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1.
Food Chem ; 457: 140114, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38909453

RESUMO

The aim of this study was to develop a practical orbital shaker-assisted magnetic solid phase extraction (OSA-MSPE) method for the determination of lead by FAAS. A new magnetic poly linoleic acid-polystyrene-polydimethylsiloxane (PSt-PLina-PDMS) hydrophobic graft copolymer was synthesized and characterized by NMR, FT-IR, SEM-EDX, DSC, TGA, BET and used as adsorbent for the extraction of Pb (II). This adsorbent can be used at least 50 times without any decrease of its adsorption properties for the adsorption and elution of analyte ions. Several analytical parameters including pH, adsorbent amount, sample volume, shaking time, etc. were optimized. Multivariate optimization was used for the investigation of different parameters. The linear range at optimum operating condition was 1.7-84 µg L-1. The limit of detection (LOD) and limit of quantification (LOQ) were 0.5 µg L-1, 1.7 µg L-1, respectively. Intraday and interday relative standard deviation (RSD %), enhancement factor (EF) and adsorbent capacity were found as 1.9%, 3.3%, 166.7, 50 mg g-1, respectively. OSA-MSPE method was tested with certified reference materials including LGC-6010 (Hard Drinking Water), NCS ZC73032 Celery and CS-M-3 Control Sample Microelements in Mushroom Powder for the accuracy. Experimental results for lead were confirmed with certified values. Present method was successfully applied to various liquid and solid food samples. The OSA-MSPE method has some important features such as selective, sensitive, low LOD, LOQ and RSD, pre-concentration factor (PF) and high enhancement factor (EF). High tolerance limits against matrix ions were achieved.

2.
Front Chem ; 12: 1367451, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38549839

RESUMO

This work refers to the synthesis and characterization of poly (3-hydroxybutyrate)-b-oligo (2-ethyl oxazoline) (oligoEtOx). Cationic ring-opening polymerization of 2-ethyl oxazoline yielded poly (2-ethyl oxazoline) (oligoEtOx) with a hydroxyl end. Carboxylic acid-terminated PHB was reacted with oligoEtOx via dicyclohexylcarbodiimide chemistry to obtain PHB-b-oligoEtOx conjugates. The obtained PHB-b-oligoEtOx conjugates were successfully characterized by 1H- and 13C NMR, FTIR, DSC, and size exclusion chromatography. PHB-b-oligoEtOx conjugates can be promising biologic active materials.

3.
Food Chem ; 446: 138871, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38432133

RESUMO

A new graft copolymer composed of polystyrene and polylinoleic acid (PLinas) with the sodium salt of iminodiacetate (Ida) was synthesized and used as an adsorbent. The vortex-assisted dispersive solid-phase micro-extraction (VA-dSPµE) method was used for the extraction and pre-concentration of chromium. Multivariate methodologies, such as factorial design and 3D surface plots, were applied for screening and optimizing effective extraction parameters. The influence of diverse analytical parameters, such as pH, sample volume, and interfering ions, on the extraction of chromium was studied. The calibration standard curve exhibited a linear range from 0.01 to 0.50 µg L-1. The relative standard deviation and limit of detection were found to be 1.65 % and 0.003 µg L-1, respectively. Extraction recoveries were found in the range of 96 to 99 % by using certified reference materials (CRMs). The adsorbent capacity of PLinas-Ida was found to be 112 mg g-1. The VA-dSPµE method demonstrated its effectiveness in the pre-concentration and determination of chromium within samples of foodstuffs by graphite furnace-atomic absorption spectrometry (GF-AAS).


