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1.
Biotechnol J ; : e2100298, 2021 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-34743417

RESUMO

BACKGROUND: Biopolymers are promising candidates that can be fabricated into hydrophilic matrices and used for many applications due to their distinctive properties such as non-toxic, biodegradable, biocompatibility, and low cost. A promising composite of chitosan and carrageenan with self-crosslinking has been prepared. METHODS AND RESULTS: In this study, a rigorous approach for an inexpensive and non-toxic combination of different amounts of clove oil with two polyelectrolytes including chitosan and carrageenan in the form of beads have been prepared. The structure and the surface morphology of the beads were investigated using FTIR, XRD, and SEM. Moreover, antimicrobial, antiviral activity, and molecular docking were evaluated. Antibacterial results revealed that chitosan/carrageenan@clove oil beads have antimicrobial activity as well as chitosan/carrageenan without clove oil against Escherichia colia ATCC25922, Pseudomonas aeruginosa aATCC27853, Staphylococcus aureus ATCC25923, Bacillus subtilisaATCC6051 and Candida albicanssATCC90028. Furthermore, maximum non-toxic concentration (MNTC) of chitosan/carrageenan@clove oil beads was (31.25 µg/mL) which exhibited promising antiviral activity against Herpes simplex virus-1 (HSV-1), and was significantly higher than chitosan/carrageenan without clove oil, where antiviral activity was 82.94 and 57.64% respectively. Eventually, docking study and computational calculation have been used to show the reactivity of the molecules. CONCLUSIONS: The developed chitosan/carrageenan@clove oil beads have shown promising properties to be used as carriers of drug delivery, tissue engineering, and regenerative medicine. This article is protected by copyright. All rights reserved.

2.
Colloids Surf B Biointerfaces ; 209(Pt 1): 112172, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34715596

RESUMO

In this work, biocompatible, antimicrobial, and antiviral nanocomposites were prepared through two steps. In the first step, periodate oxidation of cellulose was performed to get dialdehyde cellulose (DAC). The second step included the reaction of DAC with sulfur-containing amino acids included Cysteine (Cys) and Methionine (Meth) in the presence of graphene oxide (GO). The prepared nanocomposites were characterized via FT-IR, SEM, TEM, and TGA. Antimicrobial and antiviral activities for all designed nanocomposites besides DAC were carried out. Both DAC/GO/Cys and DAC/GO/Meth exhibited a promising antimicrobial activity against Gram-negative (E. coli and P. aeruginosa), Gram-positive (B. subtilis and S. aureus), and unicellular fungi (C. Albicans and C. neoformans), while the DAC/GO/Cys/Meth nanocomposite was the lowest. Moreover, all designed nanocomposites have a strong antiviral activity against Herpes simplex virus 1(HSV-1) at minimum nontoxic concentration. Additionally, Computational procedures and Molecular docking showed the reactivity and stability of the molecules that have biological activity against Gram-positive, Gram-negative, and HSV-1. As well as DAC incorporation with amino acid enhanced their reactivity and their interaction.

3.
Biotechnol J ; : e2100183, 2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34499787

RESUMO

AIM: This study aims to prepare green nanocomposite (HPMC/5-FL@GO) from the most biocompatible materials, hydroxypropyl methylcellulose (HPMC) and graphene oxide (GO), to enhance the drug activity of immobilized 5- Fluorouracil (5-FU) with decreasing the side effect of long-run treatment protocols with highly efficient drug-drug activity. METHOD AND RESULTS: Different samples were characterized by ATR-FTIR spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), Thermogravimetric analysis (TGA), and dynamic light scattering (DLS) along with cytotoxicity and anticancer study. A homogenous and compatible nanocomposite structure with a homogenous drug distribution was confirmed. The results suggested that the prepared nanocomposite has a low cytotoxicity effect against normal Vero cell lines compared with 5-FU. The antitumor activities of the same nanocomposite (20.4 and 74.3 µg/ml on A549 and HepG-2) were lower than that of 5-FU (54.1and 103 µg/ml on A549 and HepG-2). CONCLUSION AND IMPLICATIONS: According to the attained results, the HPMC/5-FL@GO can be expected to be widely applied in a biomedical application such as cancer therapy with the unique biocompatible to human cells. This article is protected by copyright. All rights reserved.

