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Wyszukujesz frazę "chitosan derivatives" wg kryterium: Temat


Wyświetlanie 1-6 z 6
Tytuł:
Modyfikacja chitozanu : krótki przegląd
Modification of chitosan : a concise overview
Autorzy:
Ostrowska-Czubenko, J.
Pieróg, M.
Gierszewska, M.
Powiązania:
https://bibliotekanauki.pl/articles/172373.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Chemiczne
Tematy:
chitozan
modyfikacja chitozanu
pochodne chitozanu
sieciowanie
chitosan
chitosan modification
chitosan derivatives
crosslinking
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
Źródło:
Wiadomości Chemiczne; 2016, 70, 9-10; 657-679
0043-5104
2300-0295
Pojawia się w:
Wiadomości Chemiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Express analysis of chitosan and its derivatives by gel electrophoresis
Autorzy:
Konovalova, Mariya
Shagdarova, Balzhima Ts.
Zubov, Vitaliy
Svirshchevskaya, Elena
Powiązania:
https://bibliotekanauki.pl/articles/1034210.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Tematy:
agarose gel electrophoresis
chitosan
chitosan derivatives
degree of deacetylation
molecular weight
Opis:
Chitosan is one of the most promising polymers for biomedical applications due to its unique properties, such as its biocompatibility, low toxicity, biodegradation, and the presence of reactive amino and hydroxyl groups. Analysis of physicochemical properties of chitosan and its derivatives is a time-consuming process and requires expensive equipment and large amounts of the sample. This paper proposes a method for express analysis of the molecular weight (MW), the degree of deacetylation (DD), the substitution degree (SD), and the charge of chitosan and its derivatives using agarose gel electrophoresis under acidic and neutral conditions with Coomassie staining. Positively charged chitosan samples required acidic Tris Acetate-EDTA (TAE) buffer to move in the gel. The electrophoretic mobility of chitosan depended on MW, DD, SD, and the chitosan charge. Based on the dependences obtained by the proposed method, the MW and DD of commercial chitosan samples were determined. Express analysis of chitosan and its derivatives in agarose gel can be used to monitor the reactions of chitosan modification and to analyse samples with unknown characteristics.
Źródło:
Progress on Chemistry and Application of Chitin and its Derivatives; 2019, 24; 84-95
1896-5644
Pojawia się w:
Progress on Chemistry and Application of Chitin and its Derivatives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synteza i ocena możliwości zastosowania niektórych pochodnych chitozanu w przemyśle skórzanym. Część I, Przegląd literatury
Synthesis and evaluation of the possibility of using selected chitosan derivatives in the leather industry. Part I, Literature review
Autorzy:
Szuster, L.
Wyrębska, Ł.
Gendaszewska, D.
Powiązania:
https://bibliotekanauki.pl/articles/412689.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Skórzanego
Tematy:
chitozan
pochodne chitozanu
poliglikole
substancje antybakteryjne
chitosan
chitosan derivatives
polyglycols
antibacterial substances
Opis:
Wzrastające obawy użytkowników obuwia przed chorobami stóp stwarzają nowe wyzwania przemysłowi obuwniczemu. Dlatego poszukiwane są nieszkodliwe dla człowieka substancje antybakteryjne, które będą skutecznie działać po zaaplikowaniu na wyroby skórzane. Takimi substancjami mogą być kopolimery oparte o naturalny polisacharyd - chitozan i jego poliglikolowe pochodne. W pracy przedstawiono aktualny stan wiedzy w zakresie modyfikacji chitozanu, prowadzący do otrzymania kopolimerów, stwarzających możliwość zastosowań ich w przemyśle skórzanym.
Increasing concerns of footwear users against foot diseases create new challenges for the footwear industry. Therefore, the antibacterial substances that will be effective after application to leather products and safe for human are still searched. Such substances may be copolymers based on natural polysaccharide - chitosan and its polyglycol derivatives. The paper presents the current state of knowledge in the field of chitosan modification leading to obtaining copolymers that may have potential applications in the leather industry.
