Chitosan-based Materials Research Articles

Amino acid-functionalized chitosan beads for in vitro copper ions uptake in the presence of histidine

One of the hallmarks of Alzheimer's Disease (AD) is the anomalous binding involving amyloid-β (Aβ) peptide and metal ions, such as copper, formed through histidine (His) residues. Herein, adsorption experiments were performed to test the in vitro ability of chitosan to uptake copper ions in the presence of histidine. The characterization of the beads was assessed before and after the adsorption process by scanning electron microscope, X-ray diffraction and Fourier-transform infrared spectroscopy. Amino acid functionalization of chitosan-based beads promoted an increase in the copper ions adsorption capacity (2.47 mmol of Cu(II)/gram of adsorbent). Nevertheless, depending on the order of addition of histidine to the system, different adsorption behaviors were observed. The kinetics showed that, once the Cu(II)-His bond was established, functionalized beads were less efficient to capture Cu(II), which promoted a decrease in the overall adsorption capacity. However, when chitosan and histidine were simultaneously added to the Cu(II) solution, there was no decrease in adsorption capacity. To sum up, chitosan-based materials are an interesting model to provide a better understanding on the biomolecules‑copper interactions that occur in AD, as well as a possible chelating agent that can interfere in the bonds between Aβ residues and copper ions.

An Overview of the Design of Chitosan-Based Fiber Composite Materials

Chitosan composite fibrous materials continue to generate significant interest for wastewater treatment, food packaging, and biomedical applications. This relates to the relatively high surface area and porosity of such fibrous chitosan materials that synergize with their unique physicochemical properties. Various methods are involved in the preparation of chitosan composite fibrous materials, which include the modification of the biopolymer that serve to alter the solubility of chitosan, along with post-treatment of the composite materials to improve the water stability or to achieve tailored functional properties. Two promising methods to produce such composite fibrous materials involve freeze-drying and electrospinning. Future developments of such composite fibrous materials demands an understanding of the various modes of preparation and methods of structural characterization of such materials. This review contributes to an understanding of the structure–property relationships of composite fibrous materials that contain chitosan, along with an overview of recent advancements concerning their preparation.

The Physicochemical and Antibacterial Properties of Chitosan-Based Materials Modified with Phenolic Acids Irradiated by UVC Light.

This paper concerns the physicochemical properties of chitosan/phenolic acid thin films irradiated by ultraviolet radiation with wavelengths between 200 and 290 nm (UVC) light. We investigated the preparation and characterization of thin films based on chitosan (CTS) with tannic (TA), caffeic (CA) and ferulic acid (FA) addition as potential food-packaging materials. Such materials were then exposed to the UVC light (254 nm) for 1 and 2 h to perform the sterilization process. Different properties of thin films before and after irradiation were determined by various methods such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), differential scanning calorimeter (DSC), mechanical properties and by the surface free energy determination. Moreover, the antimicrobial activity of the films and their potential to reduce the risk of contamination was assessed. The results showed that the phenolic acid improving properties of chitosan-based films, short UVC radiation may be used as sterilization method for those films, and also that the addition of ferulic acid obtains effective antimicrobial activity, which have great benefit for food packing applications.

Development of chitosan-based bio-composited materials as a potential wound healing bandage in nursing care of caesarean section: In vivo evaluations

Now-a-days wound healing is a complex biological process without suitable natural biomaterials. Majority of wound dressing scaffolds were made of synthetic biomaterials which has least tendency to mimic natural tissues. In addition, the biocompatibility, biodegradation and mechanical strength of a many bio-composite doesn't possess antibacterial property. To overcome this notable properties and performance, we fabricated a unique multifunctional chitosan/gelatin/ZnO based scaffold bio-composite using freeze drying method. The newly developed scaffolds were characterized using Fourier Transform Infrared Spectroscopy, X-Ray Diffraction and Scanning Electron Microscopy. Further, the biological and mechanical properties of porous scaffold had good biocompatibility and tensile strength. As shown in cell viability, cell proliferation and cell adhesion were capable of rapid tissue regeneration process. Also antibacterial, invitro and invivo results revealed the scaffolds had a strong barrier protection. In results, our scaffold bio-composite showed good microporous structure, enhance tissue regeneration and enhance oxygen permeability at wound site.

Hemostatic and Tissue Regeneration Performance of Novel Electrospun Chitosan-Based Materials.