4.
Int J Biol Macromol ; 167: 1091-1101, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33186652

RESUMO

According to the World Health Organization, nearly a billion people do not have incoming to pure drinking water and much of that water is contaminated with high levels of heavy elements. In this study, adsorption of lead ions has been studied by nanocomposites which prepared through acrylic acid grafting and amino-functionalized magnetized (FM-NPs) TEMPO-oxidized cellulose nanofiber (TEMPO-CNF). The amino-functionalized magnetite was acting as a crosslinked. The crystallinity of TEMPO-CNF was 75 with a 4-10 nm diameter range, while the average particle size of FM-NPs was 30 nm. The adsorption studies illustrated that the elimination efficiency of lead ions was 80% by the prepared nanocomposite that includes a minimum amount of crosslinker (1%), which demonstrated that the magnetic grafted oxidized cellulose nanofiber nanocomposite is a promising green adsorbent material to eliminate heavy metal ions and is additionally easy to get rid of due to its magnetic property. The kinetics and isotherms studied found that the sorption reaction follows a pseudo-second-order model (R2 = 0.997) and Freundlich model (R2 = 0.993), respectively, this indicated that the adsorption of lead ion occurs within the pores and via the functional groups present on the nanocomposite.


Assuntos
Celulose Oxidada/química , Óxidos N-Cíclicos/química , Íons/química , Chumbo/química , Nanofibras/química , Acrilatos/química , Adsorção , Técnicas de Química Sintética , Reagentes para Ligações Cruzadas/química , Cinética , Nanopartículas de Magnetita/química , Nanopartículas de Magnetita/ultraestrutura , Metais Pesados , Purificação da Água
5.
Biosensors (Basel) ; 10(6)2020 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-32560377

RESUMO

Cellulose has attracted much interest, particularly in medical applications such as advanced biosensing devices. Cellulose could provide biosensors with enhanced biocompatibility, biodegradability and non-toxicity, which could be useful for biosensors. Thus, they play a significant role in environmental monitoring, medical diagnostic tools, forensic science, and foodstuff processing safety applications. This review summarizes the recent developments in cellulose-based biosensors targeting the molecular design principles toward medical detection purposes. The recognition/detection mechanisms of cellulose-based biosensors demonstrate two major classes of measurable signal generation, including optical and electrochemical cellulosic biosensors. As a result of their simplicity, high sensitivity, and low cost, cellulose-based optical biosensors are particularly of great interest for including label-free and label-driven (fluorescent and colorimetric) biosensors. There have been numerous types of cellulose substrates employed in biosensors, including several cellulose derivatives, nano-cellulose, bacterial cellulose, paper, gauzes, and hydrogels. These kinds of cellulose-based biosensors were discussed according to their preparation procedures and detection principle. Cellulose and its derivatives with their distinctive chemical structure have demonstrated to be versatile materials, affording a high-quality platform for accomplishing the immobilization process of biologically active molecules into biosensors. Cellulose-based biosensors exhibit a variety of desirable characteristics, such as sensitivity, accuracy, convenience, quick response, and low-cost. For instance, cellulose paper-based biosensors are characterized as being low-cost and easy to operate, while nano-cellulose biosensors are characterized as having a good dispersion, high absorbance capacity, and large surface area. Cellulose and its derivatives have been promising materials in biosensors which could be employed to monitor various bio-molecules, such as urea, glucose, cell, amino acid, protein, lactate, hydroquinone, gene, and cholesterol. The future interest will focus on the design and construction of multifunctional, miniaturized, low-cost, environmentally friendly, and integrated biosensors. Thus, the production of cellulose-based biosensors is very important.