Assuntos
Cromo , Extração em Fase Sólida , Extração em Fase Sólida/métodos , Polímeros/química , Microextração em Fase Sólida/métodos , Espectrofotometria Atômica/métodos
4.
Foods ; 12(19)2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37835273

RESUMO

Background: Cadmium (Cd) is a very toxic and carcinogenic heavy metal even at low levels and it is naturally present in water as well as in food. Methods: A new polyvinyl benzyl xanthate (PvbXa) was synthesized and used as a new adsorbent in this work. It contains pendant sulfide groups on the main polystyryl chain. Using this new adsorbent, PvbXa, a vortex-assisted dispersive solid-phase microextraction (VA-dSPµE) procedure was developed for the determination of cadmium from food and water samples via flame atomic absorption spectrophotometry (FAAS). Synthesized PvbXa was characterized by 1H Nuclear magnetic resonance (NMR) Spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Photoelectron Spectroscopy (XPS). The different parameters of pH, sample volume, mixing type and time, sorbent amount, and eluent time were optimized using standard analytical methods. Results: The optimized method for assessment of Cd in food and water samples shows good reliability. The optimum conditions were found to be a 0.20-150 µg L-1 linear range, 0.06 µg L-1 LOD, 0.20 µg L-1 LOQ, 4.3 RSD %, and a preconcentration factor of 160. Conclusions: The statistically experimental variables were utilized using a central composite design (CCD). The present method is a low-cost, simple, sensitive, and very effective tool for the recovery of Cd.

5.
Environ Sci Pollut Res Int ; 30(33): 79904-79915, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37286840

RESUMO

As a novel adsorbent, an opioid silver-morphine-functionalized polypropylene was synthesized through a one-pot reaction at room temperature and successfully used for the simple one-pot photocatalytic degradation catalyst of methyl orange removal from wastewater. UV spectral analysis reveals a special reference to the excitation of surface plasmon resonance as the main characteristic of the polymer-Ag nanocomposite in toluene solution peak at 420 nm in AgPP-mrp catalyst. The 1H NMR spectrum showed no sign of Ag NP peaks revealing small size distribution in the channels of morphine-functionalized polypropylene polymer. The morphology of silver nanoparticle-doped polymer through scanning electron microscopy (SEM-EDX) reveals PP-mrp with continuous matrix and Ag NPs (0.87 wt%). Furthermore, photocatalytic degradation of methyl orange was investigated on AgPP-mrp catalyst spectrophotometrically under solar irradiation in waste effluent, demonstrating high degradation efficiency. According to experimental findings, silver nanoparticles (AgPP-mrp) achieved high degradation capacities of 139 mg/g equivalent to 97.4% of photodegradation in a little period of time (35 min), as associated with previously stated materials and follow pseudo-second-order kinetic degradation tail of a high regression coefficient (R2 = 0.992). The suggested techniques offer a linear reaction for MO over the pH range of 1.5 to 5 and a degradation temperature of 25 to 60 °C. Central composite design and response surface methodology statistics recommend pH of the reaction medium and time as important variables for methyl orange degradation on AgPP-mrp photocatalytic. AgPP-mrp on the photocatalytic phenomenon based on heterojunction catalytic design producing electron holes (e-), as well as superoxides for the successful degradation of methyl orange.


Assuntos
Nanopartículas Metálicas , Nanocompostos , Nanopartículas Metálicas/química , Prata/química , Polipropilenos , Morfina , Nanocompostos/química , Catálise
6.
Food Chem ; 425: 136523, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37295209

RESUMO

A new polyoleic acid-polystyrene (PoleS) block/graft copolymer was synthesized and applied as adsorbent for ultrasound assisted dispersive solid phase microextraction (UA-DSPME) of Sb(III) in different bottled beverages and analysis using hydride generation atomic absorption spectrometry (HGAAS). Adsorption capacity of the PoleS was 150 mg g-1. Several sample preparation parameters such as sorbent amount, solvent type, pH, sample volume and shaking time were optimized (based on central composite design (CCD) approach) and evaluated in respect to the recovery of Sb(III). The method revealed a high tolerance limit of matrix ions presence. Under optimized conditions, linearity range, the limit of detection, the limit of quantitation, extraction recovery, enhancement factor, preconcentration factor were 5-800 ng L-1, 1.5 ng L-1, 5.0 ng L-1, 96%, 82, 90, respectively. Accuracy of the UA-DSPME method was confirmed based on different certified reference materials and standard addition method. Factorial design was utilized to estimate the influences of variables of recovery of Sb(III).


