Temat: chitosan - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Use of Chitosan Adsorbents for Dye Removal in the Air-Lift Reactor
Autorzy:: Filipkowska, Urszula
Jóźwiak, Tomasz
Filipkowska, Magdalena
Tematy:: chitosan
chitosan beads
modified sawdust immobilised in chitosan
dye; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Powiązania:: https://bibliotekanauki.pl/articles/57552157.pdf Link otwiera się w nowym oknie
Opis:: Adsorption tests in the air-lift reactor were carried out for six dyes – four anionic (RR11, RB5, RB8, and RR18) and two cationic (BV10 and BG 4) – as well as three adsorbents – chitosan flakes, chitosan in the form of beads, and modified sawdust immobilised in chitosan (adsorbent 3). The dye concentration in the inflow to the reactor in all the conducted test series was 10 mg/dm3; the amount of adsorbent was also constant at 10 g dry matter (d.m./dm3, and the flow rate was 0.1 V/h. For all tested dyes, the obtained maximum adsorption capacity was high and ranged from 3802 to 2203 mg/g d.m. for chitosan flakes, from 3312 to 2076 mg/g d.m. for chitosan beads, and from 2734 to 2148 mg/g d.m. for modified sawdust immobilised in chitosan. The immobilisation of sawdust on chitosan resulted in effective adsorption of both anionic and cationic dyes.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: The formation of hydrogels based on chitosan and its water-soluble derivatives
Autorzy:: Il’ina, Alla V.
Shagdarova, Balzhima Ts.
Lunkov, Alexey P.
Varlamov, Valery P.
Tematy:: chitosan
crosslinking agent
gelation
hydrogels
quaternized chitosan
succinyl chitosan; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Powiązania:: https://bibliotekanauki.pl/articles/1034059.pdf Link otwiera się w nowym oknie
Opis:: This review considers articles on the formation of hydrogels based on chitosan as well as succinylated and quaternized chitosan derivatives. They are synthesized using low toxicity reagents, under ordinary conditions (low production costs). Chitosan derivatives are soluble in an extended range of pH values and characterized by mucoadhesiveness, bioavailability and biodegradability, which extends the potential of their medical applications. One of the most important properties of chitosan and its derivatives is the ability to form hydrogels. Depending on the nature of the bonds that occur during formation, hydrogels are divided into chemically or physically crosslinked, or a mixture of the two. Chemically crosslinked gels have covalent bonds, while physically crosslinked gels are formed by noncovalent interactions, for example, ionic. Mixed hydrogels have both types of crosslinking.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Advanced cellulosic materials
Autorzy:: Brzoza-Malczewska, Kinga
Kucharska, Magdalena
Wiśniewska-Wrona, Maria
Guzińska, Krystyna
Jóźwicka, Jolanta
Bacciarelli-Ulacha, Anna
Tematy:: cellulosicproducts
chitosan
complex chitosan/alginate
nanoparticles; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Powiązania:: https://bibliotekanauki.pl/articles/1034809.pdf Link otwiera się w nowym oknie
Opis:: Aim of the work was to prepare a method of producing chitosan and chitosan-alginate nanoparticles designed for the modification of textile cellulosic products in hygiene and medical application. Spectrophotometry was used in the estimation of the prepared nanoparticles; analyzed, too, was the particle size and antibacterial and antifungal activity.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Modyfikacja chitozanu : krótki przegląd
Modification of chitosan : a concise overview
Autorzy:: Ostrowska-Czubenko, J.
Pieróg, M.
Gierszewska, M.
Tematy:: chitozan
modyfikacja chitozanu
pochodne chitozanu
sieciowanie
chitosan
chitosan modification
chitosan derivatives
crosslinking; Pokaż więcej
Wydawca:: Polskie Towarzystwo Chemiczne
Powiązania:: https://bibliotekanauki.pl/articles/172373.pdf Link otwiera się w nowym oknie
Opis:: Chitosan is the most important derivative of chitin, a polysaccharide found in the exoskeleton of shellfish like shrimp and crab. It is a product of deacetylation of chitin under alkaline conditions or enzymatic hydrolysis in the presence of chitin deacetylase. Both chitin and chitosan are linear polysaccharides and are chemically defined as copolymers consisting of varying amounts of β-(1→4)- linked 2-acetamido-2-deoxy β-D-glucopyranose (GlcNAc) and 2-amino-2-deoxy- β-D-glucopyranose (GlcN). The difference between chitin and chitosan lies in the content of GlcNAc and GlcN units. Chitin samples contain a high content of Glc- NAc units. Due to excellent properties of chitosan, such as biocompatibility, biodegradability, hydrophilicity, non-toxicity, cationicity, ease of modification, film forming ability, affinity to metals, protein and dyes, etc., this polymer has found applications in medicine and pharmacy, as food additive, antimicrobial agent, in paper and textile industry, in environmental remediation and other industrial areas. The presence of functional groups, reactive amino and hydroxyl groups, in chitosan backbone makes it suitable candidate for chemical modification. Chemical modification of chitosan to generate new polymers with useful physicochemical properties and distinctive biological functions is of key interest because it would not change the fundamental skeleton of the polymer. In this article the main three methods of chitosan modification: substitution reactions, reactions leading to the chain elongation and/or molecular weight increasing and methods of depolymerization are shortly characterized. Moreover, the selected methods of chitosan modification, i.e. quaternization, alkylation, acylation, carboxyalkylation, phosphorylation, sulfation, graft copolymerisation, crosslinking and depolymerization are discussed in more detail. A special attention is drawn to chitosan crosslinking with low and high molecular compounds. Chitosan modification by covalent and ionic crosslinking allows to obtain polymer materials with improved mechanical and chemical resistance and suitable for example for chitosan hydrogel membranes formation. Keywords: chitosan, chitosan modification, chitosan derivatives, crosslinking
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Synthesis of chitosan and carboxymethyl chitosan hydrogels by electron beam irradiation
Autorzy:: Czechowska-Biskup, Renata
Wach, Radosław
Stojek, Piotr
Kamińska, Martyna
Rosiak, Janusz M.
