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1.
Food Chem ; 448: 138978, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38522291

RESUMO

In the current years of heightened focus on green chemistry and sustainable materials, this study delves into the untapped potential of hyaluronic acid (HA), chitin, and chitosan-prominent polysaccharides for groundbreaking applications. The primary aim is to effectively immobilize catalase enzymes onto matrices composed of chitosan, chitin, HA/chitin, and HA/chitosan. The rigorous investigation covers a spectrum of structural enhancements encompassing pH and temperature stability, thermal resilience, half-life extension, storage durability, reusability, and comprehensive FTIR analyses of the catalase immobilization. Notably, catalase activity demonstrated remarkable resilience on HA/chitin and HA/chitosan matrices, maintaining 73.80% and 79.55% efficacy even after 25 cycles. The introduction of covalent cross-linking between catalase and HA/chitin or HA/chitosan, facilitated by a cross-linking agent, significantly amplified stability and recycling efficiency. Consequently, the immobilized catalase showcases substantial promise across a spectrum of industrial applications, spanning from food and detergent production to bioremediation and diverse commercial processes. This underscores its pivotal role as a versatile and invaluable innovation in the realm of sustainable technologies.

2.
Biosensors (Basel) ; 13(7)2023 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-37504126

RESUMO

The fact that antioxidants scavenge free radicals in the human body and naturally treat many health problems that will occur in this way has increased the consumption of antioxidant-containing foods. However, consumption of artificially prepared antioxidants could cause cancer. Therefore, antioxidants from natural sources are preferred. Quercetin is an antioxidant present in natural samples. In this article, multi-walled carbon nanotubes (MWCNTs), a polymer composite (PC) consisting of a mixture of 15% (by mass) polystyrene (PST), 15% (by mass) polyacrylonitrile (PAN) and 70% (by mass) polyindole (PIN), and semiconducting BiVO4 were used to prepare electrodes, and then a photosensitive ITO/MWCNTs@PC@BiVO4-based sensor was fabricated for quercetin detection. Quercetin was analyzed via the photosensitive ITO/MWCNTs@PC@BiVO4 sensor in 0.1 M phosphate buffered saline (pH 7.4) solutions including various quercetin concentrations. The constructed quercetin sensor displayed a wide linear response between 10 and 200 µM and a limit of detection of 0.133 µM. The developed photosensitive ITO/MWCNTs@PC@BiVO4 demonstrated a high sensitivity (442 µA mM-1 cm-2), good reproducibility (relative standard deviation 3.6%), high selectivity and long-term stability (>49 days) towards quercetin sensing. The photoelectrochemical sensor was then applied to detection of quercetin in black tea as a real-life sample. Our study could lead to the development of novel photosensitive PC polyphenol sensors.


Assuntos
Nanotubos de Carbono , Polímeros , Humanos , Quercetina , Antioxidantes , Técnicas Eletroquímicas , Reprodutibilidade dos Testes , Eletrodos , Limite de Detecção
3.
Int J Biol Macromol ; 248: 125946, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37488000

RESUMO

Metal-organic frameworks (MOFs) have gained attention as a hopeful material for enzyme immobilization due to their advantageous characteristics, for instance, high surface area and easy construction conditions. Nonetheless, the confinement effect and competing coordination often lead to partial or complete inactivation of the immobilized enzymes. In this study, we present a novel strategy, the lactoferrin-boosted one-pot embedding approach, which efficiently connects enzymes with lactoferrin (LF) hybrid Graphene Oxide (GO)//Pt Nanoparticles/MOF-74 (referred to as enzyme@LF@rGO/PtNP@MOF-74). This approach demonstrates a high embedding efficiency. By employing a hybrid of LF and GO/Pt Nanoparticles as synchronous ligands for Zn-MOF-74, we provide a suitable environment for enzyme immobilization, resulting in enhanced enzymatic activity. The lipase@LF@rGO/PtNP@MOF-74 exhibits improved stability and resistance to organic solvents and significantly enhanced in thermal stability of the lipase@LF@rGO/PtNP@MOF-74 comparing to the free enzyme. The lipase@LF@rGO/PtNP@MOF-74 displayed excellent long-term storage stability, which could protect more than 80 % of the initial activity for 8 weeks. Besides, the lipase@LF@rGO/PtNP@MOF-74 had high reusability, which showed a high degree of activity (more than 75 %) after 20 cycles. As a bio-macromolecule, lactoferrin possesses bio-affinity, creating a favorable microenvironment for enzymes and minimizing the impact of external factors on their conformation and activity during bio-macromolecule utilization.


