scholarly journals A Simple Approach to Produce Tailor-Made Chitosans with Specific Degrees of Acetylation and Molecular Weights

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2415
Author(s):  
Luis-Felipe Sánchez ◽  
Jimmy Cánepa ◽  
Suyeon Kim ◽  
Javier Nakamatsu

Chitin is a structural polysaccharide that is found in crustaceans, insects, fungi and some yeasts. Chitin deacetylation produces chitosan, a well-studied biopolymer with reported chemical and biological properties for diverse potential applications for drug delivery, metal ion absorption, scaffolds and tissue engineering. Most known properties of chitosan have been determined from samples obtained from a variety of sources and in different conditions, this is, from chitosans with a wide range of degrees of N-acetylation (DA) and molecular weight (MW). However, as for any copolymer, the physicochemical and mechanical characteristics of chitosan highly depend on their monomer composition (DA) and chain size (MW). This work presents a simple methodology to produce chitosans with specific and predictive DA and MW. Reaction with acetic anhydride proved to be an efficient method to control the acetylation of chitosan, DAs between 10.6% and 50.6% were reproducibly obtained. In addition to this, MWs of chitosan chains were reduced in a controlled manner in two ways, by ultrasound and by acidic hydrolysis at different temperatures, samples with MWs between 130 kDa and 1300 kDa were obtained. DAs were determined by 1H-NMR and MWs by gel permeation chromatography.

2007 ◽  
Vol 32 (3) ◽  
pp. 827-830
Author(s):  
Takao Mitsui ◽  
Masaaki Sugiyamat ◽  
Hiroshi Orihara ◽  
Yong Hona ◽  
Yuji Soejima ◽  
...  

2017 ◽  
Vol 71 (0) ◽  
pp. 0-0
Author(s):  
Paulina Dębek ◽  
Agnieszka Feliczak-Guzik ◽  
Izabela Nowak

The general tendency towards the miniaturization of technological systems and materials has prompted intensive development of nanotechnology. It is a quickly developing area of science devoted to the production and application of nanomaterial structures defined as those whose one size does not exceed 100 nm. Nanostructures have been found to show new physical, chemical and biological properties often better than the corresponding materials made of particles of micrometric or macrometric sizes, so they have become of great interest in many areas of industry as well as other areas [22], such as medicine and cosmetology. According to literature and Scopus database, Fig. 1, the most popular nanostructures used in medicine and cosmetology, besides silver and gold nanoparticles, are those of other transition metals such as platinum, palladium or ruthenium. This paper is concerned with the wide range of present and potential applications of nanomaterials in medicine and cosmetology.


Author(s):  
E. CLINTON TEXTER ◽  
HIGINO C. LAURETA ◽  
CHING-CHUNG CHOU

2017 ◽  
Vol 5 (28) ◽  
pp. 6917-6922 ◽  
Author(s):  
Jiayi Zhu ◽  
Qian Lu ◽  
Chiyun Chen ◽  
Jianqiang Hu ◽  
Jinbin Liu

One-step strategy to fabricate a luminescent sponge-like network of AuNPs with a high capacity for heavy metal ion absorption.


2020 ◽  
Vol 15 (6) ◽  
Author(s):  
Wei Dong ◽  
Ling Yang ◽  
Fuping Qian ◽  
Zhong Lv ◽  
Chunhua Wu ◽  
...  

2001 ◽  
Vol 17 (2) ◽  
pp. 177-183 ◽  
Author(s):  
Andreas Rolfs ◽  
Matthias A. Hediger

2007 ◽  
Vol 342-343 ◽  
pp. 745-748
Author(s):  
Mi Sook Kim ◽  
Yoon Jeong Choi ◽  
Gun Woo Kim ◽  
In Sup Noh ◽  
Yong Doo Park ◽  
...  

Though hyaluronic acid (HA)-based hydrogel has drawn great attention in biomedical society, it’s long molecular weights sometimes have been problematic due to its difficulty in handling. After reduction of its high molecular weight into smaller sizes with various concentrations of hydrogen chloride solutions, its chemical and biological properties have been examined by changes in viscosity, FTIR spectroscopy and gel permeation chromatography as well as cellular interactions. While FTIR analysis indicated maintenance of its original chemical structures, its viscosity has been remarkably reduced and its extent was dependent upon the employment of acid concentrations. After controlling its molecular weight to approximately 100 kDa and coupling of aminopropymethacrylate to the treated HA, we evaluated in vitro cellular interactions and cell proliferations of the HA-poly(ethylene oxide) (PEO) hydrogel.


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