Assuntos
Microextração em Fase Líquida , Microextração em Fase Sólida , Microextração em Fase Sólida/métodos , Poliestirenos/química , Espectrofotometria Atômica/métodos , Bebidas/análise , Polímeros/análise , Limite de Detecção
7.
J Microencapsul ; 40(3): 197-215, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36881484

RESUMO

Current artificial ligaments based on polyethylene terephthalate (PET) are associated with some disadvantages due to their hydrophobicity and low biocompatibility. In this study, we aimed to modify the surface of PET using polyethylene glycol (PEG)-terminated polystyrene (PS)-linoleic nanoparticles (PLinaS-g-PEG-NPs). We accomplished that BMP-2 in two different concentrations encapsulated in nanoparticles with an efficiency of 99.71 ± 1.5 and 99.95 ± 2.8%. While the dynamic contact angle of plain PET surface reduced from 116° to 115° after a measurement periods of 10 s, that of PLinaS-g-PEG-NPs modified PET from 80° to 17.5° within 0.35 s. According to in vitro BMP2 release study, BMP-2 was released 13.12 ± 1.76% and 45.47 ± 1.78% from 0.05 and 0.1BMP2-PLinaS-g-PEG-NPs modified PET at the end of 20 days, respectively. Findings from this study revealed that BMP2-PLinaS-g-PEG-NPs has a great potential to improve the artificial PET ligaments, and could be effectively applied for ACL reconstruction.


Assuntos
Ligamento Cruzado Anterior , Nanopartículas , Ligamento Cruzado Anterior/cirurgia , Polietilenotereftalatos , Proteína Morfogenética Óssea 2
8.
Food Chem ; 403: 134475, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36358104

RESUMO

A novel one step route for the synthesis of tannic acid, lipoic acid and menthol functionalized polyvinyl chloride, PVC, (PVC-Tann, PVC-Lip, PVC-Mnt) and chlorinated polypropylene, PP-Cl, (PP-Mnt, PP-Lip) was applied imparting antioxidative properties to the newly-formed materials. The resulting modified polymers were characterized by stress-strain mechanical measurement, 1H NMR, gel permeation chromatography (GPC) and thermogravimetric (TGA) analysis. Linseed oil, owing to its high linolenic acid content, was used to track the autoxidation process. The chloride functional groups were reacted with the hydroxyl/carboxylic acid of the natural compounds in the presence of a base. Linseed oil was poured into the natural compound functionalized PVC covered Petri dish to undergo autoxidation under white light. Each of the PVC- and PP-Cl-based polymers was active in delaying autoxidation. The PP-Mnt series and PP-Lip polymers all delayed autoxidation by 8 days over the PP-Cl precursor material. The autoxidation process was further confirmed by monitoring peroxide formation in the exposed linseed oil samples through differential scanning calorimeter (DSC) analysis.


Assuntos
Ácido Tióctico , Cloreto de Vinil , Cloreto de Polivinila/química , Polipropilenos , Mentol , Taninos , Óleo de Semente do Linho , Polímeros/química
9.
Food Chem ; 395: 133607, 2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-35802978

RESUMO

A new and novel poly(vinyl benzyl dithiocarbonate-dimethyl amino ethyl methacrylate) block copolymer (Pvb-DMA-Xa) as adsorbent was synthesized for the vortex-assisted dispersive solid phase microextraction (VA-DSPME) of patulin from apple products and dried fruits using Uv-visible spectrophotometer. The characterization of synthesized Pvb-DMA-Xa block copolymer was performed with Fourier Transform Infrared spectroscopy (FTIR-ATR) technique. Analytical characteristics such as pH, sorbent amount, adsorption time, eluent type and its volume, desorption time and adsorption capacity were optimized. Limit of detection (3Sb/m) and limit of quantitation (10Sb/m) were found 0.3 and 1.0 ng mL-1. Linear dynamic range (LDR), relative standard deviation (RSD) and recovery values were found in the range of 1-30 ng mL-1, 2.1-2.7 % and 93.5-97.3 %, respectively. Enhancement factor (EF) was found 193. The accuracy of the method was confirmed with standard addition method and analyzing of samples by reference method.