Assuntos
Técnicas Biossensoriais , Celulose/química , Técnicas e Procedimentos Diagnósticos/instrumentação , Técnicas Eletroquímicas , Humanos , Imagem Óptica
6.
Carbohydr Polym ; 242: 116402, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32564844

RESUMO

Adsorption is the most efficient technique for the removal of metal ions and organic dyes from water. This stimulates demand for the preparation of eco-friendly adsorbents. In this study, magnetic hydrogels based on a crosslinked carboxymethyl cellulose grafted acrylamide (CMC-g-AM) embedded with porous carbon (PC) and citric acid-modified magnetite were prepared. PC was synthesized via single-step oxidation of bagasse under muffled atmosphere condition. The magnetite (Fe3O4) nanoparticles were synthesized using the co-precipitation method (Fe2+/Fe3+) and citric acid modification (CFe). Functionality and parameters of adsorbent were characterized by infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray. The magnetic hydrogels have a highly effective performance for Pb-ions and methylene blue dye (MB) removal from water due to the unique role of crosslinked CMC matrix in supporting synergy between embedded PC and CFe. Adsorption testing using time intervals (5-120 min) and Pb-ions and MB concentrations (5-500 mg/L) indicate that CMC-g-AM containing equal content of PC and CFe has substantially higher removal efficiency; 70.8 and 96.1 % against 47.8 and 30.2 % (without PC and CFe) for Pb-ions and MB adsorption respectively for CMC-g-AM. The equilibrium time and the maximum sorption capacity (qm) from the adsorption studies were found to be 60 and 30 min and 294.1 and 222.2 mg/g for Pb-ions and MB respectively. The kinetics and isotherms were studied to highlight the adsorption rate and mechanism of the adsorption process.

7.
Carbohydr Polym ; 236: 116032, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32172848

RESUMO

Cyanoethyl cellulose (CEC)/ magnetite (Fe3O4) flexible composite film with enhanced dielectric and magnetic properties was successfully prepared. CEC has been synthesized from micro crystalline cellulose (MCC). The effects of magnetite mass fraction on the morphology, microstructure, thermal stability, and antimicrobial activity of the as-prepared composite films were investigated. The Vibrating sample magnetometer (VSM) and broadband dielectric spectrometer was also employed to study the magnetic and dielectric properties, respectively. In addition to study the computational calculation of MCC, and CEC by DFT/ B3LYP/6-31G (d) basis sets. The results showed that, the sample that is magnetite free has a diamagnetic response to the applied magnetic field, however the other samples that is loaded with magnetite show super-paramagnetic behavior indicating that the particles' sizes of the magnetite mostly below 20 nm. Also, antimicrobial activities of composite films against (G + ve), (G-ve), were investigated.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Celulose/análogos & derivados , Celulose/farmacologia , Óxido Ferroso-Férrico/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Antifúngicos/síntese química , Antifúngicos/química , Aspergillus niger/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Celulose/síntese química , Teoria da Densidade Funcional , Condutividade Elétrica , Escherichia coli/efeitos dos fármacos , Óxido Ferroso-Férrico/química , Fenômenos Magnéticos , Modelos Químicos , Porosidade , Staphylococcus aureus/efeitos dos fármacos
9.
Luminescence ; 35(4): 478-485, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31854500

RESUMO

A facile approach for possible industrial production of long-persistent phosphorescence, continuing to emitting light for a long time period, smart cobbles were developed toward photoluminescent hard surfaces. The inorganic strontium aluminium oxide pigment doped with rare earth elements was added to a synthetic organic epoxy in the presence of polyamine as a hardener to make a phosphor-loaded viscous fluid that can then be hardened in a few minutes. The transparency of the solid cobbles can be accomplished easily using homogeneous dispersion of the phosphor in the epoxy resin fluid before the addition of a hardener to avoid pigment aggregation. This pigment-epoxy formula can be easily applied industrially onto flagstones surfaces under ambient conditions. The photoluminescent cobblestones demonstrated an optimum excitation wavelength at 366 nm and an emission band at 521 nm with a long-persistent phosphorescence cobble surface. The development of a translucent white colour under normal daylight, bright green under ultraviolet (UV) irradiation, bright white colour after 30 sec in the dark, and phosphorescent green colour after 75 min in the dark was indicated using Commission Internationale de l'Eclairage (CIE) Laboratory coloration measurements. The luminescent hard composite cobble exhibited a highly durable and reversible long-persistent phosphorescence light. Photoluminescence, morphological, and hardness properties as well as the elemental composition of the prepared cobbles were explored.


