► Carboxymethyl chitosan, a multi functional polymer derivative of chitosan. ► Synthesis characterization and physiochemical properties of carboxymethyl chitosan. ► Carboxymethyl chitosan-based ...systems for biomedical applications. ► Application in drug delivery, wound healing, tissue engineering, and gene therapy.
This review outlines the recent developments on carboxymethyl chitosan-based bio-medical applications. Carboxymethyl chitosan, a water soluble derivative of chitosan, with enhanced biological and physicochemical properties compared to chitosan, has emerged as a promising candidate for different biomedical applications. Introducing small chemical groups like carboxymethyl to the chitosan structure can drastically increase the solubility of chitosan at neutral and alkaline pH values without affecting their characteristic properties. Due to improved biocompatibility, high moisture retention ability more viscosity and enhanced antimicrobial property of carboxymethyl chitosan than chitosan makes it promising candidate for hydrogels and wound healing applications. The biodegradability and biocompatibility of carboxymethyl chitosan has significant interest with application as biomaterial for tissue engineering. Apart from this, the easy of carboxymethyl chitosan can be easily processed into nanoparticles so it has shown promise for drug delivery, bioimaging, biosensors and gene therapy applications. The contribution of carboxymethyl chitosan to green chemistry in the recent years has also been given in detail. This review will focus on preparative methods and physicochemical and biological properties of carboxymethyl chitosan with particular emphasis on biomedical and pharmaceutical applications of this derivative of chitosan.
As a natural polysaccharide, chitosan has good biocompatibility, biodegradability and biosecurity. The hydroxyl and amino groups present in its structure make it an extremely versatile and chemically ...modifiable material. In recent years, various synthetic strategies have been used to modify chitosan, mainly to solve the problem of its insolubility in neutral physiological fluids. Thus, derivatives with negative or positive fixed charge were synthesized and used to prepare innovative drug delivery systems. Positively charged conjugates showed improved properties compared to unmodified chitosan. In this review the main quaternary ammonium derivatives of chitosan will be considered, their preparation and their applications will be described to evaluate the impact of the positive fixed charge on the improvement of the properties of the drug delivery systems based on these polymers. Furthermore, the performances of the proposed systems resulting from in vitro and ex vivo experiments will be taken into consideration, with particular attention to cytotoxicity of systems, and their ability to promote drug absorption.
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•A double-network polysaccharide-based composite hydrogel was developed.•Mechanical properties of the hydrogel were enhanced by grafted methacrylate groups.•The hydrogel ...functionalized with collagen peptide promoted cell proliferation and wound healing.
Effective wound dressings are of great significance in preventing infections and promoting wound healing. However, most existing hydrogel dressings have an inadequacy in either mechanical performance, biological activities, or versatilities. Here we presented a double-network cross-linked polysaccharide-based hydrogel composed of collagen peptide-functionalized carboxymethyl chitosan (CS) and oxidized methacrylate sodium alginate (SA). The hydrogel possessed interconnected porous morphologies, suitable swelling ratios, excellent mechanical properties, and favorable biocompatibility. Meanwhile, the in vivo studies using a mouse full-thickness skin defect model showed that the double-network CS/SA hydrogel significantly accelerated wound healing by regulating the inflammatory process, promoting collagen deposition, and improving vascularization. Therefore, the functionalized double-network hydrogel should be a potential candidate as wound dressings
Antibiotics played an important role in controlling the development of enteric infection. However, the emergence of antibiotic resistance and gut dysbiosis led to a growing interest in the use of ...natural antimicrobial agents as alternatives for therapy and disinfection. Chitosan is a nontoxic natural antimicrobial polymer and is approved by GRAS (Generally Recognized as Safe by the United States Food and Drug Administration). Chitosan and chitosan derivatives can kill microbes by neutralizing negative charges on the microbial surface. Besides, chemical modifications give chitosan derivatives better water solubility and antimicrobial property. This review gives an overview of the preparation of chitosan, its derivatives, and the conjugates with other polymers and nanoparticles with better antimicrobial properties, explains the direct and indirect mechanisms of action of chitosan, and summarizes current treatment for enteric infections as well as the role of chitosan and chitosan derivatives in the antimicrobial agents in enteric infections. Finally, we suggested future directions for further research to improve the treatment of enteric infections and to develop more useful chitosan derivatives and conjugates.