Assuntos
Biomimética , Lactoferrina , Enzimas Imobilizadas/metabolismo , Lipase/metabolismo
4.
Environ Res ; 213: 113590, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35690088

RESUMO

In our study, the electrochemical properties of a novel activated nanocomposite were studied with 2-dimensional graphitic carbon nitride/sodium dodecyl sulfate/graphene nanoplatelets on the screen-printed electrodes (2D-g-C3N4/SDS/GNPs/SPE). The as-fabricated sensor exhibited excellent electrochemical performance, including wide dynamic ranges from 0.03 to 1.0 and 1.0-13.5 µM with a low limit of detection (LOD) of 10.0 nM. The fabricated 2D-g-C3N4/SDS/GNPs/SPE electrode exhibited high sensitivity, stability, good reproducibility, reusability, and repeatability towards DOX sensing. It can be utilized in real samples, including human plasma and urine, with excellent correlations and coefficients of variation below 6.0%. Therefore, this study presents potential application values in sensing DOX with efficient performance. Finally, the accuracy was attested by comparison with high-performance liquid chromatography (HPLC) as the reference method, signalizing a good agreement.


Assuntos
Técnicas Eletroquímicas , Nanocompostos , Doxorrubicina/análise , Técnicas Eletroquímicas/métodos , Eletrodos , Humanos , Nanocompostos/química , Reprodutibilidade dos Testes
5.
Int J Biol Macromol ; 198: 175-186, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34973989

RESUMO

This study was planned to evolve the bioavailability and therapeutic efficiency of Gemcitabine (GEM) and 5-Fluorouracil with decreased side effects using MIL-100 nano-composite as carrier. Impregnation approach was used for encapsulation of 5-Fluorouracil alone and with GEM inside the MIL-100. The formed 5-Fluorouracil@MIL-100 and 5-Fluorouracil-GEM@MIL-100 were then coated with chitosan, sequentially chelated with iron(III) and conjugated with quercetin, eventually obtaining a multifunctional MIL-100 nanocarrier. The hybrid nanocarrier nascency was verified by different characterization results. pH-sensitive releases of 5-Fluorouracil and GEM were observed because of the inherent pH-dependent stability of MIL-100. Additionally, we evaluated the anti-cancer activity of these nanocarriers through WST-1 analysis and acridine orange staining in MCF-7 human breast cancer and HUVEC control cell lines. Our findings showed that all nanocarriers exhibited anti-cancer activity and induced apoptosis in MCF-7 cells. However, 5-Fluorouracil@MIL-100 and chitosan-coated 5-Fluorouracil@MIL-100 with quercetin were more effective than other nanocarriers in MCF-7 cells (p < 0.05). Moreover, we observed cytotoxicity in HUVEC cells due to the adverse side effects of chemotherapy drugs. However, chitosan coated nanocarriers with quercetin were less toxic on HUVEC cells at particularly 1 µg/mL. Therefore, MIL-100 could be used for a promising chemotherapeutic drugs delivery and chitosan coated drugs with quercetin could be useful for reducing toxicity on normal cells.


Assuntos
Quitosana
6.
Bioorg Chem ; 118: 105467, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34781115

RESUMO

Metal-organic structures (MOF), modern extremely proliferous materials consisting of metal ions and organic coordinating molecules, has become a promising biomedical material because of its unusual features, including great surface area, wide pore volume, flexible functionality and superior performance for drug loading. In the current investigation, Gemcitabine Hydrochloride (Gem), an anticancer drug, and Amygdalin (Amy) were loaded into a nanocomposite structure formed from bovine serum albumin (BSA) as a center and zeolytic imidazolate framework-8 (ZIF-8) as a pH sensitive protective coating. The formed BSA-Gem@ZIF-8 and BSA-Gem-Amy@ZIF-8 were successively coated by polydopamine, chelated by Au3+ and conjugated via gallic acid (GA), acquired ZIF-8 structure as a multifunctional nanocarrier at the end. It was confirmed by different characterization methods that the nanocarrier was successfully produced. Due to the nature of ZIF-8, pH dependent releases of BSA-Gem@ZIF-8/Dopa/GA and BSA-Gem-Amy@ZIF-8/Dopa/GA were observed in in vitro studies. Cytotoxicity and apoptotic effects of these nanocarriers were evaluated using WST-1 and acridine orange staining in MCF-7 human breast cancer and HUVEC control cell lines. In-vitro cytotoxicity studies showed that both BSA-Gem@ZIF-8/Dopa/GA and BSA-Gem-Amy@ZIF-8/Dopa/GA were more effective than gemcitabine alone in MCF-7 cells with less toxicity in HUVEC cells. Additionally, both pH-responsive nanocarriers induced more apoptotic cell death in MCF-7 cells. We therefore believe that the built multifunctional nanocarrier based on ZIF-8 could be an alternative therapeutic strategy the use of gemcitabine for cancer therapy.


Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Materiais Biocompatíveis/química , Desoxicitidina/análogos & derivados , Dopamina/química , Sistemas de Liberação de Medicamentos , Estruturas Metalorgânicas/química , Soroalbumina Bovina/química , Animais , Antimetabólitos Antineoplásicos/química , Bovinos , Proliferação de Células/efeitos dos fármacos , Desoxicitidina/química , Desoxicitidina/farmacologia , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Concentração de Íons de Hidrogênio , Células MCF-7 , Estrutura Molecular , Relação Estrutura-Atividade , Células Tumorais Cultivadas , Gencitabina
7.
Colloids Surf B Biointerfaces ; 204: 111788, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33932885

RESUMO

The metal-organic frameworks (MOF) have shown fascinating possibilities in biomedical applications, designing a multifunctional drug delivery system based on the MOF is important. In this study, 5-sulfosalicylic acid and boswellic acids (BAs) were loaded to the pH sensitive zeolitic imidazolate framework-8 (ZIF-8) nanocomposite containing bovine serum albumin (BSA) as the center. The ZIF layer acts as a capsule for the nontoxic storage of 5-sulfosalicylic acid and boswellic acids (BAs) under physiological conditions. The results of the characterization demonstrated the performance of the nanocarrier formation. The pH-sensitive drug release of 5-sulfosalicylic acid was detected due to the innate pH-dependent stability of ZIF-8. An effective pH-sensitive drug delivery system using a 5-sulfosalicylic acid/BSA@ZIF-8, and 5-sulfosalicylic acid/BSA/BAs@ZIF-8, in which the 5-sulfosalicylicacid is not free in physiological pH but it is released at acidic pH (5.0) has been fabricated. The best biocompatibility has been found in 5-sulfosalicylic acid/BSA/BAs@ZIF-8 comparing to the 5-sulfosalicylic acid/BSA, 5-sulfosalicylic acid /BSA/BAs, and 5-sulfosalicylic acid/BSA@ZIF-8. Additionally, 5-sulfosalicylic acid/BSA /BAs@ZIF-8 exhibited higher effectiveness than other compounds against the breast cancer cell line, MCF-7, with less toxicity. It is concluded from the results of the current study that the fabricated ZIF-8 based nanocarrier may potentially provide therapeutic effects on breast cancer cells.


Assuntos
Estruturas Metalorgânicas , Nanocompostos , Zeolitas , Benzenossulfonatos , Sistemas de Liberação de Medicamentos , Liberação Controlada de Fármacos , Humanos , Salicilatos , Triterpenos
8.
Int J Biol Macromol ; 182: 217-227, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33838186

RESUMO

Magnetic nanoparticles (MNPs) were modified by hyaluronic acid (HA). After the process of functionalization, two different strategies have been used to immobilize isocitrate dehydrogenases (IDH) on MNPs. In the first strategy, cross-linked enzyme aggregates were prepared. For this, firstly hyaluronic acid modified magnetic nanoparticles cross-linked enzyme fine aggregates of isocitrate dehydrogenases (IDH/HA/MNPs-CLEAs) were synthesized, and secondly bovine serum albumin (BSA) as co-feeder was used to synthesize the IDH/BSA/HA/MNPs-CLEAs. In the second strategy, the IDH was effectively immobilized on the HA/MNPs surface. The features of MNPs and its derivatives have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM), and zeta potential measurements. The activity and stability of IDH in IDH/HA/MNPs, IDH/HA/MNPs-CLEAs, and IDH/BSA/HA/MNPs-CLEAs were enhanced. Besides, the enzyme immobilized was readily separated via external magnet from the reaction medium and reused many times. The acquired findings indicate that HA/MNPs are a novel binder/support system to IDH, and IDH immobilized on this system can become a very important biocatalyst working with high accuracy and sensitivity for the determination of magnesium in drinking water and other biological solutions.