Assuntos
Óxido de Alumínio/química , Resinas Epóxi/química , Európio/química , Luminescência , Estrôncio/química , Medições Luminescentes , Tamanho da Partícula , Processos Fotoquímicos , Propriedades de Superfície
10.
Talanta ; 205: 120166, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31450476

RESUMO

Collecting sweat sample for onsite testing is a sophisticated process as the analysis process must be completed in a real-time with a highly absorptive and sensitive device in order to gain a useful assessment of its content. Thus, we developed a chemical probe incorporated into microfibrillated cellulose to introduce a novel, simple, robust and flexible aerogel. This chromogenic sponge-like aerogel assay demonstrated a color change from yellow to orange, red and blue depending on the sweat biochemical changes. Novel pH sensitive tricyanofuran hydrazone probe was prepared, characterized and encapsulated in-situ within microfibrillated cellulose to follow up sweat pH changes. The solvatochromic performance in several solvents of different polarities and the reversible pH correlated color change of this tricyanofuran hydrazone probe in an acetonitrile solution was explored by UV-Vis absorption spectra. The microporous and microfibrillated sponge-like cellulose substrate was fabricated by activation of wood pulp using phosphoric acid followed by freeze-drying process. Morphological characterization, thermal stability and fiber crystallinity of the prepared aerogel were explored using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The visual color change was explored by studying the CIE LAB color space coordinates and color strength values. The cytotoxicity of the sponge-like aerogel sensor was also evaluated.


Assuntos
Celulose/química , Colorimetria/métodos , Suor/química , Linhagem Celular , Furanos/síntese química , Furanos/química , Géis , Humanos , Concentração de Íons de Hidrogênio , Nitrilas/síntese química , Nitrilas/química , Solventes/química , Temperatura , Fatores de Tempo
11.
J Fluoresc ; 29(3): 693-702, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31041695

RESUMO

A practical fluorescent test dipstick for an efficient recognition of ammonia and amines vapors was developed. The prepared testing strip was based on a composite of molecularly imprinted chitosan nanoparticles, supported on cellulose paper assay, with artificial fluorescent receptor sites for ammonia/amines recognition in aqueous and gaseous phases. A modified chitosan nanoparticles containing fluorescein molecules, were successfully prepared and employed on cellulose paper strip creating fluorescent cellulose (FL-Cell) to act as "turn-on" fluorescent sensor for sensing and determining ammonia and organic amine vapor. We employed chitosan nanoparticles that had fluorescein incorporated as the fluorescent probe molecule, with a readout limit achieved for aqueous ammonia as low as 280 ppm at room temperature and atmospheric pressure. The sensor responded linearly relying on the aqueous ammonia concentration in the range of 0.13-280 ppm. The chromogenic fluorescent cellulose platform response depended on the acid-base characteristic effects of the fluorescein probe. The protonated form of fluorescein molecules immobilized within the chitosan nanoparticles were in a nanoenvironment demonstrating only weak fluorescence. When binding to ammonia/amine vapor, the fluorescein active sites were deprotonated and exhibited higher "turned-on" fluorescence as a result of exposure to those alkaline species. The simple fabrication and abovementioned characteristics of such fluorescent chitosan nanoparticles are such that they should be applicable for monitoring of ammonia/amines in either aqueous or vapor states. We studied the distribution of the fluorescent chitosan onto paper sheets fabricated from bleached bagasse pulp and coated with two different thicknesses of a fluorescent nanochitosan and blank nanochitosan solutions. A thin fluorescent nanochitosan layer was created on the surface of cellulose strips using an applicator. Its distribution was assessed by scanning electron microscopic (SEM) and transmission electron microscopic (TEM) analysis as well as Fourier-transform infrared spectroscopic (FT-IR) measurements. The mechanical properties were also tested. The exploitation of this "turn-on" fluorescence sensor invented platform should be amenable to different situations where determination of ammonia/amine vapor or aqueous solution is required.

12.
Int J Biol Macromol ; 132: 351-359, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30914362

RESUMO

In this work regenerated cellulose was prepared by phosphoric acid as a primarily step in preparation of biodegradable foam. Copper nanoparticles (Cu-NPs) were embedded onto the cellulosic suspensions followed by freeze drying process. The scanning electron microscopy (SEM) revealed the presence of individual chunky regenerated cellulose fibers in the dimensions of micro that enhanced tendency to aggregate during drying. X-ray diffraction (XRD) demonstrated that, the treatment of cellulose with concentrated phosphoric acid led to defibrated cellulose with lower crystallinity index than original cellulose fibers. The study provided insights about the influence of the Cu-NPs on the structure, thermal stability and the electrical contributions of the considered cellulose-based foam. The electrical and dielectric properties were studied by means of the broadband dielectric spectroscopy. The dielectric spectra were dominated by an anomalous behavior of the permittivity as illustrated versus frequency of the investigated samples. The real part of conductivity follows the universal power law at higher frequencies. The foam loaded Cu-NPs exhibit biodegradability and highly efficient antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans.


