A review on versatile applications of biomaterial/polycationic chitosan: An insight into the structure-property relationship

Global trends and perspectives in nanochitin research: A comprehensive review of types, properties, applications, and scientometric analysis

This review presents a detailed exploration of global trends and prospects in nanochitin research, focusing on its types, properties, applications, and scientometric analysis. Nanochitin, a nanoscale derivative of chitin, has gained significant interest due to its unique properties, such as mechanical strength, biocompatibility, and biodegradability. This paper explores various forms of nanochitin, including chitin nanocrystals (ChNCs)/chitin nanowhiskers (ChNWs) and chitin nanofibers (ChNFs), and their broad applicability across sectors such as food, electronics, agriculture, biomedicine, environment, and cosmetics. In food applications, nanochitin enhances preservation, acts as a functional additive, and promotes gut health. In electronics, its potential in flexible, biodegradable electronics is explored, while in agriculture, it functions as a growth promoter, antitranspirant, and pesticide. Biomedical applications include tissue engineering, wound healing, and drug delivery. The paper also explores its environmental uses in water purification and pollution control. In cosmetics, nanochitin offers biocompatibility, antibacterial, anti-inflammatory, moisturizing, and anti-aging properties, with recent advances highlighting its role as both a bioactive ingredient and delivery system in skincare. Additionally, the review incorporates scientometric analysis to identify key trends, influential contributors, and research gaps. The analysis reveals exponential publication growth since 1992, with China and Japan leading contributions and emerging hotspots in food packaging and Pickering emulsions. The prospects of nanochitin in advancing sustainable technologies and addressing global challenges are discussed, emphasizing the need for interdisciplinary research and development. This review aims to provide a foundational resource for researchers, guiding future innovations in nanochitin applications and commercialization.

Solid-state tailored silver nanocomposites from chitosan: Synthesis, antimicrobial evaluation and molecular docking

This study thoroughly explores the synthesis, characterization, and antimicrobial efficacy of three α-aminophosphonate-chitosan (α-AP-Cs) compounds and their nano‑silver functionalized organic hybrids. α-AP-Cs derivatives (CU, CT and CSC) were synthesized via an in-situ, one-pot reaction using chitosan and triphenyl-phosphite, with different carbamide-glutaraldehyde crosslinkers; urea-glutaraldehyde, thiourea-glutaraldehyde and semicarbazide-glutaraldehyde, respectively. Subsequently, their corresponding α-AP-Cs‑silver nanocomposites (CU-Ag0NPs, CT-Ag0NPs and CSC-Ag0NPs) were synthesized via solid-state approach. Their physicochemical and morphological profiles were fully characterized and compared against chitosan-Ag0NPs (Cs-Ag0NPs) and their bare organic-cores via CHNS/P/O, FT-IR, XRD, TEM, EDX, XPS and UV-visible analysis. The synthesis procedure, including phosphonation and carbamide-glutaraldehyde crosslinking, was confirmed through spectroscopic and elemental analyses. XPS and XRD affirmed the metallic silver with FCC structure. The UV-visible absorption peak was ⁓399 nm with averaging TEM size of the semi-spherical Ag0NPs around 30.4 nm. Thereafter, antimicrobial properties were systematically explored and optimized by evaluating minimum inhibition concentration, dose-killing, growth kinetics curves, protein leakage, and antibiofilm activity against bacterial strains (Streptococcus mutans and Pseudomonas aeruginosa) and fungal strains (Candida albicans and Rhizopus oryzae). Notably, incorporating α-aminophosphonate and Ag0NPs into chitosan-backbone markedly enhanced its antimicrobial efficacy against bacterial and fungal biofilms. Finally, a detailed structure-activity relationship study was conducted to elucidate the antimicrobial mechanisms.

High-pressure CO2 treatment of cellulose, chitin and chitosan: A mini review and perspective

High-pressure CO2 (HPCD) technology has emerged as an environmentally sustainable approach for processing natural polymers such as cellulose, chitin, and chitosan. These polymers, valued for their abundance, biodegradability, and renewability compared to petroleum-based materials, provide a promising foundation for green technologies when combined with HPCD. In this mini review, we begin with an overview of the sources and structures of cellulose, chitin, and chitosan, followed by a discussion of the principles of HPCD and its functionality and role in treating these natural polymers. We then review representative examples of HPCD-treated cellulose, chitin, and chitosan, highlighting various applications, including those in biomedical engineering, environmental remediation, and other fields. Finally, we address current challenges, unresolved issues, and offer perspectives on the future opportunities for HPCD-treated cellulose, chitin, chitosan, and their relevant natural resources.