Assuntos
Ácido Hialurônico/química , Isocitrato Desidrogenase/química , Nanopartículas Magnéticas de Óxido de Ferro/química , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Isocitrato Desidrogenase/metabolismo , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
9.
Food Chem ; 349: 129127, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33561794

RESUMO

Metal-organic structures (MOFs) have been designed for a wide range of applications due to their high porosity, large surface area, and flexibility. For the first time in this work, the successful immobilization of α-amylase is confirmed by the use of ZIF-8 as easy and good support. The morphology, functional groups, and chemical composition of the support and immobilized α-amylase were tested using different methods such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermal gravimetric analysis (TGA). The enzymatic activities of the immobilized olibanum-bovine serum albumin@zeolitic imidazolate frameworks nanocomposite (OLB/BSA@ZIF-8)-α-amylase were compared with the free one. The pH and thermal stability of the OLB/BSA@ZIF-8-α-amylase were significantly enhanced compared to the free enzyme. The OLB/BSA@ZIF-8-α-amylase displayed excellent long-term storage stability, which could protect more than 90% of the initial activity for 8 weeks. Besides, the OLB/BSA@ZIF-8-α-amylase had high reusability, which showed a high degree of activity (more than 81%) after 20 cycles. This is the first study that uses OLB/BSA@ZIF-8 nanocomposite as immobilizing support for the immobilization of α-amylase. Improved catalytic efficiency (Vmax/Km) values, reusability, and storage stability of immobilized α-amylase can make it suitable in industrial and biotechnological applications.


Assuntos
Enzimas Imobilizadas/química , Estruturas Metalorgânicas/química , Nanocompostos/química , Soroalbumina Bovina/química , alfa-Amilases/química , Animais , Biocatálise , Biotecnologia , Bovinos , Estabilidade Enzimática , Enzimas Imobilizadas/metabolismo , Porosidade , Zeolitas/química , alfa-Amilases/metabolismo
10.
Water Sci Technol ; 82(9): 1912-1920, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33201854

RESUMO

The formation of heterojunction structures of semiconductors is one of the most important techniques to increase the photocatalytic efficiency of a photocatalyst. In this paper, Ag/Ag3VO4/TiO2 as a visible light response photocatalyst was prepared easily by a three step process including hydrothermal, precipitation and photoreduction. The Ag/Ag3VO4/TiO2 nanocomposites demonstrated clearly increased visible light absorption and photocatalytic efficiency in degradation of Rhodamine B. The degradation yield of Rhodamine B was detected 97.3% in 45 min under visible light. Compared with Ag3VO4, TiO2 and Ag3VO4/TiO2, Ag/Ag3VO4/TiO2 exhibited the highest efficiency owing to synergetic effect between Ag3VO4 and TiO2 and surface plasmon resonance effect of Ag nanoparticles. So, the Ag/Ag3VO4/TiO2 can be effectively used as an active photocatalyst under visible light and it depicts an ideal potential in elimination organic pollutants.


Assuntos
Poluentes Ambientais , Nanopartículas Metálicas , Catálise , Luz , Prata , Titânio
11.
Biosens Bioelectron ; 169: 112601, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32931991

RESUMO

Herein, we report a membraneless glucose and air photoelectrochemical biofuel cell (PBFC) with a visible light assisted photobioanode. Flavin adenine dinucleotide dependent glucose dehydrogenase (FADGDH) was immobilized on the combined photobioanode for the visible light assisted glucose oxidation (GCE|MWCNT|g-C3N4|Ru-complex|FADGDH) with a quinone mediated electron transfer. Bilirubine oxidase (BOx) immobilized on MWCNT coated GCE (GCE|BOx) was used as the cathode with direct electron transfer (DET). An improvement of biocatalytic oxidation current was observed by 6.2% due in part to the light-driven electron-transfer. The large oxidation currents are probably owing to the good contacting of the immobilized enzymes with the electrode material and the utilization of light assisted process. Under the visible light, the photobioanode shows an anodic photocurrent of 1.95 µA cm2 at attractively low potentials viz. -0.4 vs Ag/AgCl. The lower-lying conduction band of g-C3N4 as compared to Ru-complexes decreases the rate of hole and electron recombination and enhances the charge transportation. The bioanode shows maximum current density for glucose oxidation up to 6.78 µA cm-2 at 0.2 V vs Ag/AgCl at pH:7. The performance of three promising Ru-complexes differing in chemical and redox properties were compared as electron mediators for FADGDH. Upon illumination, the PBFC delivered a maximum power density of 28.5 ± 0.10 µW cm-2 at a cell voltage of +0.4 V with an open circuit voltage of 0.64 V.