Assuntos
Anti-Infecciosos/química , Celulose/química , Cobre/química , Nanopartículas Metálicas/química , Semicondutores , Anti-Infecciosos/farmacologia , Celulose/metabolismo , Cobre/farmacologia , Impedância Elétrica , Liofilização
13.
Carbohydr Polym ; 210: 196-203, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30732754

RESUMO

Microporous cellulose xerogel can be defined as low density biomaterial that can be employed for a variety of promising applications of different fields. The characteristics of xerogel are a consequence of their microstructure. An easy-to-use and reversible solid-state colorimetric sensor for ammonia gas was developed by embedding a bromocresol purple (BCP) pH-sensory chromophore into the environmental friendly carboxymethyl cellulose as bio-based polymer (CMC) matrix. The bromocresol purple was immobilized into cross-linked carboxymethyl cellulose (CMC-BCP) xerogel followed by freeze-drying to introduce a microporous network of regenerated cellulose host in which bromocresol purple chromophore was immobilized to function as a spectroscopic probe guest. Identification of ammonia gas occurred via proton shift from the hydroxyl group of the BCP dye to ammonia nitrogen. Both qualitative and quantitative activities were determined. The architectures of the prepared cellulose xerogel at different degree of substitutions (DS) was investigated using Fourier-transform infrared spectroscopy (FTIR) and scan electron microscopy (SEM), which displayed a high porosity and pores diameter in the range of 10-50 µm. The resultant CMC-BCP displayed high sensitivity for gaseous ammonia. Moreover, excellent reversibility and short detection time were also monitored. The vapochromic xerogel provided an instant color alteration signal from yellow to purple when exposed to ammonia gas or an ammonium hydroxide aqueous environment as monitored by the absorption maxima, color coordinates and color strength. The visual color change of CMC-BCP xerogel was observed to alter in the order from yellow, orange, red to purple in proportional with raising the ammonia concentration in an aqueous environment. Moreover, the CMC-BCP xerogel displayed rapid response time, concentration detection limit as low as 9.0 × 10-2 ppb for ammonia in aqueous media, and very good reversibility.

14.
Carbohydr Polym ; 200: 154-161, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30177153

RESUMO

A simple formulation of an organic-inorganic composite for spray-coating was adopted toward photoluminescent paper sheets. The coating composite layer was composed of a synthetic organic adhesive binder mixed with an inorganic lanthanide-doped strontium aluminate pigment. Such pigment-binder formula was applied effectively onto paper sheets via spray-coating followed by thermal fixation. The applied transparent photoluminescent coated layer exhibited optimal excitation wavelength at 365 nm and emission band at 517 nm resulting in phosphorescence of the paper surface with a substantial development of green-yellow, bright white, turquoise, and off-white colors as indicated by CIE Lab color coordinates under ultraviolet irradiation. The mechanical, decay and lifetime properties of the composite photoluminescent coated layer were described. The standard techniques of morphological properties and elemental analysis were explored by scanning electron microscope (SEM), wavelength dispersive X-ray fluorescence (WDXRF), and energy dispersive X-ray spectroscopic analysis (EDX). The spray-coated paper sheets demonstrated good fastness to light and reversible phosphorescence without fatigue.