Źródło:
Technologia i Jakość Wyrobów; 2018, 63; 105-118
2299-7989
Pojawia się w:
Technologia i Jakość Wyrobów
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Large size dna in vitro and in vivo delivery using chitosan transfection
Autorzy:
Sankov, Vladislav
Shagdarova, Balzhima
Varlamov, Valerii
Esipov, Roman
Svirshchevskaya, Elena
Powiązania:
https://bibliotekanauki.pl/articles/1034546.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Tematy:
DNA delivery
chitosan derivatives
hydrophobic groups
рRFP pmKate2 reporter plasmid
Opis:
In modern medicine, many diseases can be treated using gene therapy, which requires a DNA delivery system to prevent DNA from degradation and to transport it to the cells. Liposomal reagents are expensive for such a therapy and new inexpensive biodegradable DNA carriers are required. Chitosan (Ch) is a cationic polymer with promising potency for gene delivery. Some Ch derivatives have been shown to efficiently transfect mammalian cells in vitro. However, there are many inconsistencies in the literature concerning the effectiveness of Ch systems for in vivo gene transfer. The aim of this work was to develop a Ch-based vector for in vivo delivery of a large-size DNA fragment coding for the far-red fluorescent protein (RFP). Among several Ch derivatives, hexanoyl-Ch (HCh) with a molecular weight of 20 kDa effectively transfected cells in vitro. Intratumoural injection of polyplexes in colon and lung tumours resulted in local expression of RFP in tumours.
Źródło:
Progress on Chemistry and Application of Chitin and its Derivatives; 2017, 22; 190-200
1896-5644
Pojawia się w:
Progress on Chemistry and Application of Chitin and its Derivatives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biomaterials based on chitosan and its derivatives to prevent adhesion formation
Autorzy:
Konovalova, Mariya
Tsaregorodtseva, Daria
Svirshchevskaya, Elena
Powiązania:
https://bibliotekanauki.pl/articles/2129557.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Tematy:
biomaterials
chitosan
derivatives of chitosan
polymers
prevention of adhesions
Opis:
An increase in the number and volume of surgical interventions leads to an increase in the frequency of postoperative adhesions. The development of the adhesion process in the abdominal cavity causes pain, a decrease in the quality of life of patients, a violation of the reproductive function of women as well as acute adhesion intestinal obstruction. Recently, polymer biomaterials, including those based on chitosan, have been widely used for the prevention of adhesions. Due to their biocompatibility and biodegradation ability, they do not require repeated operations to extract the material. It is believed that these materials act as barriers, physically separating the damaged surfaces. The molecular mechanism of their action is still poorly understood. In this review, the main mechanisms of adhesion formation, as well as ways to prevent them with the help of materials based on chitosan and its derivatives, are discussed
Źródło:
Progress on Chemistry and Application of Chitin and its Derivatives; 2021, 26; 11-22
1896-5644
Pojawia się w:
Progress on Chemistry and Application of Chitin and its Derivatives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Protein delivery by nanoparticles formed by chitosan-n-acyl derivatives
Autorzy:
Zubareva, Anastasia А.
Ilyina, Alla.V.
Levov, Аlexandr N.
Zueva, Vera S.
Svirshchevskaya, Еlena V.
Varlamov, Valery P.
Powiązania:
https://bibliotekanauki.pl/articles/1035474.pdf
Data publikacji:
2011
Wydawca:
Sieć Badawcza Łukasiewicz - Polskie Towarzystwo Chitynowe
Tematy:
N-acyl derivatives of chitosan
chitosan nanoparticles
ionic gelation
protein delivery
Opis:
Biodegradable nanoparticulated carriers have important potential applications for administration of therapeutic proteins and peptides. Chitosan based nanoparticles have attracted attention due to their biological properties such as biodegrability and biocompatibility. However, chitosan nanoparticles are not stable in colloid form. Therefore, to increase the stability of these particles is an important problem. The aim of this work was to obtain stable nanoparticles formed by N-acyl derivatives of chitosan by ionic gelation and to investigate their ability to interact with acidic, neutral and basic proteins.
Źródło:
Progress on Chemistry and Application of Chitin and its Derivatives; 2011, 16; 61-70
1896-5644
Pojawia się w:
Progress on Chemistry and Application of Chitin and its Derivatives
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

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