The application of chitosan (Ch) as a promising biopolymer with hemostatic properties and high biocompatibility is limited due to its prolonged degradation time, which, in turn, slows the repair process. In the present research, we aimed to develop new technologies to reduce the biodegradation time of Ch-based materials for hemostatic application. This study was undertaken to assess the biocompatibility and hemostatic and tissue-regeneration performance of Ch-PEO-copolymer prepared by electrospinning technique. Chitosan electrospinning membranes (ChEsM) were made from Ch and polyethylene oxide (PEO) powders for rich high-porous material with sufficient hemostatic parameters. The structure, porosity, density, antibacterial properties, in vitro degradation and biocompatibility of ChEsM were evaluated and compared to the conventional Ch sponge (ChSp). In addition, the hemostatic and bioactive performance of both materials were examined in vivo, using the liver-bleeding model in rats. A penetrating punch biopsy of the left liver lobe was performed to simulate bleeding from a non-compressible irregular wound. Appropriately shaped ChSp or ChEsM were applied to tissue lesions. Electrospinning allows us to produce high-porous membranes with relevant ChSp degradation and swelling properties. Both materials demonstrated high biocompatibility and hemostatic effectiveness in vitro. However, the antibacterial properties of ChEsM were not as good when compared to the ChSp. In vivo studies confirmed superior ChEsM biocompatibility and sufficient hemostatic performance, with tight interplay with host cells and tissues. The in vivo model showed a higher biodegradation rate of ChEsM and advanced liver repair.

Chitosan Natural Polymer Material for Improving Antibacterial Properties of Textiles.

In recent years, the textile industry has been seeking to develop innovative products. It is a good choice to organically combine materials with superior functional characteristics and commercial textiles to form products with excellent performance. In particular, textiles made of biological functional materials are often beneficial to human health, which is an interesting research direction. As a biopolymer material, chitosan has the advantages of strong availability, low cost, excellent safety, outstanding performance, etc., particularly the antibacterial property, and has broad application prospects in the textile field. This review provides an overview of the latest literature and summarizes recent innovations and state-of-the-art technologies that can add value to textiles. To this end, preparation of chitosan fiber, synthesis of chitosan nanofiber, antibacterial activity of chitosan fiber, antibacterial activity of chitosan nanofiber, etc., will be discussed. Furthermore, the challenges and prospects of chitosan-based materials used in textiles are evaluated. Importantly, this review can not only help researchers understand the development status of antibacterial textiles, but also help researchers discover and solve problems in this field through comparative reading.

Chitosan-Based Nanocomposite Polymeric Membranes for Water Purification-A Review.

During the past few years, researchers have focused their attention on developing innovative nanocomposite polymeric membranes with applications in water purification. Natural and synthetic polymers were considered, and it was proven that chitosan-based materials presented important features. This review presents an overview regarding diverse materials used in developing innovative chitosan-based nanocomposite polymeric membranes for water purification. The first part of the review presents a detailed introduction about chitosan, highlighting the fact that is a biocompatible, biodegradable, low-cost, nontoxic biopolymer, having unique structure and interesting properties, and also antibacterial and antioxidant activities, reasons for using it in water treatment applications. To use chitosan-based materials for developing nanocomposite polymeric membranes for wastewater purification applications must enhance their performance by using different materials. In the second part of the review, the performance’s features will be presented as a consequence of adding different nanoparticles, also showing the effect that those nanoparticles could bring on other polymeric membranes. Among these features, pollutant’s retention and enhancing thermo-mechanical properties will be mentioned. The focus of the third section of the review will illustrate chitosan-based nanocomposite as polymeric membranes for water purification. Over the last few years, researchers have demonstrated that adsorbent nanocomposite polymeric membranes are powerful, important, and potential instruments in separation or removal of pollutants, such as heavy metals, dyes, and other toxic compounds presented in water systems. Lastly, we conclude this review with a summary of the most important applications of chitosan-based nanocomposite polymeric membranes and their perspectives in water purification.

Recent Advances in the Synthesis, Properties, and Applications of Modified Chitosan Derivatives: Challenges and Opportunities.