Assuntos
Fontes de Energia Bioelétrica , Técnicas Biossensoriais , Eletrodos , Enzimas Imobilizadas/metabolismo , Glucose , Glucose 1-Desidrogenase/metabolismo , Oxirredução
12.
Biosens Bioelectron ; 141: 111385, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31185417

RESUMO

TiO2 inverse opal photonic crystals (IOPCs) were fabricated by using polystyrene template. TiO2 IOPCs based photoelectrochemical (PEC) biosensor was fabricated for the precise and stable detection of Heme without external irradiation. Then, the sensitization of TiO2 IOPCs was fulfilled with CdS quantum dots (QDs) by SILAR method to form ITO-TiO2 IOPCs-CdS:Mn electrode, which in turn was used to construct a PEC biosensor. The uniform porous structure of IOPCs with a large surface area is conducive to the excellent electronic transmission and QDs deposition. Also, the energy level matching between the conduction bands of CdS QDs and TiO2 IOPCs widened the range of light absorption, allowing for electron injection from excited CdS QDs to TiO2 upon luminol chemiluminescence, which enhanced the photocurrent. Furthermore, when the red edge of the photonic stop band of TiO2 IOPCs overlapped with the band gap of TiO2, and chemiluminescence emission of luminol, a substantial photocurrent increment was observed due in part to the slow light effect. The biosensor possesses a large linear detection range of 0.063-4 mM with a LOD of 19 µM for H2O2. Also, xanthine oxidase activity was determined with a linear measurement range of 0.01-15 mU/mL. Our strategy opens a new horizon to IOPCs based and QDs sensitized PEC sensing, which could be more sensitive, convenient and inexpensive for clinical and biological analysis. As far as we know, the largest photocurrent generation by luminol chemiluminescence was observed thanks to the use of semiconducting hybrid IOPCs material even at 0 V.


Assuntos
Técnicas Biossensoriais/métodos , Peróxido de Hidrogênio/análise , Pontos Quânticos/química , Titânio/química , Xantina Oxidase/análise , Compostos de Cádmio/química , Cristalização , Técnicas Eletroquímicas/métodos , Transferência de Energia , Luz , Processos Fotoquímicos , Sulfetos/química
13.
Mater Sci Eng C Mater Biol Appl ; 101: 292-305, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31029323

RESUMO

A novel implant coating material containing graphene oxide (GO) and collagen (COL), and hydroxyapatite (HA) was fabricated with the aid of tannic acid by electrodeposition. The surface of Ti16Nb alloy was subjected to anodic oxidation, and then HA-GO coating was applied to Ti16Nb surface by cathodic method. Then, COL was deposited on the surface of the HA-GO coating by the biomimetic method. HA, HA-GO, HA-GO-COL coatings on the surface of the Ti16Nb alloy have increased the corrosion resistance by the formation of a barrier layer on the surface. For HA-GO-COL coating, the highest corrosion resistance is obtained due to the compactness and homogeneity of the coating structure. The contact angle of the bare Ti16Nb is approximately 65°, while the contact angle of the coated samples is close to 0°. Herein, the increased surface wettability is important for cell adhesion. The surface roughness of the uncoated Ti16Nb alloy was between 1 and 3 µm, while the surface roughness of the coated surfaces was measured between 20 and 110 µm. The contact between the bone and the implant has been improved. Graphene oxide-containing coatings have improved the antibacterial properties compared to the GO-free coating using S. aureus. The hardness and elastic modulus of the coatings were measured by the nanoindentation test, and the addition of GO and collagen to the HA coating resulted in an increase in strength. The addition of GO to the HA coating reduced the viability of 3 T3 fibroblast cells, whereas the addition of collagen to HA-GO coat increased the cell adhesion and viability.


