RESUMO

DNA nanotechnology, based on sequence-specific DNA recognition, could allow programmed self-assembly of sophisticated nanostructures with molecular precision. Extension of this technique to the preparation of broader types of nanomaterials would significantly improve nanofabrication technique to lower nanometer scale and even achieve single molecule operation. Using such exquisite DNA nanostructures as templates, chemical synthesis of polymer and inorganic nanomaterials could also be programmed with unprecedented accuracy and flexibility. This review summarizes recent advances in the synthesis and assembly of polymer and inorganic nanomaterials using DNA nanostructures as templates, and discusses the current challenges and future outlook of DNA templated nanotechnology.


Assuntos
DNA/química , Compostos Inorgânicos/química , Nanoestruturas/química , Nanotecnologia/métodos , Polímeros/química , Animais , Lipossomos/química , Polímeros/síntese química
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