Assuntos
Malus , Patulina , Frutas/química , Limite de Detecção , Malus/química , Metacrilatos , Patulina/análise , Polímeros/química , Microextração em Fase Sólida/métodos
10.
Food Chem ; 393: 133464, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-35751221

RESUMO

A newly synthesized xanthate functionalized chlorinated polypropylene (PP-Xa) was used as adsorbent for the orbital shaker based on dispersive solid phase microextraction (OS-DSPME) of caffein from several tea, coffee, energy drink, coca-cola and chocolate samples using UV-vis. spectrophotometer. Synthesized PP-Xa was characterized using Fourier Transform Infrared spectroscopy (FTIR-ATR) and nuclear magnetic resonance spectroscopy (1H NMR). Various parameters like pH, PP-Xa amount, extraction time, type of eluent and its volume were optimized. Linear range, detection limit (LOD), limit of quantification (LOQ), relative standard deviation (RSD), recovery values, and enrichment factor (EF) were found 90-1000 µgL-1, 27.3 µg L-1, 90 µg L-1, 1.9-2.6%, 98 ± 2%, and 167, respectively. Adsorption capacity of PP-Xa was found 271.9 mg g-1. Standard addition and reference method were used for confirm the accuracy of present method.


Assuntos
Cafeína , Microextração em Fase Sólida , Bebidas/análise , Limite de Detecção , Polipropilenos , Extração em Fase Sólida/métodos , Microextração em Fase Sólida/métodos
11.
J Biomater Appl ; 36(9): 1599-1616, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35043697

RESUMO

Breast cancer is a malignant tumor, which has derived from cells of the breast. Further, a relatively rapid metastasis, and resistance development against all the conventional drug combinations are major clinical issues in breast cancer patients as well as limitations like toxicity, genetic mutation, and metastasis make difficult the use of conventional therapy methods such as chemotherapy, radiotherapy, and local surgery. Therefore, considering the urgent needs, and high death rate in breast cancer cases, the development of new diagnosis and treatment regimens which diagnosed at the early stage and protected normal tissues required for clinical applications. Recently, the combination of tumor diagnosis and treatment within a single platform is a novel perspective, and magnetic nanoparticles are potential candidate owing to their low toxic effect, biocompatibility, biological degradability, superior magnetic properties, and targeting ability to overcome the problems of conventional diagnosis and therapy techniques. Considering these restrictions and requirements, the goal of this research was to investigate the potential of an innovative theranostic agent, which is soybean oil-based polystyrene (PS)-g-soybean oil graft copolymer containing AgNPs (PS-Agsbox) for treatment and MRI-based diagnosis of cancer. Herein, we designed targeted magnetic PS-Agsbox nanoparticles carrying thymoquinone (TQ) that is known for its anticancer potential against breast cancer, and herceptin (HER), which is to bind to the HER2 receptor protein on the surface of HER2-positive tumor cells, and acts by blocking the effects of it. We have successfully demonstrated selective binding, effective uptake of HER-conjugated magnetic PS-Agsbox nanoparticles into MDA-MB-231 (human breast carcinoma cells, a HER2-underexpressing cell line) and SKBR-3 (human breast cancer cells, a HER2-overexpressing breast cancer cell line) cell lines while no effect against L929 (mouse fibroblast cell line). Moreover, the magnetic resonance (MRI) properties of HER-conjugated magnetic PS-Agsbox nanoparticles were also confirmed.


Assuntos
Neoplasias da Mama , Nanopartículas , Animais , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Feminino , Humanos , Camundongos , Nanopartículas/química , Nanopartículas/uso terapêutico , Poliestirenos/uso terapêutico , Medicina de Precisão , Óleo de Soja , Trastuzumab/uso terapêutico
12.
Food Chem ; 369: 130973, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34507087

RESUMO

Polystyrene-polyricinoleic acid copolymer containing silver nano particles (AgPSrici) was synthesized and used in separation of molybdenum from different aqueous and foodstuff samples during a dispersive-µ-solid phase extraction approach. The synthesized nano particles were verified using Fourier transform infraredspectroscopy. An electrothermal atomic absorption spectrometry has been used for measurement of the studied ions. AgPSrici amount pH, sample volume, elution solvent kind, and the time of extraction were the effective parameters that were optimized by one-variable-at-one-time method. Analytical data of the method was calculated and limit of detection, relative standard deviation, limit of quantification were 0.022 µg L-1, 2.9%, 150, and 0.066 µg L-1, respectively. The synthesized adsorption capacity was obtained 170 mg g-1.Accuracy of the method was studied by performing the method on certified reference materials and the presence of different interfering ions was studied. Molybdenum content of different water and foodstuffs was determined by the introduced method.