Assuntos
Ligas/farmacologia , Materiais Revestidos Biocompatíveis/farmacologia , Colágeno/farmacologia , Durapatita/farmacologia , Galvanoplastia/métodos , Grafite/farmacologia , Compostos de Estanho/química , Células 3T3 , Animais , Corrosão , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/ultraestrutura , Camundongos , Testes de Sensibilidade Microbiana , Nanotubos/química , Nanotubos/ultraestrutura , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície , Compostos de Estanho/farmacologia , Difração de Raios X
14.
Colloids Surf B Biointerfaces ; 173: 58-68, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30266021

RESUMO

The cross-linked enzyme aggregates (CLEAs) have numerous economic advantages in the industrial bio catalysis. In the present study, the multi CLEAs containing protease, catalase, and lipase from the sunflower seeds using starch as a cofeeder as well as bovine serum albumin (BSA) are designed and prepared successfully. After optimization, multi CLEAs of enzyme have been prepared with ammonium sulfate (55% w/v), glutaraldehyde (100 mM), and 8 mg/mL of starch or 20 mg/mL of BSA. The activity recovery of protease, catalase, and lipase multi CLEAs-starch are 87, 61, and 60%, respectively. Whereas, CLEAs prepared with BSA are 74, 61, and 50% activity and multi CLEAs only 60, 44, and 41% of protease, catalase, and lipase, respectively. The multi CLEAs were used to catalyze the reactions for enhanced washing process. After adding multi CLEAs-starch, the stain removal percentage of detergents is enhanced by 83%.The present study reports a high stability, simplicity, low cost, and recyclability of the novel multi CLEAs from the sunflower seeds that make them efficient as a highly active biocatalysts in the biotechnological applications. We believe that these novel multi CLEAs present a new approach to the synthesis of multi enzyme biocatalysts from the cheap and friendly environmental sources.


Assuntos
Catalase/química , Helianthus/química , Lipase/química , Peptídeo Hidrolases/química , Proteínas de Plantas/química , Sementes/química , Sulfato de Amônio/química , Biocatálise , Catalase/isolamento & purificação , Corantes/isolamento & purificação , Reagentes de Ligações Cruzadas/química , Detergentes/química , Ensaios Enzimáticos , Glutaral/química , Helianthus/enzimologia , Cinética , Lipase/isolamento & purificação , Peptídeo Hidrolases/isolamento & purificação , Proteínas de Plantas/isolamento & purificação , Agregados Proteicos , Sementes/enzimologia , Soroalbumina Bovina/química , Amido/química
15.
Int J Biol Macromol ; 120(Pt B): 1533-1543, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30261255

RESUMO

The Fe3O4 magnetic nanoparticles were prepared by precipitating ferrous ion (Fe2+) and ferric ion (Fe3+) in alkaline solution. The Fe3O4 magnetic nanoparticles were modified by tannic acid. After functionalization process, two methods were used to immobilize Lipase on Fe3O4 magnetic nanoparticles. In the first method, novel tannic acid magnetic cross-linked enzyme aggregates of lipase (TA-MNPs-CLEAs) were synthesized by cross-linking of lipase aggregates and starch as co-feeder with Fe3O4 magnetic nanoparticles improved by tannic acid (TA-MNPs). In the second method, the lipase was successfully immobilized on the surface of TA-MNPs. The properties of Fe3O4 and its modified forms were examined by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), scanning electron microscopy (SEM) and zeta potential measurements. Novel TA-MNPs-lipase and TA-MNPs-CLEAs-starch-lipase were enhanced and provided an effective method to improve the activity and stability of lipase for biodiesel production. Using 1% TA-MNPs-lipase and TA-MNPs-CLEAs-starch (w/w of oil) conversions around 67.87, and 85.88%, respectively, were obtained at 40 °C after 2 h of reaction. Furthermore, the immobilized enzyme was easily recovered from the reaction mixture and reused. The obtained results suggest that TA-MNPs-lipase and TA-MNPs-CLEAs-starch-lipase can become a powerful biocatalyst for biodiesel production.


