Cellulose derivatives chitosan

Semi-flexible coil cellulose derivatives, chitosans... 

Cellulose derivatives Chitosans Gelatin Sodium carboxymethylcellulose (NaCMC) Methylcellulose (MC) Hydroxypropyl methylcellulose (HPMC) Hydroxypropyl cellulose (HPC) Hydroxyethyl cellulose (HEC)... 

Ridietal., 2014). PNIPAM shrinks and becomes hydrophobic at temperatures above its LCST, and turns into swollen and hydrophilic state below its LCST (Tekin et al 2011). Natural polymers have also shown thermoresponsive behaviors such as cellulose derivatives, chitosan, dextran, or even some proteins (BQouda and Mikos, 2008). 

Some experimental results obtained from NMR and EPR spectroscopies in a series of polymer electrolytes based on cellulose derivatives, chitosan, starch, agar and other natural polymers are now presented. 

Mucoadhesives are generally macromolecular organic polymers made from natural (gelatin, agarose, chitosan, hyaluronic acid) or synthetic polymers (polyvinylpyrrolidone (PVP), polyacrylates, polyvinyl alcohol, cellulose derivates). They possess hydrophilic groups that can... 

Research on nasal powder drug delivery has employed polymers such as starch, dextrans, polyacrylic acid derivatives (e.g., carbopol, polycarbophil), cellulose derivatives (microcrystalline cellulose, semicrystalline cellulose, hydroxypropylmethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose), chitosan, sodium alginate, hyaluronans, and polyanhydrides such as poly(methyl vinyl ether-co-maleic anhydride) (PVM/MA). Many of these polymers have already been used as excipients in pharmaceutical formulations and are often referred to as first-generation bioadhesives [38-45], In nasal dry powder a single bioadhesive polymer or a... 

ACS Polymeric Materials Science and Engineering. Fall Meeting 1998. Volume 79. Conference proceedings. Boston, Mas., 23rd-27th Aug. 1998, p.220-1. 012 ANTIMICROBIAL PROPERTIES OF QUATERNARY AMMONIUM CELLULOSE AND CHITOSAN DERIVATIVES Daly W H Guerrini M M Louisiana, State University... 

Hyaluronic acid is a linear polysaccharide formed from disaccharide units containing N-acetyl-D-glucosamine and glucuronic acid. Since it is present in almost all biological fluids and tissues, hyaluronic acid-based materials are very useful in biomedical applications. After cellulose, chitin is the second most abundant natural polysaccharide resource on earth. Chitin and its de-acetylated derivative chitosan are natural polymers composed of N-acetylglucosamine and glucosamine. Both chitin and chitosan have excellent properties such as biodegradability, biocompatibility, non-toxicity, hemostatic activity and antimicrobial activity. Chitin and its derivatives are widely used in various fields of medicine. 

Daly, W. H., and Guerrini, M. M. (1998). Antimicrobial properties of quaternary ammonium cellulose and chitosan derivatives, Polym. Mater. Set Eng., 79,220-221. 

Natural polymers have also been used as thermo-sensitive hydrogels, either on their own or in combination with other synthetic polymers. Popular natural polymers include chitosan, cellulose derivatives, dextran, xyloglucan and gelatin (Klouda and Mikos 2008). Chitosan is a polysaccharide derived from the shells of crustaceans and is produced by deacetylation of chitin, basically through the removal of the acetyl group using a concentrated NaOH solution (Fig. 11.5). The main advantage of chitosan for medical and pharmaceutical applications is its biocompatibility and inertness when in contact with human cells (Kumar et al. 

Besides the naturally occurring cationic PS chitin and chitosan, a huge variety of semi-synthetic products is available, which are based on anchoring cationic groups onto the polysaccharide backbone. Examples include cationic starch and cationic cellulose derivatives, which are widely used for industrial purposes (cationic starch in paper ) and also in medical applications (cationic cellulose as additives, e.g. JR-400 and Quatrisoft LM-200 in hygienic products). However, applications in regenerative medicine are rather poorly developed for these materials and therefore a discussion is excluded at this point. 

After cellulose, it is the second most abundant natural polymer found in the nature. Figure 8.9 shows the exoskeleton structure of crab shells, where chitin was derived. Chitin can also be synthesized artificially through chitinase-catalyzed polymerization of a chitobiose oxazoline derivative. Chitosan, a very important derivative of chitin, is obtained... 

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