Chitosan is a very well-known biocompatible and biodegradable polysaccharide consisting of β-(1-4)-linked glucosamine units, derived from the deacetylation of chitin. This unique biopolymer consists of primary amines as well as hydrophilic hydroxyl groups along with the chitosan backbone and has exceptional properties and wide applications. Numerous articles have been devoted to the preparation and properties of chitosan-based biomaterials, which have been demonstrated as beads, films, fibers (2D-scaffolds), gels, sponges (3D-scaffolds), and wound-healing materials. The unusual adsorption capacity of chitosan cross-linked polymer is demonstrated by trapping cations, anions, organic dyes, and pharmaceutical ingredients from wastewater. The most striking manifestations of flexibility in the preparation of these adsorbents have been critically reviewed, and their sorption efficiencies compared. Notably, these materials are also used as drug delivery carriers. Further, various metal-loaded chitosan-based nanocomposite materials have been used efficiently in organic catalytic reactions. As per the rich literature survey, such chitosan-based materials warrant further research due to their abundance, eco-friendliness, and effectiveness towards commercialization. The biotechnological aspects of chitosan may lead to promising low-cost materials and by-products of industrial and agricultural significance. The constant demand for potential adsorbents for the removal of pollutants, can be met by fine-tuning the structural properties of chitosan with appropriate cross-linkers or additives.

Polyhexanide and chlorhexidine loaded chitosan wound dressings

Introduction Wounds may be caused by surgery, trauma, or as a result of diseases such as diabetes. The disruption of the skin/internal tissues and the contact with the external environment may lead to microbial infection. Wound dressings are capable of providing a protective barrier and accelerate the wound healing process [1]. Chitosan is one of the most promising materials for wound dressings, due to its good biocompatibility, low toxicity, haemostatic properties, antibacterial activity and biodegradability [2]. The main goal of this work is to produce chitosan-based hydrogels to be used as efficient and safe drug delivery platforms. Materials and methods Two different chitosan-based materials were produced starting from Bioceramed formulations, AbsorKi (suitable for absorbing exudate from the wound) and HemoKi (enhancing haemostasis). The latter was modified by the addition of genipin, a cross-linking agent. The dressings were individually loaded with two different drugs, polyhexamethylene biguanide (PHMB, also called polyhexanide) and chlorhexidine diacetate (CHX), by soaking in solutions containing each drug (24 h, 5 mL, 36 °C, 180 rpm, 0.5 mg/mL for PHMB and 5 mg/mL for CHX). The physical properties (swelling, tensile strength) of the materials were studied prior and upon sterilisation by high hydrostatic pressure (HHP, 600 MPa, 10 min, 70 °C). Surface morphology was analysed by scanning electron microscopy (SEM). In vitro drug release studies were performed with a Franz diffusion cell system, combined with UV–Vis absorption spectroscopy for drug quantification. The efficiency of HHP was evaluated by sterility tests. Chorioallantoic membrane (HET-CAM) tests were done to study potential irritation of the skin. Results Both dressings present a porous structure and an extremely high swelling capacity (>1700%) before sterilisation. HPP affected the materials in different ways: it increased the swelling capacity of AbsorKi but decreased it for HemoKi. The drug release profiles indicated that the concentrations of PHMB and CHX increased in a sustained way on the first day. HHP increases the amount of drug released, except for AbsorKi with PHMB. Regarding the mechanical properties, sterilisation improved the resistance of both dressings. HET-CAM tests suggest that the produced materials do not lead to irritation. Discussion and conclusions HHP revealed an efficient method to ensure the materials sterilisation making the drug loaded wound dressings potentially efficient devices for the absorption of exudate from the wound bed. The combination of chitosan, a natural antibacterial agent, with the studied disinfectant and antiseptic drugs may lead to promising materials to be used as drug delivery platforms. Further studies in animal models are needed to conclude about the safety and clinical usefulness of the developed dressings.

Biocomposite Materials Based on Chitosan and Lignin: Preparation and Characterization

In this study, bioactive composite systems based on natural polymers (chitosan and lignin) were prepared in this study. The structural, mechanical, and morphological properties of chitosan-based materials containing various amounts of lignin filler were investigated. The infra-red IR spectroscopy data confirmed the formation of chemical bonds between the components of the obtained composites. The mechanical properties of film samples were studied in air and in physiological solution. It was demonstrated that the breaking elongation values of the obtained film samples in the wet state were higher (150–160%) than the corresponding (average) value of a pure chitosan film (100%). The scanning electron microscopy and atomic force microscopy data demonstrated that the introduction of lignin had caused significant changes in the surface morphology of films. The appearance of a strongly pronounced texture and porosity facilitated cell proliferation on the surface of composites, i.e., the bioactivity of film samples was enhanced with an increasing lignin content in the chitosan matrix.