Assuntos
Microextração em Fase Sólida , Água , Limite de Detecção , Molibdênio , Poliestirenos , Prata , Extração em Fase Sólida , Espectrofotometria Atômica
13.
Int J Mol Sci ; 22(13)2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34281198

RESUMO

Reconstruction of nerve defects is a clinical challenge. Autologous nerve grafts as the gold standard treatment may result in an incomplete restoration of extremity function. Biosynthetic nerve conduits are studied widely, but still have limitations. Here, we reconstructed a 10 mm sciatic nerve defect in healthy rats and analyzed nerve regeneration in poly (ε-caprolactone) (PCL) conduits longitudinally divided by gold (Au) and gold-cobalt oxide (AuCoO) nanoparticles embedded in poly-propylene poly-ethylene glycol (PPEG) membranes (AuPPEG or AuCoOPPEG) and compared it with unmodified PPEG-membrane and hollow PCL conduits. After 21 days, we detected significantly better axonal outgrowth, together with higher numbers of activated Schwann cells (ATF3-labelled) and higher HSP27 expression, in reconstructed sciatic nerve and in corresponding dorsal root ganglia (DRG) in the AuPPEG and AuCoOPPEG groups; whereas the number of apoptotic Schwann cells (cleaved caspase 3-labelled) was significantly lower. Furthermore, numbers of activated and apoptotic Schwann cells in the regenerative matrix correlated with axonal outgrowth, whereas HSP27 expression in the regenerative matrix and in DRGs did not show any correlation with axonal outgrowth. We conclude that gold and cobalt-oxide nanoparticle modified membranes in conduits improve axonal outgrowth and increase the regenerative performance of conduits after nerve reconstruction.


Assuntos
Ouro/administração & dosagem , Nanopartículas Metálicas/administração & dosagem , Regeneração Nervosa/efeitos dos fármacos , Nervo Isquiático/efeitos dos fármacos , Animais , Cobalto/farmacologia , Feminino , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Ouro/farmacologia , Nanopartículas Metálicas/química , Regeneração Nervosa/fisiologia , Óxidos/farmacologia , Poliésteres/química , Poliésteres/farmacologia , Polietilenoglicóis/química , Polietilenoglicóis/farmacologia , Polipropilenos/química , Polipropilenos/farmacologia , Próteses e Implantes , Ratos , Ratos Wistar , Células de Schwann/efeitos dos fármacos , Células de Schwann/metabolismo , Nervo Isquiático/metabolismo
14.
Food Chem ; 359: 129923, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-33964654

RESUMO

A green and efficient analytical approach was reported for simultaneous preconcentration, and separation of Pb(II) and Cd(II) in water, vegetables, and barbecue samples by dispersive solid-phase microextraction prior to their determination using flame atomic absorption spectrometry. A new poly-3-hydroxy butyrate-polyvinyl triethyl ammonium chloride comb-type amphiphilic cationic block copolymer (PHBvbNCl) was synthesized and characterized. Main variables such as pH, sorbent amount, adsorption time, eluent type, desorption time, and sample volume were optimized. Detection limits and working ranges for Pb(II) and Cd(II) were 0.03 µg L-1, 0.15 µg L-1, 0.1-250 µg L-1 and 0.5-375 µg L-1, respectively. Enhancement factor for Pb (II) and Cd (II) were 114 and 98. The adsorption capacity of PHBvbNCl for Pb(II) and Cd(II) was 175.2 mg g-1 and 152.9 mg g-1. After the accuracy of the method was confirmed by the analysis of certified reference materials, it was successfully applied to real samples. Finally, the analytical performance of the present method was compared with other methods.