Ulański, Piotr
Tematy:: PEGDA
carboxymethyl chitosan
chitosan
hydrogel
radiation crosslinking; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Powiązania:: https://bibliotekanauki.pl/articles/1034681.pdf Link otwiera się w nowym oknie
Opis:: Solutions of chitosan (CS) and carboxymethyl chitosan (CMCS) were subjected to irradiation by electron beam in presence of a crosslinking agent (poly(ethylene glycol) diacrylate - PEGDA) in order to produce carboxymethyl chitosan- and chitosan-based hydrogels. PEGDA macromonomer itself undergoes simultaneous polymerization and crosslinking either in neutral water or in acidic medium. Acidic solutions of chitosan of 0.5, 1 and 2% can be effectively crosslinked with PEGDA to form a gel. Although CMCS undergoes radiation-initiated crosslinking only at high concentration in water (over 10%), the presence of PEGDA in solution facilitated hydrogel formation even at lower concentration of CMCS. Formation of CS and CMCS hydrogels required irradiation doses lower than those needed for sterilization, i.e. 25 kGy, in some cases even as low as 200 Gy. Sol-gel analysis revealed relatively high gel fraction of obtained hydrogels, up to 80%, and good swelling ability. Both parameters can be easily controlled by composition of the initial solution and irradiation dose. Possible mechanisms of crosslinking reactions were proposed, involving addition of the polysaccharide macroradicals to a terminal double bond of PEGDA.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Formation and characterization of succinoyl chitosan particles loaded with warnerin
Autorzy:: Shagdarova, Balzhima Ts
Ilyina, Alla V.
Lopatin, Sergey A.
Korobov, Vladimir P.
Lemkina, Larisa M.
Varlamov, Valery P.
Tematy:: chitosan nanoparticles
coacervation method
succinoyl chitosan
warnerin; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Powiązania:: https://bibliotekanauki.pl/articles/1034836.pdf Link otwiera się w nowym oknie
Opis:: This study aims to obtain nanoparticles based on succinoyl chitosan loaded with Warnerin (War-SCNPs), low molecular weight cationic peptide. The nanoparticles of succinoyl chitosan (SCNPs) were prepared by salt coacervation method, and Warnerin loading efficiency on SCNPs was reached 75% in the optimum conditions, particularly, ration (SCNPs : peptide) was equal to (1.75 : 1, μg / ml ). Formed War-SCNPs were stable, had a weak electric charge from (-4.4) to (-14,6) mV. Determining of SCNPs size showed that a main fraction of SCNPs had the size of 160 nm, and after the peptide sorption War-SCNPs size increased up to 330 nm. The experimental data of this study will likely impact War-SCNPs use as therapeutic delivery systems of the peptide to be administered parenteral.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Novel synthesis of PEGylated chitosan. Part II: Research
Nowa synteza PEGylowanego chitozanu. Część II: Badania
Autorzy:: Wyrębska, Łucja
Masłowska-Lipowicz, Iwona
Słubik, Anna
Tematy:: synthesis
chitosan
poly(ethylene glycol)
PEGylated chitosan
synteza
chitozan
poli(glikol etylenowy)
PEGylowany chitosan; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Przemysłu Skórzanego
Powiązania:: https://bibliotekanauki.pl/articles/2175896.pdf Link otwiera się w nowym oknie
Opis:: This article is a continuation of the article: Synthesis and evaluation of the possibility of using some chitosan derivatives in the leather industry. Part I: Literature Review [1]. Part II describes the synthesis of methoxy poly (ethylene glycol) chitosan (mPEGylated chitosan). Methoxy poly(ethylene glycol) with two different molecular weights was used. The effective grafting of poly(ethylene glycol) (PEG) with chitosan was preceded by the activation of the hydroxyl group in the PEG molecule. Benzenesulfonyl chloride was used to activate the hydroxyl group. The course of the reaction for the preparation of PEG esters and PEG-chitosan was confirmed by chromatography.