Recent advances in microfluidic-aided chitosan-based multifunctional materials for biomedical applications

Chitosan-based biomaterials has shown great advantages in a broad range of applications, including drug delivery, clinical diagnosis, cell culture and tissue engineering. However, due to the lack of control over the fabrication processes by conventional techniques, the wide application of chitosan-based biomaterials has been hampered. Recently, microfluidics has been demonstrated as one of the most promising platforms to fabricate high-performance chitosan-based multifunctional materials with monodisperse size distribution and accurately controlled morphology and microstructures, which show great promising for biomedical applications. Here, we review recent progress of the fabrication of chitosan-based biomaterials with different structures and integrated functions by microfluidic technology. A comprehensive and in-depth depiction of critical microfluidic formation mechanism and process of various chitosan-based materials are first interpreted, with particular descriptions about the microfluidic-mediated control over the morphology and microstructures. Afterwards, recently emerging representative applications of chitosan-based multifunctional materials in various fields, are systematically summarized. Finally, the conclusions and perspectives on further advancing the microfluidic-aided chitosan-based multifunctional materials toward potential and versatile development for fundamental researches and biomedicine are proposed.

Chitosan-Based Functional Materials for Skin Wound Repair: Mechanisms and Applications.

Skin wounds not only cause physical pain for patients but also are an economic burden for society. It is necessary to seek out an efficient approach to promote skin repair. Hydrogels are considered effective wound dressings. They possess many unique properties like biocompatibility, biodegradability, high water uptake and retention etc., so that they are promising candidate materials for wound healing. Chitosan is a polymeric biomaterial obtained by the deacetylation of chitin. With the properties of easy acquisition, antibacterial and hemostatic activity, and the ability to promote skin regeneration, hydrogel-like functional wound dressings (represented by chitosan and its derivatives) have received extensive attentions for their effectiveness and mechanisms in promoting skin wound repair. In this review, we extensively discussed the mechanisms with which chitosan-based functional materials promote hemostasis, anti-inflammation, proliferation of granulation in wound repair. We also provided the latest information about the applications of such materials in wound treatment. In addition, we summarized the methods to enhance the advantages and maintain the intrinsic nature of chitosan via incorporating other chemical components, active biomolecules and other substances into the hydrogels.

Porosity Pattern of 3D Chitosan/Bioactive Glass Tissue Engineering Scaffolds Prepared for Bone Regeneration

Aim: The study was conducted to investigate the obtained external and internal porosity and the pore-interconnectivity of specific fabricated bioactive composite tissue engineering scaffolds for bone regeneration in dental applications. Materials and Methods: In this study, the bioactive glass [M] was elaborated as a quaternary system to be incorporated into the chitosan [C] scaffold preparation on a magnetic stirrer to provide bioactivity and better strength properties for the attempted composite scaffolds [C/ M] of variable compositions. The homogenous chitosan/bioactive glass mix was poured into tailor-made cylindrical molds [10cm×10cm]; a freeze-dryer program was used for the creation of uniform and interconnected macropores for all prepared chitosan-based scaffolds. The morphology of fabricated chitosan [C] and chitosan-bioactive glass [C/ M] composite scaffolds was studied by a scanning electron microscope [SEM] and a mercury porosimeter. In addition, the in-vitro biodegradation rate of all elaborated scaffolds was reported after immersing the prepared scaffolds in a simulated body fluid [SBF] solution. Furthermore, for every prepared scaffold composition, characterization was performed for phase identification, microstructure, porosity, bioactivity, and mechanical properties using an X-ray diffraction analysis [XRD], an X-ray Fourier transfer infrared spectroscopy [FTIR], a mercury porosimetry, a scanning electron microscopy [SEM] coupled to an energy-dispersive X-ray spectrometry [EDS] and a universal testing machine, respectively. Results: All the prepared porous chitosan-based composite materials showed pore sizes suitable for osteoblasts seeding, with relatively larger pore sizes for the C scaffolds. Conclusion: The smart blending of the prepared bioactive glass [M] with the chitosan matrix offered some advantages, such as the formation of an apatite layer for cell adhesion upon the scaffold surfaces, the reasonable decrease in scaffold pore size, and the relative increase in compressive strength that were enhanced by the incorporation of [M]. Therefore, the morphology, microstructure, and mechanical behavior of the elaborated stress loaded biocomposite tissue engineering scaffolds seem highly dependent on their critical contented bioactive glass.