Multifunctional Chitosan-Covalent Bonded Multi-Walled Carbon Nanotubes Composite Binder for Enhanced Electrochemical Performances of Lithium-Sulfur Batteries

Lithium-sulfur batteries (LSBs) are considered as one of the most promising next-generation energy-storage devices because of their high energy density. However, the long-term use of LSBs is mainly limited by polysulfide shuttling and cathode structural degradation caused by volume changes during charging and discharging. To address these issues, a multifunctional, high-performance aqueous binder is developed by modifying a natural polysaccharide with multi-walled carbon nanotubes (MWCNTs). Specifically, the catechol-conjugated chitosan (CCS) acts as the binder, showing strong polysulfide adsorption, while the MWCNTs covalently bonded to CCS enhance the mechanical toughness and electronic conductivity. The resulting CCS-MWCNTs composite binder exhibits a tensile strength of 40 MPa and a strain at break of 300%, which are higher than those of CCS. As a binder for sulfur cathodes, the CCS-MWCNTs binder demonstrates superior cyclic stability and rate capability. At a sulfur loading of 2.0 mg cm⁻2, it delivers an initial capacity of 1016 mAh g⁻¹ at 0.2 C and retains 690 mAh g⁻¹ after 100 cycles, significantly outperforming commercial polyvinylidene difluoride (PVDF), sodium carboxymethylcellulose/styrene butadiene rubber (CMC/SBR), and CCS binders. This study demonstrates the potential applications of polysaccharide binders in metal-sulfur batteries by innovatively incorporating carbon nanotubes into the biopolymer binder, providing a promising alternative for environmentally friendly energy storage.

Peripheral nerve regeneration with 3D printed bionic double-network conductive scaffold based on GelMA/chitosan/polypyrrole

Peripheral nerve injury (PNI) is a serious condition with limited surgical treatment options available. Conductive hydrogels have emerged as a promising alternative due to their ability to facilitate electrical signal exchange between cells and replicate the physiological microenvironment of electroactive tissues. Three-dimensional (3D) printing offers an innovative approach for fabricating neural scaffolds with precise structures and complex spatial architectures. In this study, we introduce a novel dual-bioink 3D printing strategy that integrates synthetic and natural materials to construct stable biomimetic neural tissue structures. The base bioink, comprising gelatin methacrylate (GelMA), chitosan (CS), and the conductive polymer polypyrrole (PPy), serves as a physical support network. It offers conductive pathways, promote cell growth, and ensures long-term structural integrity. The secondary bioink is a cell-loaded biodegradable gel-gelatin, which enables for precise cell deposition within the base network through a hybrid printing technique. The composite scaffold was evaluated for its mechanical properties, cytotoxicity, and ability to support neural differentiation. The results demonstrated that the 3D-printed neural network scaffold effectively promoted the neural differentiation and axon regeneration of PC-12 cells and HT-22 cells. These findings highlight its strong potential for facilitating neural functional recovery, positioning it as a promising candidate material for the treatment of PNI patients.

Natural-Synthetic Hybrid Nanostructures Formed Through the Interaction of Chitosan with Carboxylate-Ended PNIPAM: Structure and Curcumin Encapsulation

Chitosan is widely used in drug delivery applications, due to its biocompatibility, bio-degradability, and low toxicity. Nevertheless, its properties can be enhanced through the physical or chemical modification of its amino and hydroxyl groups. This work explores the electrostatic complexation of two chitosan samples of differing lengths with two poly(N-isopropylacrylamide) (PNIPAM) homopolymers of different molecular weight carrying a chargeable carboxyl end group. This interaction enables the electrostatic binding of PNIPAM side chains onto the chitosan backbone through the amino groups, and could be considered as an alternative grafting method. Dynamic and electrophoretic light scattering techniques were employed in order to study the solution/dispersion properties of the formed complexes as a function of the PNIPAM concentration, or, equivalently, the molar/charge ratio of the two components. The obtained results revealed that their mass, size, and charge mostly depend on the length of the two individual constituents, as well as their mixing ratio. Furthermore, their response to changes in their environment, namely temperature and ionic strength, was also examined, demonstrating the effect of either the thermoresponsiveness of PNIPAM or the electrostatic charge screening, respectively. Fluorescence spectroscopy, utilizing pyrene as a probe, provided information regarding the hydrophobicity of the formed complexes, while images from scanning transmission electron and atomic force microscopies further elucidated their morphology, which was found to be closely related to that of the corresponding chitosan molecule. Finally, their potential as drug delivery vehicles was also investigated, utilizing curcumin as a model drug at various loading concentrations.