•Preparation of ZnO nanoparticles by in situ generated in carboxymethyl chitosan.•ZnO was incorporated into chitosan multilayer films to improve properties.•Water vapor resistance was improved by the ...addition of ZnO and sodium alginate.•Mechanical properties and antibacterial activity were improved.•The film with prepared ZnO (0.05 g/g sodium alginate) had a better preservation effect.
To deal with serious environmental pollution resulting from plastic packaging materials, biodegradable films using chitosan (CS) are gaining considerable increase gradually. However, chitosan films lack important properties to meet the preserved demands. This study aimed to develop new bio-based films incorporated with carboxymethyl chitosan-ZnO (CMCS-ZnO) nanoparticles and sodium alginate (SA) to overcome the weakness of CS films. CMCS-ZnO nanoparticles were successfully synthesized in the matrix of CMCS through direct precipitation method, which showed an average diameter of 100 nm. Multilayer films with CS film as the outer layer and SA film as the inner layer were prepared by solution casting method. The addition of CMCS-ZnO nanoparticles led to enhanced tensile strength, and to better water vapor resistance. The as-prepared films exhibited distinctive antibacterial activity against S. aureus and E. coli. The results suggested that the as-prepared film is expected to be a promising material for food packaging.
In this review, we present the data on the natural occurrence of chitin and its partially or fully deacetylated derivative chitosan, as well as their properties, methods of modification, and ...potential applications of derivatives with bactericidal, fungicidal, and antioxidant activities. The structure and physicochemical characteristics of the polymers, their functions, and features of chitin microbial synthesis and degradation, including the processes occurring in nature, are described. New data on the hydrolytic microorganisms capable of chitin degradation under extreme conditions are presented. Special attention is focused on the effect of physicochemical characteristics of chitosan, including molecular weight, degree of deacetylation, polydispersity index, and number of amino group derivatives (quaternized, succinyl, etc.) on the antimicrobial and antioxidant properties of modified polymers that can be of particular interest for biotechnology, medicine, and agriculture. Analysis of the available literature data confirms the importance of fundamental research to broaden our knowledge on the occurrence of chitin and chitosan in nature, their role in global biosphere cycles, and prospects of applied research aimed at using chitin, chitosan, and their derivatives in various aspects of human activity.
•Response surface-optimized preparation of anthocyanin-loaded chitosan nanoparticles.•Box-Behnken design for high encapsulation efficiency and small particle size.•First anthocyanin nanoparticles of ...carboxymethyl chitosan and chitosan hydrochloride.•Chitosan nanoparticles delayed anthocyanin degradation in simulated GI fluid.•Chitosan nanoparticles increased anthocyanin storage stability in a model beverage.
The optimal preparation parameters to create anthocyanin-loaded chitosan nanoparticles was predicted using response surface methodology (RSM). A Box-Behnken design was used to determine the preparation parameters that would achieve the preferred particle size and high encapsulation efficiency. The result suggested that the optimized conditions were 2.86mg/mL carboxymethyl chitosan (CMC), 0.98mg/mL chitosan hydrochloride (CHC) and 5.97mg anthocyanins. Using the predicted amounts, the experimentally prepared particles averaged 219.53nm with 63.15% encapsulation efficiency. The result was less than 5% different than the predicted result of 214.83nm particle size and 61.80% encapsulation efficiency. Compared with the free anthocyanin solution, the anthocyanin-loaded chitosan nanoparticles showed a slowed degradation in simulated gastrointestinal fluid. Compared with the free anthocyanin solutions in a model beverage system, the stability of the anthocyanins was increased in the anthocyanin-loaded chitosan nanoparticles.