Advances in Research of Chitosan-based Composites for Implanted Medical Devices

It is well known that chitosan-based composites are widely used in implantable medical devices. The development of chitosan-based composite materials with different types was summarized in this paper, such as inorganic, organic and composite phases. Then, combined with the research focus, the development of 3D printing technology and chitosan-based composites was summarized. It was also pointed out that the existing problems in our research, which need to be solved urgently. At last, the development direction and broad application prospect of chitosan-based composites were prospected. And we look forward to providing reference for relevant research.

Recent Developments in Chitosan-Based Adsorbents for the Removal of Pollutants from Aqueous Environments.

The quality of water is continuously under threat as increasing concentrations of pollutants escape into the aquatic environment. However, these issues can be alleviated by adsorbing pollutants onto adsorbents. Chitosan and its composites are attracting considerable interest as environmentally acceptable adsorbents and have the potential to remove many of these contaminants. In this review the development of chitosan-based adsorbents is described and discussed. Following a short introduction to the extraction of chitin from seafood wastes, followed by its conversion to chitosan, the properties of chitosan are described. Then, the emerging chitosan/carbon-based materials, including magnetic chitosan and chitosan combined with graphene oxide, carbon nanotubes, biochar, and activated carbon and also chitosan-silica composites are introduced. The applications of these materials in the removal of various heavy metal ions, including Cr(VI), Pb(II), Cd(II), Cu(II), and different cationic and anionic dyes, phenol and other organic molecules, such as antibiotics, are reviewed, compared and discussed. Adsorption isotherms and adsorption kinetics are then highlighted and followed by details on the mechanisms of adsorption and the role of the chitosan and the carbon or silica supports. Based on the reviewed papers, it is clear, that while some challenges remain, chitosan-based materials are emerging as promising adsorbents.

Influence of strain rate on the mechanical behavior of dry and hydrated chitosan-based dense materials for bioabsorbable implant applications

Chitosan has generated enormous interest in the scientific community because of its distinctive biological and physicochemical properties, which allow new advanced structures and applications. Porous chitosan scaffolds have been extensively studied and explored in bone generation, however it is still a challenge to obtain bioabsorbable orthopedic implants that involves pure 3D dense chitosan geometries due to the inherent difficulties in producing and shaping such structures.In this work, chitosan was blended with 10% glycerol and 10% glycerol + 10% biphasic mixture of calcium phosphate (70% hydroxyapatite with 30% β-tricalcium phosphate) to produce dense chitosan-based blocks, which were then shaped into rods. The introduction of plasticizer aimed to improve the materials ductility while the ceramic particles were used to increase stiffness and strength. The mechanical behavior of the two chitosan-based compositions was evaluated by uniaxial compression tests using a customized split-Hopkinson pressure bar (SHPB). The specimens were analysed in quasi-static conditions (less than 0.1 s−1) and medium strain rate conditions (200–800 s−1), both in dry state and in different hydrated conditions, in the latter case to approximate the in vivo implant conditions.The results showed promising results for the intended application. The chitosan blends present excellent ductility with an elastic perfect-plastic behavior in quasi-static conditions, with yield stresses around 40 MPa for the dry state, with a decay for 3 MPa after 48h hydration. An empirical model was proposed to describe the flow stress curves, with a good agreement with the experimental data, allowing future modelling of this material behavior.

Recent advances in using of chitosan-based adsorbents for removal of pharmaceutical contaminants: A review

During recent years, the pharmaceutical compounds have been considered as an emerging water micro-pollutant, due to their potential eco-toxicity. Among the various treatment approaches, the adsorption method has been found an attractive, simple and powerful tool for the removal of these compounds. Recently, the chitosan-based materials (composite), as an eco-friendly biopolymers class, show remarkable promise for effective adsorption of these compounds. This paper aims to establish criteria for choosing the finest chitosan-derivatives through a critical review and assess the published researches dealing with the effectiveness of them in the adsorptive removal of pharmaceutical compounds. This is followed by a preliminary summary for pharmaceutical contaminants adsorption performance of studied chitosan-based materials in tables. In this review article, the pharmaceutical materials also introduced into three categories as antibiotics (tetracycline, amoxicillin, etc.), non-steroidal anti-inflammatory (diclofenac, ibuprofen, etc.) and other pharmaceutical compounds (hydroquinone, fluoxetine, etc.), and the employed adsorbents for their removal were studied. This review provides information for the development of composite adsorbents, enhancement of adsorption ability by modification with different functional groups, real wastewater treatment, multicomponent adsorption, regeneration enhancement and fixed-bed studies which is helpful for readers to water and wastewater treatment process at both laboratory and field scales. Along this line, the impact of the various parameters (pH, sorbent amount, initial concentration, temperature, etc.) and the adsorption mechanism are also briefly discussed. • Pharmaceutical compounds have been considered as an emerging water micro-pollutants. • Chitosan-based materials are promising as drug adsorbents in removal investigations. • pH, temperature and ionic strength were found as the most effective parameters.