15.
Carbohydr Polym ; 199: 193-204, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30143120

RESUMO

In the present study, tosylcellulose (TC) was used as a key intermediate for the selective coupling with 3-aminopropyltrimethoxysilane (APTMS) affording amino-propylsilane-grafted tosylcellulose (TC-Si). Solid state 13C NMR and FT-IR analyses confirmed the coupling and self-condensation of APTMS along TC. The changes in the surface morphology of the functionalized cellulose were identified by SEM imaging. The thermal stability of TC-Si was significantly improved as compared to MCC and TC. A new organic/inorganic hybrid cellulosic material was fabricated by embedding TiO2 nanoparticles into TC-Si network. The new cellulose polymers were investigated for their ability to promote the proliferation of human skin fibroblast (BJ1). The cell cytotoxicity assay showed that both TC and TC-Si possessed moderate toxicity to BJ1 cells by 17% and 23.8%, respectively at 20 µM. Meanwhile, TC-Si/TiO2 hybrid enhanced the proliferation of BJ1 by 42%. Additionally TC-Si/TiO2 hybrid demonstrated promising antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans.


Assuntos
Anti-Infecciosos/farmacologia , Proliferação de Células/efeitos dos fármacos , Celulose/análogos & derivados , Fibroblastos/efeitos dos fármacos , Propilaminas/farmacologia , Silanos/farmacologia , Titânio/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Antibacterianos/toxicidade , Anti-Infecciosos/síntese química , Anti-Infecciosos/química , Anti-Infecciosos/toxicidade , Antifúngicos/síntese química , Antifúngicos/química , Antifúngicos/farmacologia , Antifúngicos/toxicidade , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/toxicidade , Candida albicans/efeitos dos fármacos , Linhagem Celular , Celulose/síntese química , Celulose/farmacologia , Celulose/toxicidade , Humanos , Nanopartículas/química , Nanopartículas/toxicidade , Porosidade , Propilaminas/química , Propilaminas/toxicidade , Pseudomonas aeruginosa/efeitos dos fármacos , Silanos/química , Silanos/toxicidade , Staphylococcus aureus/efeitos dos fármacos , Tecidos Suporte/química , Titânio/química , Titânio/toxicidade
16.
Int J Biol Macromol ; 119: 207-214, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30036619

RESUMO

2,3,6­Tricarboxy cellulose nanofiber (TPC-CNFs) was prepared by 2,2,6,6-tetramethylpiperidine­1­oxyl (TEMPO) oxidation of dissolving cellulose pulp (selective at C-6) followed by periodate-chlorite oxidation (selective on C-2 and C-3). Characterization of the prepared samples were carried out using, atomic force microscope (AFM), carboxylate content determination, FTIR spectroscopy, X-ray diffraction and light transmittance spectra. Also, the mechanical properties of TEMPO-oxidized of cellulose nanofiber (T-CNFs) and TPC-CNFs with and without polyamide-amine-epichlorohydrin crosslinker (PAE) films were determined which the tensile strength were 8.19, 12.43 and 20.5 MPa and elastic moduli of 1814, 1097 and 1150 MPa respectively. Tricaboxy cellulose nanofiber was developed as a novel adsorbent of heavy metal ions. Removal of heavy metals such as Cu2+, Ca2+ and Pb2+ from aqueous solution was carried out and the adsorption efficiencies were analyzed. On the other hand, the effect of the addition of the crosslinking agent to CNFs and the carboxylate contents of CNFs were investigated.


Assuntos
Íons , Metais Pesados/química , Nanofibras/química , Soluções/química , Adsorção , Óxidos N-Cíclicos/química , Oxirredução , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/química , Difração de Raios X
17.
Int J Biol Macromol ; 117: 179-188, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29807082

RESUMO

The cellulose-based antimicrobial hydrogel was prepared from seed and husk cellulosic fibers of olive industry residues by load silver nanoparticles (AgNPs) onto grafted acrylamide monomer (Am) cellulosic fibers. The grafting approach was the free radical mechanism by utilizing ceric ammonium nitrate (CAN) as initiator in aqueous medium and N,N methylene bisacrylamide (MBAm) as a cross linker. The effect of different grafting conditions on the properties of produced hydrogels has been studied by determining the grafting parameters, i.e. concentration of Am, MBAm, grafting time and temperature to optimize grafting yield (G %), grafting efficiency (GE %), and swelling %. Characterizations of the obtained hydrogels were performed through monitoring swelling behavior, FTIR spectroscopy, SEM, and EDX. AgNPs were grown into the prepared hydrogel. Hydrogel/AgNPs were characterized by FT-IR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The hydrogel loaded AgNPs exhibit high efficient antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Celulose/química , Celulose/farmacologia , Hidrogéis/química , Resíduos Industriais , Azeite de Oliva/química , Candida albicans/efeitos dos fármacos , Cinética , Nanopartículas Metálicas/química , Pseudomonas aeruginosa/efeitos dos fármacos , Prata/química , Staphylococcus aureus/efeitos dos fármacos , Temperatura
18.
Int J Biol Macromol ; 114: 363-372, 2018 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-29588205