Recent advances in modifications, biotechnology, and biomedical applications of chitosan-based materials: A review

Chitosan, a natural polysaccharide with recognized biocompatibility, non-toxicity, and cost-effectiveness, is primarily sourced from crustacean exoskeletons. Its inherent limitations such as poor water solubility, low thermal stability, and inadequate mechanical strength have hindered its widespread application. However, through modifications, chitosan can exhibit enhanced properties such as water solubility, antibacterial and antioxidant activities, adsorption capacity, and film-forming ability, opening up avenues for diverse applications. Despite these advancements, realizing the full potential of modified chitosan remains a challenge across various fields. The purpose of this review article is to conduct a comprehensive evaluation of the chemical modification techniques of chitosan and their applications in biotechnology and biomedical fields. It aims to overcome the inherent limitations of chitosan, such as low water solubility, poor thermal stability, and inadequate mechanical strength, thereby expanding its application potential across various domains. This review is structured into two main sections. The first part delves into the latest chemical modification techniques for chitosan derivatives, encompassing quaternization, Schiff base formation, acylation, carboxylation, and alkylation reactions. The second part provides an overview of the applications of chitosan and its derivatives in biotechnology and biomedicine, spanning areas such as wastewater treatment, the textile and food industries, agriculture, antibacterial and antiviral activities, drug delivery systems, wound dressings, dental materials, and tissue engineering. Additionally, the review discusses the challenges associated with these modifications and offers insights into potential future developments in chitosan-based materials. This review is anticipated to offer theoretical insights and practical guidance to scientists engaged in biotechnology and biomedical research.

Progress in chitin/chitosan and their derivatives for biomedical applications: Where we stand

Chitin and its deacetylated form, chitosan, have demonstrated remarkable versatility in the realm of biomaterials. Their exceptional biocompatibility, antibacterial properties, pro- and anticoagulant characteristics, robust antioxidant capacity, and anti-inflammatory potential make them highly sought-after in various applications. This review delves into the mechanisms underlying chitin/chitosan's biological activity and provides a comprehensive overview of their derivatives in fields such as tissue engineering, hemostasis, wound healing, drug delivery, and hemoperfusion. However, despite the wealth of studies on chitin/chitosan, there exists a notable trend of homogeneity in research, which could hinder the comprehensive development of these biomaterials. This review, taking a clinician's perspective, identifies current research gaps and medical challenges yet to be addressed, aiming to pave the way for a more sustainable future in chitin/chitosan research and application.

Bio-Based and Biodegradable Polymeric Materials for a Circular Economy

Nowadays, plastic contamination worldwide is a concerning reality that can be addressed with appropriate society education as well as looking for innovative polymeric alternatives based on the reuse of waste and recycling with a circular economy point of view, thus taking into consideration that a future world without plastic is quite impossible to conceive. In this regard, in this review, we focus on sustainable polymeric materials, biodegradable and bio-based polymers, additives, and micro/nanoparticles to be used to obtain new environmentally friendly polymeric-based materials. Although biodegradable polymers possess poorer overall properties than traditional ones, they have gained a huge interest in many industrial sectors due to their inherent biodegradability in natural environments. Therefore, several strategies have been proposed to improve their properties and extend their industrial applications. Blending strategies, as well as the development of composites and nanocomposites, have shown promising perspectives for improving their performances, emphasizing biopolymeric blend formulations and bio-based micro and nanoparticles to produce fully sustainable polymeric-based materials. The Review also summarizes recent developments in polymeric blends, composites, and nanocomposite plasticization, with a particular focus on naturally derived plasticizers and their chemical modifications to increase their compatibility with the polymeric matrices. The current state of the art of the most important bio-based and biodegradable polymers is also reviewed, mainly focusing on their synthesis and processing methods scalable to the industrial sector, such as melt and solution blending approaches like melt-extrusion, injection molding, film forming as well as solution electrospinning, among others, without neglecting their degradation processes.

A multifunctional gingival retraction cord with antibacterial and hemostasis properties based on Chitosan/Propolis/Tranexamic acid for dental treatment

A novel gingival retraction cord named P/TA@CSy was prepared using chitosan yarns (CSy) loaded with tranexamic acid (TA) and Propolis (P). P/TA@CSy has good toughness with a breaking strength of 41.3 Pa, benefiting from the twisting structure and Propolis coating. A short coagulation time of 456 s was achieved for P/TA@CSy because of the potent blood absorption ability from the effective attachment of tranexamic acid. Moreover, excellent antibacterial ability was obtained with the antibacterial rates against E. coli of 94.73 %, S. aureus of 99.99 % and S. mutans of 99.99 %, contributing to Propolis's antibacterial ability. In addition, suppression of the expression of pro-inflammatory cytokines (IL-6 and TNF-α) was found, which could prevent wound infection. P/TA@CSy displayed excellent cytocompatibility with the cell activity of 100 % after 24 h. Therefore, P/TA@CSy could rapidly respond to gingival hemostasis and infection prevention, showing excellent potential in dental treatment.