Assuntos
Cádmio/análise , Chumbo/análise , Adsorção , Extração em Fase Sólida , Espectrofotometria Atômica , Água/química
15.
Sci Rep ; 11(1): 5481, 2021 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-33750835

RESUMO

We synthesized the poly(methyl methacrylate-co-2-aminoethyl methacrylate (PMaema) amphiphilic copolymer in a form of solid phase adsorbent. Then it was used for separation, preconcentration and determination of trace amount of As(III) ions from foods and waters with hydride generation atomic absorption spectrometry. The PMaema was characterized by fourier transform infrared spectrometer and nuclear magnetic resonance spectrometer. The adsorption of As(III) to the PMaema was also supported using computational chemistry studies. The experimental parameters (pH, PMaema amount, adsorption time and ethanol volume) were optimized using a three-level Box-Behnken design with four experimental factors. We observed linear calibration curve for the PMaema amount in the 10-500 ng L-1 range (R2 = 0.9956). Limit of detection, preconcentration factor and sorbent capacity of PMaema were equal to 3.3 ng L-1, 100 and 75.8 mg g-1, respectively. The average recoveries (spiked at 50 ng L-1) changes in the range of 91.5-98.6% with acceptable relative standard deviation less than 4.3%. After validation studies, the method was successfully applied for separation, preconcentration and determination of trace amount of As(III) from foods and waters.

16.
J Biomater Appl ; 36(3): 385-405, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33530824

RESUMO

Nosocominal infections associated with biofilm formation on urinary catheters cause serious complications. The aim of this study was to investigate the feasibility of the polyurethane (PU) catheter modified with tetracycline hydrochloride (TCH) attached Ag nanoparticles embedded PolyRicinoleic acid-Polystyrene Nanoparticles (PU-TCH-AgNPs-PRici-PS NPs) and the influence on antimicrobial and antibiofilm activity of urinary catheters infected by Escherichia coli and Staphylococcus aureus. For this purpose, AgNPs embedded PRici graft PS graft copolymers (AgNPs-PRici-g-PS) were synthesized via free radical polymerization and characterized by FTIR, HNMR and DSC. AgNPs-PRici-PS NPs were prepared and optimized by the different parameters and the optimized size of nanoparticle was found as about 150 ± 1 nm. The characterization of the nanoparticles and the morphological evaluation were carried out by FTIR and SEM. Short term stability of nanoparticles was realised at 4°C for 30 days. In vitro release profiles of TCH and Ag NPs were also investigated. The formation of biofilm on PU modified TCH-Ag NPs-PRici-PS NPs, was evaluated and the biocompatibility test of the nanoparticles was realized via the mouse fibroblast (L929) and mouse urinary bladder cells (G/G An1). This is the first time that TCH-AgNPs-PRici-PS NPs used in the modification of PU catheter demonstrated high antimicrobial and antibiofilm activities against the urinary tract infection.


Assuntos
Antibacterianos/administração & dosagem , Infecções Relacionadas a Cateter/prevenção & controle , Poliestirenos/química , Ácidos Ricinoleicos/química , Prata/administração & dosagem , Infecções Urinárias/prevenção & controle , Animais , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Catéteres/efeitos adversos , Catéteres/microbiologia , Linhagem Celular , Portadores de Fármacos/química , Escherichia coli/efeitos dos fármacos , Escherichia coli/fisiologia , Camundongos , Nanopartículas/química , Prata/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia
17.
Food Chem ; 344: 128644, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33246682

RESUMO

This work focuses on the synthesis of novel tannin-functionalized polypropylene copolymers that are designed to inhibit the oxidation of vegetable oils for potential use as packaging materials. An empty glass Petri dish (control), a chlorinated polypropylene-coated glass Petri dish (control) and a series of the tannin-functionalized polypropylene coated glass Petri dishes overlaid with linseed oil were exposed to air and additional white light. Oligomerization of the oxidized linseed oil was assessed by measuring the flow properties of the exposed oil using a viscometer. The antioxidant effect of the tannic acid grafted polypropylene copolymers (PP-Tann) retarded oligomerization of the linseed oil. The molar mass of the linoleic acid overlaid onto the PP-Tann films was the lowest among the tested samples after each time period indicating that tannin-grafted polypropylene may be a promising packaging material for vegetable oils.