RESUMO

The development of new biocompatible, biodegradable functionalized biopolymers that can serve as scaffold for tissue regeneration or work as carriers for different bioactive molecules such as drugs, proteins, and enzymes remains a continuous challenge that need to be extensively explored. For this purpose, three water-soluble cellulose derivatives; namely 4(celluloseamino) butyric acid (CABA) 2(celluloseamino) succinic acid (CASA), and 3(celluloseamino) propane sulfonic acids (CAPSA) were synthesized from microcrystalline cellulose (MCC) via esterification with tosyl chloride that was followed by nucleophilic substitution by the proper aminoalkyl acid derivative. The products were characterized by elemental analyses, FTIR, 13C NMR spectroscopy. The thermal stability, surface morphology, and the elemental composition of the new ampholytic biopolymers were also studied by TGA, EDX-SEM. The new ampholytic cellulose derivatives were evaluated for their in vitro cytotoxicity on normal human retina cell line (RPE1) by MTT assay.


Assuntos
Celulose , Teste de Materiais , Retina/metabolismo , Linhagem Celular , Celulose/síntese química , Celulose/química , Celulose/farmacologia , Esterificação , Humanos , Retina/citologia
19.
Carbohydr Polym ; 168: 182-190, 2017 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-28457439

RESUMO

Cellulose/polypyrrole and cellulose/polypyrrole-TiO2 composites were prepared via in situ oxidative chemical polymerization of pyrrole using FeCl3 as oxidant. The concentration effect of pyrrole on the structure and properties of prepared matrix has been investigated. Furthermore, the structure of the prepared materials was characterized using Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), X-ray Diffraction (XRD), and Thermal gravimetrical analysis (TGA). The results exhibited that the addition of cellulose and TiO2 increase the thermal stability of the polypyrrole system. Moreover, dielectric properties of the obtained composites were studied over frequency range from 42Hz to 5MHz. The electrical measurements including dielectric constant, ε'(ω), dielectric loss, ε''(ω), loss tangent, tan δ and ac conductivity, σac were carried.

20.
Talanta ; 170: 137-145, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28501149

RESUMO

A simple, portable and highly sensitive naked-eye test strip is successfully prepared for optical detection of gaseous and aqueous alkaline analytes. Novel pH-sensory tricyanofuran-hydrazone (TCFH) disperse colorant containing a hydrazone recognition functional moiety is successfully synthesized via azo-coupling reaction between active methyl-containing tricyanofuran (TCF) heterocycle and diazonium salt of 4-aminobenzaldehyde followed by Knoevenagel condensation with malononitrile. UV-vis absorption spectra display solvatochromism and reversible color changes of the TCFH solution in dimethyl sulfoxide in response to pH variations. We investigate the preparation of hydrophobic cellulose/polyethylene terephthalate composites characterized by their high affinity for disperse dyes. Composite films made from CA, Cell/CA, PET/CA, and Cell/PET-CA are produced via solvent-casting procedure using 10-30% modified cellulose or modified polyethylene terephthalate. The mechanical properties and morphologies of these composite films are investigated. The prepared pH-sensory hydrazone-based disperse dye is then applied to dye the produced cellulose-based composite films employing the high temperature pressure dyeing procedure. The produced halochromic PET-CA-TCFH test strip provide an instant visible signal from orange to purple upon exposure to alkaline conditions as proved by the coloration measurements. The sensor strip exhibits high sensitivity and quick detection toward ammonia in both of aqueous and vapor phases by naked-eye observations at room temperature and atmospheric pressure.


Assuntos
Celulose/química , Compostos de Anilina/química , Benzaldeídos/química , Cor , Corantes/química , Furanos/química , Hidrazonas/química , Concentração de Íons de Hidrogênio , Fenômenos Mecânicos , Nitrilas/química , Fitas Reagentes/química , Volatilização , Água/química
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