•This study aims to evaluate the contribution of chitosan nanoparticles to enhance the antimicrobial activity.•Nisin and Natamycin will be applied either in the free-state or loaded on chitosan ...nanoparticles.•Disc diffusion assay, Lb. helveticus crude CFS recorded the highest potency against all bacterial indicators.•The recorded MIC values were found to be higher in case of tested bacteria than yeast and fungus.•CFS with HS–GC–MS showed that Lb. helveticus produces a wide range of antimicrobial& health-promoting substances.
This research attempted to inspect the contribution of lactic acid bacteria (LAB) with nanoparticle application in antimicrobial enhancement. Seven lactic acid cultures-free supernatants (CFSs) in both free and nanoparticles-loaded states were examined against seven foodborne microorganisms. Lactobacillus helveticus followed by Lactobacillus Plantarum possessed considerable antimicrobial activity. Headspace GC–MS characterization of Lactobacillus helveticus CFS identified a mixture of antimicrobial and health-promoting compounds. Minimal inhibitory concentration (MIC) values for tested Gram-positive bacteria represented 50% of that for Gram-negative bacteria, 20% and 7.35% of those for fungus and yeast respectively. Nanoparticles were prepared through chitosan-tripolyphosphate nanoparticle formation giving nanospheres from in the range from 5 to 10 nm, and narrow size distribution. CFS-loaded chitosan nanoparticles (CS-NPs) significantly enhanced the overall inhibition zone diameter, as well as, the decline in MIC values for Salmonella enterica (50%) and Penicillium chrysogenum (12.5%) was observed. Lactobacillus helveticus CFS, however, displayed lower antimicrobial activity vs. nisin and natamycin, it has both antibacterial and antifungal promising activities.
Chitosan is the second abundant biopolymer present on earth after cellulose. Chitosan is extracted from the shells of shrimp and other crustaceans. Several methods were reported for its extraction, ...but the most commercial is the deacetylation of chitin. Chitosan as a biopolymer has numerous applications and uses. But, its mechanical, chemical and biological characteristics can be enhanced by modification of its chemical structures. Several modification methods and derivatives were reviewed in the literatures, and several were collected in this review. The reviewed modified chitosan derivatives herein were five types of derivatives. The first is substituted chitosan derivatives including thiolated, phosphorylated, and N-phthaloylated derivatives. The second is crosslinked chitosan derivatives including chitosan-glutaraldehyde, chitosan-ethylene diamine tetraacetic acid, and chitosan-epichlorohydrin derivatives. The third is carboxylic acid derivatives of chitosan obtained from carboxyalkylation, acrylation, methacrylation, and benzoylation of chitosan. The fourth is ionic chitosan derivatives including highly cationic and sulfated derivatives. The last is bounded chitosan to specific molecules including cyclodextrin, thiosemicarbazone, dioxime, and crown ether precursors. The review also highlights the reported advantages and applications of the modified chitosan and the synthetic routes of the biopolymer modification.
•Chitosan biopolymer can be functionalized by numerous function groups.•Functionalization can be addition, coupling, and crosslinking.•Modification of chitosan upgrades its potential applications.
Chitosan, derived from chitin, has many desirable biomedical attributes.
This review aims to explore different sources of chitin and methods of chitosan production with industrial consideration. This ...article first discussed different sources of chitin for industrial scale production, with considerations given to both their environmental impacts and commercialization potential. Secondly, this article reviews the two categories of chitosan preparation – chemical methods and biological methods - based on existing publications which used lobster by-products as a feedstock source. The mechanisms of the chemical methods are firstly summarized, and then the different chemical agents and reaction parameters used are discussed. Next, both enzymatic and fermentation-based approaches are reviewed under biological methods and compared with chemical methodologies, with lactic fermentation methods as the major focus. This article concludes that lobster cephalothorax could be an ideal source for chitosan preparation on an industrial scale; and chemical methods involve simpler processing overall, while producing chitosan with stronger bioactivities because of the lower molecular weight (MW) and higher degree of deacetylation (DD) achieved by the products. Moreover, due to biological methods inevitably necessitating further chemical processing, an approach involving some unconventional chemical methods has been regarded as a more suitable strategy for industrial scale chitosan production.
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