Assuntos
Lipase/química , Nanopartículas de Magnetita/química , Amido/química , Biocombustíveis , Candida/enzimologia , Estabilidade Enzimática , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Concentração de Íons de Hidrogênio , Lipase/metabolismo , Estrutura Secundária de Proteína , Taninos/química , Temperatura
16.
Biosens Bioelectron ; 119: 34-41, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30098464

RESUMO

In this study, a photoelectrochemical (PEC) biosensor was constructed by depositing supercapacitor carbon nanotubes (CNT) and Co3O4 onto the anatase TiO2 coated ITO electrodes. Herein, supercapacitor Co3O4 was employed as a semiconductor with a band gap of ~2.07 eV, and the supercapacitor behavior of the PEC system was improved by introducing CNT into the electrode material. Furthermore, a self-empowering glucose biosensor operating at 0 V was constructed for the first time. Also, upon the formation of p-n junction, Co3O4 was rendered electron accepting material, unlike its usual use in photocatalytic systems. Co3O4-CNT-anatase TiO2 semiconductor hybrid was used to reduce recombination of exited electrons, and increasing the visible light absorption. Prior to enzyme immobilization, CNT containing electrode material was modified with 1-pyrene boronic acid via π-π interactions. The enzyme immobilization was carried out through covalent esterification between the boronic acid moiety and the carbohydrate part of GOx. Enzyme immobilization way enabled the close contact between FAD and electrode material, and the electron donor FADH2 forming after the enzymatic reaction can give electrons to the photogenerated holes of Co3O4 through CNT along with H2O2 by enhancing the photocurrent. The obtained PEC biosensor demonstrated acceptable reproducibility and decent stability with a linear measurement range of 0-4 mM, a sensitivity of 0.3 µA mM-1 cm-2, and lower detection limit of 0.16 µM. Thus, a self-powered biosensor was constructed by combining the PEC, and supercapacitor behavior of Co3O4 for the first time, and the utilization of the present PEC material can be extended to the other analytes detection through photoelectrochemistry. The supercapacitor materials led to the high current at direct electron transfer potential range, and this phenomenon implies that the PEC electrode can also be used in biofuel cells to obtain high power.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Cobalto/química , Glucose/análise , Nanotubos de Carbono/química , Óxidos/química , Titânio/química , Eletroquímica , Peróxido de Hidrogênio , Limite de Detecção , Fotoquímica , Reprodutibilidade dos Testes
17.
Int J Biol Macromol ; 118(Pt B): 2040-2050, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-30009910

RESUMO

The cross-linked enzyme aggregates (CLEAs) involves formation of a number of covalent bonds between enzyme and the matrix using glutaraldehyde. In general, amino groups of lysine, sulfhydryl groups of cysteine, phenolic OH groups of tyrosine, or imidazol group of histidine are used for enzyme binding under mild conditions. The main advantage of this method is its simplicity, economic advantages in the industrial bio catalysis. The Fe3O4 magnetic nanoparticles were synthesized by coprecipitating Fe2+and Fe3+in alkaline solution. Tannic acid was used to functionalize the Fe3O4 magnetic nanoparticles. After functionalization process, tannic acid magnetic cross-linked enzyme aggregates of enzyme (TA-MNPs-CLEAs) were prepared by cross-linking of enzyme aggregates with different saccharides as additive. The present result reported high stability, simplicity, low cost and recyclability of a saccharide-TA-MNPs-CLEAs-enzyme make it efficient as a highly active biocatalyst in biotechnological applications. The obtained results suggest that disaccharides (maltose, sucrose and lactose) and polysaccharide such as starch are eco-friendly additives to TA-MNPs-lipase and TA-MNPs-CLEAs-peroxidase and can become a powerful biocatalyst in industry applications.


Assuntos
Quitina/química , Reagentes de Ligações Cruzadas/química , Dissacarídeos/química , Lipase/metabolismo , Magnetismo , Peroxidases/metabolismo , Estabilidade Enzimática , Glutaral/química , Concentração de Íons de Hidrogênio , Nanopartículas de Magnetita/química , Nanopartículas de Magnetita/ultraestrutura , Estrutura Secundária de Proteína , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , Taninos/química , Temperatura , Difração de Raios X
18.
Int J Biol Macromol ; 118(Pt A): 610-616, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-29959006