Chitosan-ricobendazole complex: Synthesis, characterization and anthelmintic activity

Synthesis, characterization and assessment of therapeutic efficacy of chitosan-ricobendazole complex were carried out for the first time in this work. Study of physico-chemical properties revealed the optimal ratio of chitosan: ricobendazole (30:4). Quantum chemical modeling set the optimal parameters for the formation of the chitosan-ricobendazole molecular system (E = -3765.26 kcal/mol, η = 0.127 eV), which was confirmed by Fourier-transform infrared spectroscopy. Scanning electron microscopy showed spherical particles of chitosan-ricobendazole complex ranging in size from 100 to 200 μm. Study of therapeutic efficiency was conducted on sheep with dicroceliosis. Notably, the therapeutic efficiency of the chitosan-ricobendazole complex (4 mg/kg of ricobendazole) reached 89 %, while the therapeutic efficiency of the commercial preparation ricazole (8 mg/kg of ricobendazole) was 92 %. Biochemical blood test indicated equivalent normalization of hematological parameters in sheep after treatment with ricazole and the chitosan-ricobendazole complex. Histological examination of infected sheep liver revealed that treatment with the chitosan-ricobendazole complex leads to a decrease in the number of helminth eggs with subsequent therapeutic effect on the severity of the disease. This proves the enhanced solubility of ricobendazole at a dosage of 4 mg/kg, active interaction of the components and relatively high bioavailability without increasing the release rate of ricobendazole.

An insect lac blanket-mimetic and degradable shellac hydrogel/chitosan packaging film with controllable gas permeation for fresh-cut vegetables preservation

Fresh-cut products are extremely perishable due to the processing operations, and the atmosphere environment, especially CO2, O2 and H2O, could profoundly affect their shelf life. Herein, an insect "lac blanket"-mimetic and facile strategy was proposed for fresh-cut vegetables preservation, employing porous shellac hydrogel microparticles as gas "switches" in chitosan film to regulate CO2, O2 and H2O vapor permeability. Thus, the shellac hydrogel/chitosan hybrid film presented the controllable and wide range of gas permeability, compared with the chitosan film. The shellac-COOH nanoscale vesicles aggregated to form shellac hydrogel network via hydrophobic binding. The shellac hydrogel microparticles played a certain lubricating effect on the hybrid film casting solution. The hydrogen bond network between shellac hydrogel and chitosan contributed to the excellent mechanical properties of the hybrid film. The hybrid film also exhibited remarkable water-resistant, antifogging properties, optical transparency and degradability. The hybrid packaging films prepared through this strategy could adjust the internal gas (CO2, O2, H2O and ethylene) contents within the packages, and further exhibited admirable preservation performance on three fresh-cut vegetables with different respiratory metabolisms. This gas permeation-controlled strategy has great potential in fresh food preservation and various other applications that need a modified atmosphere.

Natural Antimicrobials in Dairy Products: Benefits, Challenges, and Future Trends

This review delves into using natural antimicrobials in the dairy industry and examines various sources of these compounds, including microbial, plant, and animal sources. It discusses the mechanisms by which they inhibit microbial growth, for example, by binding to the cell wall's precursor molecule of the target microorganism, consequently inhibiting its biosynthesis, and interfering in the molecule transport mechanism, leading to cell death. In general, they prove to be effective against the main pathogens and spoilage found in food, such as Escherichia coli, Staphylococcus aureus, Bacillus spp., Salmonella spp., mold, and yeast. Moreover, this review explores encapsulation technology as a promising approach for increasing the viability of natural antimicrobials against unfavorable conditions such as pH, temperature, and oxygen exposure. Finally, this review examines the benefits and challenges of using natural antimicrobials in dairy products. While natural antimicrobials offer several advantages, including improved safety, quality, and sensory properties of dairy products, it is crucial to be aware of the challenges associated with their use, such as potential allergenicity, regulatory requirements, and consumer perception. This review concludes by emphasizing the need for further research to identify and develop effective and safe natural antimicrobials for the dairy industry to ensure the quality and safety of dairy products for consumers.

Chitosan: Structural and Chemical Modification, Properties, and Application

Chitosan is a polymer of natural origins that possesses many favourable properties [...].