Chitosan has garnered much interest due to its properties and possible applications. Every year the number of publications and patents based on this polymer increase. Chitosan exhibits poor ...solubility in neutral and basic media, limiting its use in such conditions. Another serious obstacle is directly related to its natural origin. Chitosan is not a single polymer with a defined structure but a family of molecules with differences in their composition, size, and monomer distribution. These properties have a fundamental effect on the biological and technological performance of the polymer. Moreover, some of the biological properties claimed are discrete. In this review, we discuss how chitosan chemistry can solve the problems related to its poor solubility and can boost the polymer properties. We focus on some of the main biological properties of chitosan and the relationship with the physicochemical properties of the polymer. Then, we review two polymer applications related to green processes: the use of chitosan in the green synthesis of metallic nanoparticles and its use as support for biocatalysts. Finally, we briefly describe how making use of the technological properties of chitosan makes it possible to develop a variety of systems for drug delivery.
Marine resources are well recognized for their biologically active substances with great potential applications in the cosmeceutical industry. Among the different compounds with a marine origin, ...chitin and its deacetylated derivative-chitosan-are of great interest to the cosmeceutical industry due to their unique biological and technological properties. In this review, we explore the different functional roles of chitosan as a skin care and hair care ingredient, as an oral hygiene agent and as a carrier for active compounds, among others. The importance of the physico-chemical properties of the polymer in its use in cosmetics are particularly highlighted. Moreover, we analyse the market perspectives of this polymer and the presence in the market of chitosan-based products.
Chitin and chitosan demand is growing very fast due to interest from industries such as pharmaceutical, cosmetic, agricultural and others. New sources for chitin and chitosan isolation are being ...extensively searched to fulfil this demand. In this paper,
a Baltic benthic crustacean, is evaluated as a source for chitin and chitosan isolation. Chitin and chitosan yield from
were 14.8 and 8.2%, respectively, in a similar range to other sources. Samples were characterized in terms of physicochemical properties (acetylation degree, molecular weight, thermal stability, and crystallinity) and two biological properties, antimicrobial activity and antioxidant activity were evaluated. Chitosan
exhibited antimicrobial activity against
but not against
An antioxidant activity of 20.98 TROLOX µmol equivalent/g polymer was detected for the chitosan sample. These properties are very promising for the use of this organism as a source for chitin and chitosan isolation in the biomedical field.
Venlafaxine controlled drug delivery systems using different matrixes have been tested to reduce undesirable side effects in the treatment of depression. The legal status of chitosan (Cs) in Pharmacy ...has dramatically improved after its acceptance as excipient in several
and, therefore, there is great interest in pharmaceutical formulations based on this polymer. In this paper, chitosan microcapsules cross-linked with sodium tripolyphosphate (TPP) for oral delivery of venlafaxine were formulated using the spray drying technique. The effect of chitosan physico-chemical properties, TPP concentration and TPP/Cs ratio on drug release was evaluated. The microcapsules were characterized in terms of size, zeta potential and morphology. The physical state of the drug was determined by X-ray diffraction (XRD) and the drug release from the microcapsules was studied in simulated gastric and intestinal fluids. The release pattern fitted well to the Peppas-Koersmeyer model with n exponents indicating anomalous transport.
This study reports the enzymatic depolymerization of chitosan by the chitosanolytic preparation of Bacillus licheniformis GA11. For this purpose, chitosanase production and biochemical ...characterization of the crude enzyme preparation from GA11 were firstly investigated. The highest chitosanase production was obtained in a culture medium containing 50.0 g/l of a mixture of soluble starch/shrimp shells/crab shells and 5.0 g/l tryptone, after incubation during 5 days, at 30 °C with a pHi of 6.0 and under continuous agitation at 200 rpm. Then, the chitosanolytic preparation, exhibiting maximum activity at 65 °C and pH 5.0, was used to hydrolyze chitosan, leading to various chitosan-depolymerization products (CDP) with different physicochemical characteristics. Finally, the antioxidant and antimicrobial potentials of CDP were evaluated, allowing to conclude that the molecular weight and the acetylation degree highly affect the biological activities of CDP.
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•Chitosanase medium production by Bacillus licheniformis was optimized.•The chitosanolytic preparation was biochemically characterized.•Enzymatic depolymerization of chitosan was investigated to produce varying Mw chitosan-depolymerization products (CDP).•The physicochemical characterization of CDP was carried out.•Antimicrobial and antioxidant activities of CDP were performed.