Assuntos
Antioxidantes/química , Embalagem de Alimentos , Polipropilenos/química , Polipropilenos/síntese química , Taninos/química , Técnicas de Química Sintética , Oxirredução , Óleos de Plantas
18.
Food Chem ; 333: 127504, 2020 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-32679416

RESUMO

The aim of this study is to extract zinc and manganese from foods and vegetables using an amphiphilic copolymer adsorbent, poly(styrene)-co-2-vinylpyridine which was synthesized via reversible addition fragmentation chain transfer (RAFT) polymerization from styrene and 2-vinyl pyridine in the presence of a trithiocarbonate and 2,2'-azo-bis isobutyro nitrile (AIBN) in toluene solution under argon at 80 °C. Fourier Transform Infrared (FTIR) and proton nuclear magnetic resonance (1H NMR) spectroscopy were used in the characterization of the obtained copolymer. Under the optimum conditions, several validation variables such as uncertainty measurement, selectivity, robustness, precisions, matrix effects and accuracy were investigated. Taking an adsorption time of 15 min, detection limits of 0.04 µg L -1 and 0.2 µg L-1and 7.9 µg L-1and enrichment factors of 145 and 110 were obtained for Mn(II) and Zn(II), respectively.The method was successfully applied to the analysis of Mn(II) and Zn(II) in foods and vegetables.


Assuntos
Manganês/isolamento & purificação , Poliestirenos/química , Polivinil/química , Extração em Fase Sólida/métodos , Verduras/química , Zinco/isolamento & purificação , Adsorção , Espectroscopia de Ressonância Magnética , Manganês/análise , Polimerização , Extração em Fase Sólida/instrumentação , Espectroscopia de Infravermelho com Transformada de Fourier , Zinco/análise
19.
J Biomater Sci Polym Ed ; 31(12): 1580-1603, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32460649

RESUMO

Among many different types of fabricated nanoparticles, magnetic iron oxide nanoparticles (MNPs) have unique physical and chemical properties and have been widely used due to theirs enhanced permeability and retention effect for biomedical applications. The incorporated theranostic MNPs into biopolymer coatings are currently particular interest to investigators in the fields of nanobiomedicine because of efficiently delivering of various drugs, genes and providing imaging properties. Hepatocellular carcinoma (HCC) is the most prevalent reason of cancer-related deaths, makes it one of the worst malignant tumors in the world. Because, there is a lack of effective treatment methods for HCC, aforementioned magnetic carrier technology with recent innovations could be a promising tool in HCC diagnosis and treatment. Therefore, this study proposes a novel fatty-acid-based polymeric magnetic nanoprobe for diagnosis of hepatocellular tumors using polyethylene glycol (PEG)-terminated polystyrene (PS)-linoleic copolymer coated magnetic iron oxide nanoparticles. MNPs were synthesized by a co-precipitation method and were subsequently coated with a copolymer containing PEG group as termini. Fifty-nanometer-sized MNPs were incorporated into the core of PLinaS-g-PEG nanoparticles. The morphology and size distribution of the bare and magnetic PLinaS-g-PEG were determined by transmission electron microscopy (TEM), and dynamic light scattering (DLS), respectively. MTT and flow cytometry assays showed that PLinaS-g-PEG MNPs demonstrated ultrasentive apoptotic behavior against cancerous cell line, i.e. HepG2 in the culture plate when the fatty acid-containing polymer coated MNPs showed no adverse effect on L929 cell growth. The localization, and accumulation in hepatocytes of PLinaS-g-PEG MNPs without specific targeting ligand was confirmed by fluorescence and confocal microscopy. Therefore, PLinaS-g-PEG MNPs may be potentially used as a unique candidate for diagnosis of hepatocellular carcinomas.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Nanopartículas de Magnetita , Nanopartículas , Carcinoma Hepatocelular/diagnóstico por imagem , Meios de Contraste , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Polietilenoglicóis , Polímeros
20.
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
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