نتایج جستجو برای: chitosan

تعداد نتایج: 17212  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه محقق اردبیلی - دانشکده علوم 1392

مهندسی بافت ترکیبی از سلول و داربست سه بعدی جهت ترمیم بافت آسیب دیده یا از بین رفته ی ماهیچه است. در این راستا, نانو داربست های کامپوزیت نانولوله های کربنی و کایتوزان و هیدرکسی آپاتیت، نانولوله های کربنی و کایتوزان و داربست کایتوزان با روش freeze dryingتهیه شد. داربست های تهیه شده، از لحاظ خصوصیات سطحی، درصد تخلخل، اندازه ی منافذ، نحوه ی توزیع منافذ، رفتار تخریب پذیریو ترکیب تشکیل دهنده ی داربس...

2006
A. M. A. Nada S. Kamel E. S. Abd El-Sayed

Chitosan was prepared from crab shell. Different derivatives of chitosan e.g. phosphate, cyanoethyl and carboxymethyl chitosan are prepared. Molecular structure of chitosan and its derivatives was fallowed by infrared spectroscopy. A new band at 1715cm -1 (carboxyl group), at 2253cm -1 (cyano group) and at 1200cm -1 for (c-o-p) in spectra of carboxymethyl chitosan, cyanoethyl chitosan and chito...

Journal: :Journal of microencapsulation 2006
K G Desai C Liu H J Park

In this paper, the effect of chitosan molecular weight on the characteristics (size, encapsulation efficiency, zeta potential, surface morphology and release rate) of vitamin C encapsulated tripolyphosphate cross-linked chitosan (TPP-chitosan) microspheres. The molecular weight of chitosan had a noticeable influence on the size, encapsulation efficiency, zeta potential, surface morphology and c...

2016
Jing Wang Ji-Zhou Jiang Wei Chen Zheng-Wu Bai

The data shown in this article are related to the subject of an article in Carbohydrate Polymers, entitled "Synthesis and characterization of chitosan alkyl urea" [1]. 1H NMR and 13C NMR spectra of chitosan n-octyl urea, chitosan n-dodecyl urea and chitosan cyclohexyl urea are displayed. The chemical shifts of proton and carbon of glucose skeleton in these chitosan derivatives are designated in...

2011
K. Sun Z. H. Li

Chitosan is soluble in most acids. The protonation of the amino groups on the chitosan backbone inhibits the electrospinnability of pure chitosan. Recently, electrospinning of nanofibers based on chitosan has been widely researched and numerous nanofibers containing chitosan have been prepared by decreasing the number of the free amino groups of chitosan as the nanofibiers have enormous possibi...

2014
Alina Sionkowska Beata Kaczmarek Katarzyna Lewandowska B. Kaczmarek K. Lewandowska

Chitosan is widely applied in biomedical and cosmetic fields. For this reason, there is a need to modify this biopolymer to achieve new properties of chitosan-based materials. The properties of chitosan can be modified by several cross-linking methods. In this work, we used the chemical cross-linking of chitosan with tannic acid, after which cross-linked chitosan was shaped into a 3D structure ...

Journal: :European journal of pharmaceutics and biopharmaceutics : official journal of Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik e.V 2008
Chunqiang Guo Richard A Gemeinhart

Polyelectrolyte-coated nanoparticles or microparticles interact with bioactive molecules (peptides, proteins or nucleic acids) and have been proposed as delivery systems for these molecules. However, the mechanism of adsorption of polyelectrolyte onto particles remains unsolved. In this study, cationic poly(lactide-co-glycolide) (PLGA) nanoparticles were fabricated by adsorption of various conc...

Journal: :Molecules 2017
Qing Li Caili Zhang Wenqiang Tan Guodong Gu Zhanyong Guo

Chemical modification of chitosan is increasingly studied for its potential of providing new applications of chitosan. Here, a group of novel chitosan quaternary ammonium derivatives containing pyridine or amino-pyridine were designed and successfully synthesized through chemical modification of chitosan. Pyridine and amino-pyridine were used as functional groups to improve the antifungal activ...

Journal: :Biocontrol science 2006
Teruo Nakashima Masaru Matsuo Yuezhen Bin Yumiko Nakano Tomonori Kobayashi Sadao Komemushi Yoshikazu Sakagami

Chitin, chitosan and quaternary chitosan films were prepared, and the mechanical properties and the antibacterial activities of chitosan and quaternary chitosan films were evaluated. The tensile strength of chitin films was 30-40% lower than that of chitosan films, but the crystallinity of the former was much higher than those of the latter. A detailed analysis of the crystallinity and orientat...

Journal: :Journal of controlled release : official journal of the Controlled Release Society 2002
Jue-Yeon Lee Sung-Heon Nam Su-Yeon Im Yoon-Jeong Park Yong-Moo Lee Yang-Jo Seol Chong-Pyoung Chung Seung-Jin Lee

For the purpose of obtaining high bone forming efficacy, development of chitosan was attempted as a tool useful as a scaffolding device. Porous chitosan matrices, chitosan-poly(L-lactide) (PLLA) composite matrices and chitosan coated on PLLA matrices were dealt with in this research. Porous chitosan matrix was fabricated by freeze-drying and cross-linking aqueous chitosan solution. Porous chito...

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