RESUMO

BACKGROUND: It is assumed that genetic factors play crucial role in nephrolithiasis. The present study was conducted to explore the role of Human Transcription Factor-7 like-2 (TCF7L2) ß-defensin (DEFB1) and CD14 gene polymorphism in development and progression of nephrolithiasis. METHODS: The genotypes of TCF7L2, DEFB1 and CD14 polymorphism were determined in 240 nephrolithiasis patients and 240 healthy controls by restriction digestion method of PCR. The levels of serum TCF7L2, DEFB1, CD14, uric acid and other biochemical parameters were measured both in nephrolithiasis patients and healthy control. RESULTS: The patients and control groups showed 30% and 50% 1654 AA DEFB1 genotype respectively. The Allele frequency in case of patient's group was 63.67% while in control group it was 36.33%. The mean serum DEFB1 levels of the patients and control groups attained were 115.66 and 239.43 pg/mL respectively. The allele frequency of TCF7L2 in patients and controls were 44.17% and 70.0% for C-allele, 55.83% and 30.00% for T-allele respectively. The mean of serum TCF7L2 levels were significantly decreased in patients compared to control group. CONCLUSIONS: The present findings are first of its class that validates a considerable connection of DEFB1 and TCF7L2 gene polymorphisms with nephrolithiasis and could probably act as indicators to estimate the risk associated to nephrolithiasis.


Assuntos
Receptores de Lipopolissacarídeos/genética , Nefrolitíase/genética , Polimorfismo de Nucleotídeo Único , Proteína 2 Semelhante ao Fator 7 de Transcrição/genética , beta-Defensinas/genética , Feminino , Frequência do Gene , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade
19.
Int J Biol Macromol ; 117: 947-958, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29807075

RESUMO

Protease and lipase were purified from sunflower seeds by frequent purification steps with molecular weights of 72.90 kDa and 27.50 kDa, respectively. The purified lipase and protease were immobilized on various carriers by different methods of immobilization including physical adsorption, ionic binding and covalent binding. The enzymes prepared by covalent binding on a new support materials were made via the combination of chitin and starch had the highest activates. The immobilization was carried out in a simpler way compared with the other immobilization methods which require various chemicals and complicated procedures which is difficult and expensive. The influence of reusability, pH, thermal and storage stability of immobilizing enzymes compared to the free enzyme were studied. The immobilizing protease and lipase with chitin and chitin + starch were used to catalyze reactions through enhanced washing process. After adding immobilizing enzymes with chitin and chitin starch, the stain removal percentage of detergents was enhanced by 78% and 84%, respectively. We approve that these novel immobilizing protease and lipase with chitin + starch present a new approach to the synthesis of multi enzyme biocatalysts from cheap and friendly environmental sources.


Assuntos
Quitina/química , Enzimas Imobilizadas/química , Lipase/química , Peptídeo Hidrolases/química , Amido/química , Adsorção , Biocatálise , Estabilidade Enzimática , Enzimas Imobilizadas/metabolismo , Helianthus/enzimologia , Concentração de Íons de Hidrogênio , Cinética , Lipase/metabolismo , Peptídeo Hidrolases/metabolismo , Propriedades de Superfície , Temperatura
20.
Int J Biol Macromol ; 109: 720-731, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29242127

RESUMO

The non-toxic CuFe2O4 magnetic nanoparticles have been solvothermally synthesized, characterized and used as an efficient magnetic precursor for papain immobilization and then investigated antibacterial properties of them. For increasing the antibacterial activity, the silver nanoparticles were doped on CuFe2O4 magnetic nanoparticles. All prepared samples exhibited stronger antibacterial properties against Gram-positive bacteria (Staphyloccocus aureus) than Gram-negative bacteria (Escherichia coli). However, it was determined that the Ag/CuFe2O4 had a more vigorous antibacterial property against the Staphyloccocus aureus bacteria by calculating the inhibition diameter of 25 ±â€¯0.1 mm in the synthesized samples. Also, the antibacterial activity increased by immobilization of papain.


Assuntos
Cobre/química , Enzimas Imobilizadas , Compostos Férricos/química , Nanopartículas de Magnetita/química , Papaína/farmacologia , Prata/química , Taninos/química , Antibacterianos/química , Antibacterianos/farmacologia , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Ativação Enzimática , Concentração de Íons de Hidrogênio , Cinética , Nanopartículas de Magnetita/ultraestrutura , Papaína/química , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Temperatura , Termogravimetria , Difração de Raios X
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