Characterization of Chitosan-Based Scaffolds Seeded with Sheep Nasal Chondrocytes for Cartilage Tissue Engineering.

The treatment of cartilage defect remains a challenging issue in clinical practice. Chitosan-based materials have been recognized as a suitable microenvironment for chondrocyte adhesion, proliferation and differentiation forming articular cartilage. The use of nasal chondrocytes to culture articular cartilage on an appropriate scaffold emerged as a promising novel strategy for cartilage regeneration. Beside excellent properties, chitosan lacks in biological activity, such as RGD-sequences. In this work, we have prepared pure and protein-modified chitosan scaffolds of different deacetylation degree and molecular weight as platforms for the culture of sheep nasal chondrocytes. Fibronectin (FN) was chosen as an adhesive protein for the improvement of chitosan bioactivity. Prepared scaffolds were characterised in terms of microstructure, physical and biodegradation properties, while FN interactions with different chitosans were investigated through adsorption-desorption studies. The results indicated faster enzymatic degradation of chitosan scaffolds with lower deacetylation degree, while better FN interactions with material were achieved on chitosan with higher number of amine groups. Histological and immunohistochemical analysis of in vitro engineered cartilage grafts showed presence of hyaline cartilage produced by nasal chondrocytes.

Influence of plasticiser type and nanoclay on the properties of chitosan-based materials

Chitosan, a biocompatible polysaccharide having antimicrobial efficacy, is highly useful for biomedical and other applications. How chitosan properties can be tailored continues to attract intense research interest. Herein, chitosan and chitosan/carboxymethyl cellulose (CMC) materials filled with montmorillonite (MMT) were thermomechanically processed resulting in excellent nanoclay dispersion. Inclusion of MMT significantly increased molecular relaxation temperatures, tensile mechanical properties, and film surface hydrophobicity. When plasticisers such as 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) or glycerol were introduced, the effect of MMT on the biopolymer properties largely depends on whether the MMT alters plasticiser–biopolymer interactions. [C2mim][OAc]-plasticised chitosan exhibited a relatively high contact angle (100 ± 7°) similar to the un-plasticised chitosan/MMT material, derived from the strong hydrogen-bonding capability of [C2mim][OAc]. Polyelectrolyte complexation (PEC) allowed the glycerol-plasticised chitosan/CMC material to have a hydrophobic surface (contact angle: 90 ± 6°) similar to that of the un-plasticised chitosan/CMC/MMT material. Specifically, further inclusion of MMT interrupted biopolymer–plasticiser interactions, leading to increased surface wettability. However, while addition of [C2mim][OAc] resulted in reduced hydrophilicity of the chitosan/CMC matrix, addition of MMT counteracted this effect by interacting with the IL. This work shows the plasticisers and MMT influence surface hydrophilicity mainly by determining the availability of free biopolymer polar groups.

Chitosan-based smart hybrid materials: a physico-chemical perspective.

Chitosan is one of the most studied cationic polysaccharides. Due to its unique characteristics of being water soluble, biocompatible, biodegradable, and non-toxic, this macromolecule is highly attractive for a broad range of applications. In addition, its complex behavior and the number of ways it interacts with different components in a system result in an astonishing variety of chitosan-based materials. Herein, we present recent advances in the field of chitosan-based materials from a physico-chemical perspective, with focus on aqueous mixtures with oppositely charged colloids, chitosan-based thin films, and nanocomposite systems. In this review, we focus our attention on the physico-chemical properties of chitosan-based materials, including solubility, mechanical resistance, barrier properties, and thermal behaviour, and provide a link to the chemical peculiarities of chitosan, such as its intrinsic low solubility, high rigidity, large charge separation, and strong tendency to form intra- and inter-molecular hydrogen bonds.