Chitin is the second most abundant biopolymer in nature after cellulose, and it forms an integral part of insect exoskeletons, crustacean shells, krill and the cell walls of fungal spores, where it ...is present as a high-molecular-weight molecule. In this study, we showed that a chitin oligosaccharide of lower molecular weight (tetramer) induced genes in
that are principally related to vegetative growth, development and carbon and nitrogen metabolism. Based on plant responses to this chitin tetramer, a low-molecular-weight chitin mix (CHL) enriched to 92% with dimers (2mer), trimers (3mer) and tetramers (4mer) was produced for potential use in biotechnological processes. Compared with untreated plants, CHL-treated plants had increased in vitro fresh weight (10%), radicle length (25%) and total carbon and nitrogen content (6% and 8%, respectively). Our data show that low-molecular-weight forms of chitin might play a role in nature as bio-stimulators of plant growth, and they are also a known direct source of carbon and nitrogen for soil biomass. The biochemical properties of the CHL mix might make it useful as a non-contaminating bio-stimulant of plant growth and a soil restorer for greenhouses and fields.
Chitosan derivatives with lower Mw were prepared by chemical depolymerization using hydrochloric acid. This modification improves functional and biological properties of shrimp chitosan and ...facilitates its utilizations. The obtained chitosan depolymerization products (CDP) were characterized in terms of molecular weight (Mw), degrees of acetylation (DA) and polymerization (DP), solubility, viscosity, crystallinity, and FTIR spectroscopy. High Mw-CDP (from 94.10 to 396.46 kDa) and low Mw-CDP (< 4.4 kDa), with a DP up to 7, were withdrawn at different hydrolysis times. It is clearly demonstrated that the viscosity, the DA, and the crystallinity decreased upon depolymerization, especially in low Mw-CDP, while solubility in water and acetic acid was highly improved. FTIR analysis showed similar spectra of chitosan and CDP. The antibacterial, antifungal, and antioxidant properties of CDP were investigated and demonstrated that they were related to its Mw. Indeed, as compared to chitosan, high Mw derivatives, especially C120, possess higher antibacterial and antifungal potentials. While, low Mw-CDP, especially H120, exhibited the highest antioxidant properties. Interestingly, the used chemical depolymerization process seems to be an efficient, simple, and easy method to produce bioactive chitosan derivatives with attractive characteristics to be applied in an industrial scale, especially as functional-food components.
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In this work, two chitosan samples from cuttlebone and squid pen are produced and characterized. We studied the formation of thermoresponsive hydrogels with β-glycerol phosphate and found proper ...formulations that form the hydrogels at 37 °C. Gel formation depended on the chitosan source being possible to produce the thermoresponsive hydrogels at chitosan concentration of 1% with cuttlebone chitosan but 1.5% was needed for squid pen. For the first time, these non-commercial chitosan sources have been used in combination with β-glycerol phosphate to prepare risperidone formulations for controlled drug delivery. Three types of formulations for risperidone-controlled release have been developed, in-situ gelling formulations, hydrogels and xerogels. The release profiles show that in-situ gelling formulations and particularly hydrogels allow an extended control release of risperidone while xerogels are not appropriate formulations for this end since risperidone was completely released in 48 h.
Methotrexate (MTX) administration is the gold standard treatment for rheumatoid arthritis (RA), but its effects are limited to preventing the progression of the disease. Therefore, effective ...regenerative therapies for damaged tissues are still to be developed. In this regard, MTX complexes of general molecular formula M(MTX)·xH2O, where M = Sr, Zn, or Mg, were synthesized and physicochemically characterized by TGA, XRD, NMR, ATR–FTIR, and EDAX spectroscopies. Characterization results demonstrated the coordination between the different cations and MTX via two monodentate bonds with the carboxylate groups of MTX. Cation complexation provided MTX with new bioactive properties such as increasing the deposition of glycosaminoglycans (GAGs) and alternative anti-inflammatory capacities, without compromising the immunosuppressant properties of MTX on macrophages. Lastly, these new complexes were loaded into spray-dried chitosan microparticles as a proof of concept that they can be encapsulated and further delivered in situ in RA-affected joints, envisioning them as a suitable alternative to oral MTX therapy.
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