Praca jest kontynuacją artykułu: Synteza i ocena możliwości wykorzystania niektórych pochodnych chitozanu w przemyśle skórzanym. Część I: Przegląd literatury [1]. W części II opisano syntezę metoksypoli(glikolu etylenowego) chitozanu (mPEGylowanego chitozanu). Stosowano metoksypoli(glikol etylenowy) o dwóch różnych masach cząsteczkowych. Efektywne szczepienie poli(glikolu etylenowego) (PEG) chitozanem poprzedzone było aktywacją grupy hydroksylowej w cząsteczce PEG. Chlorek benzenosulfonylu zastosowano do aktywacji grupy hydroksylowej. Przebieg reakcji otrzymywania estrów PEG i PEG-chitozanu potwierdzono chromatograficznie.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Development of mucoadhesive chitosan-based drug delivery system
Autorzy:: Konovalova, Mariya
Shagdarova, Balzhima
Zubareva, Anastasia
Generalov, Alexander
Grechikhina, Maria
Svirshchevskaya, Elena
Tematy:: chitosan
drug delivery systems
hexanoylchitosan
mucoadhesion
quaternised chitosan; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Powiązania:: https://bibliotekanauki.pl/articles/1034369.pdf Link otwiera się w nowym oknie
Opis:: Chitosan is a highly versatile biopolymer characterised by low toxicity, biocompatibility, and slow but complete biodegradation in the human body, possessing multiple reactive groups. One of the most well-known properties of positively charged chitosan derivatives is their ability to bind mucous membranes. The aim of this work was the analysis of mucoadhesion of unmodified 20 kDa chitosan and its hydrophobic (HC) and hydrophobic quaternised (QHC) derivatives in vitro and ex vivo. Unmodified chitosan formed large aggregates in vitro in keratinocyte and colon cell cultures and ex vivo in murine small intestine and muscle explants. At the same time, HC and especially QHC bound cells in vitro and ex vivo in a fine dotted manner, as evidenced by confocal microscopy. Such a pattern of hydrophobic derivatives distribution provides the possibility to develop mucoadhesive drug delivery systems with increased local drug release and improved chitosan biodegradation.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Application of cross-linked chitosan for phosphate removal from aqueous solutions
Autorzy:: Filipkowska, Urszula
Jóźwiak, Tomasz
Szymczyk, Paula
Tematy:: adsorption
chitosan
cross-linked chitosan
epichlorohydrin
glutaraldehyde
phosphates; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Powiązania:: https://bibliotekanauki.pl/articles/1035181.pdf Link otwiera się w nowym oknie
Opis:: This study investigated the effectiveness of phosphate adsorption onto non-cross-linked chitosan beads [CHs], and onto chitosan beads cross-linked with glutaraldehyde [ALD-CHs] and epichlorohydrin [ECH-CHs]. The weight ratio of glutaraldehyde to chitosan was 1:2 (w/w), whereas that of epichlorohydrin to chitosan was 2:1 (w/w). The optimal pH value of the phosphate adsorption process was determined at pH 3 for cross-linked chitosan and at pH 4 for noncross- linked chitosan. The time needed to reach the equilibrium concentration reached 60 min for both adsorbents. Experimental data were described with the heterogeneous Langmuir model (double Langmuir equation). The most effective adsorbent of phosphates was shown to be chitosan cross-linked with epichlorohydrin [ECH-CHs] - for which the adsorption capacity reached 139.4 mg/g d.m.CHs. In the case of the remaining adsorbents (chitosan [CHs] and chitosan crosslinked with glutaraldehyde [ALD-CHs]) the adsorption capacity was lower and accounted for 44.38 mg/g d.m.CHs and 108.24 mg/g d.m.CHs, respectively.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Effectiveness of dye adsorption onto non-cross-linked and cross-linked chitosan beads
Autorzy:: Filipkowska, Urszula
Tematy:: adsorption
chitosan beads
cross-linked chitosan beads
dyes
glutaraldehyde; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Powiązania:: https://bibliotekanauki.pl/articles/1035401.pdf Link otwiera się w nowym oknie
Opis:: The study was established to analyze the effectiveness of Reactive Black (RB5) and Basic Green (BG4) dyes adsorption onto chitosan beads and onto chitosan beads cross-linked with glutaraldehyde depending on the initial dye concentration in the solution (1, 5, 100 and 200 mg/dm3). It demonstrated that both the initial concentration of dye in the solution as well as the type of adsorbent affected the effectiveness of the adsorption process. An increase in the initial dye concentration in the solution was increasing adsorption effectiveness, irrespective of the type of dye and adsorbent. The cross-linking of chitosan beads with glutaraldehyde turned out to be beneficial only in the case of the RB5 dye.
Dostawca treści:: Biblioteka Nauki

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