This review covers the latest issues related to the development of medical technologies based on chitosan coatings. The progress of modern implantology requires medicine to adapt constantly to new opportunities and challenges. Infections may occur at the implantation site or in the body and may require treatment with antibiotics or surgery to resolve them. Due to its unique properties, such as biocompatibility, biodegradability, non-toxicity and antibacterial activity, chitosan has been proposed to be co-deposited with biocidal silver nanoparticles in the form of nanocomposite coatings on the surface of metallic implants to extinguish local inflammations. The mechanism of co-deposition of chitosan with metal ions and particles using electrophoretic deposition has not yet been thoroughly explained. This, among others, results from a number of factors that influence the process and their mutual relations. Therefore, the present review aims at a deeper understanding of the mechanism of creating chitosan-silver nanocomposite coatings.

Chitosan and chitooligosaccharides, which are products of chitin modification, have wide industrial applications. An improved understanding of the structure and properties of chitin-modifying enzymes has increased the interest in obtaining them from microbial sources and using them in the biotechnological production of these essential sugars. Endophytic fungi include a diverse group of microorganisms that inhabit the intercellular and intracellular areas of plant tissues, thus exerting beneficial effects on host species. They are considered an extremely valuable source of biologically active secondary metabolites and enzymes with high application potential. This review presents the potential of endophytic fungi to produce chitin-modifying enzymes and discusses the role of chitin modification by enzymes produced by fungal endophytes in their survival in the plant host.

The review discusses the latest issues related to using chitosan, a biocompatible and biodegradable polymer derived from chitin, as a carrier in intelligent drug-delivery systems. The continuous development of medicine and rapid technological progress pose new challenges in designing new therapeutic agents. Chitosan has properties that make it suitable for drug-delivery applications, such as its ability to form nanoparticles and its mucoadhesion that enhance drug absorption. Chitosan can be combined with antibiotics, analgesics and other ingredients with specific properties. While chitosan is not medicinal substance, it can be a carrier in controlled drug-release systems.

The treatment of difficult-to-heal wounds is a major problem in modern medicine. The search for new materials and ways to treat wounds is important and timely. Insulin stimulates proliferation, differentiation and migration of skin fibroblasts and keratinocytes. Chitosan has beneficial biological properties and can be an effective carrier of insulin. This review discusses research into the development of chitosan formulations with insulin to aid local treatment of chronic wounds. The PubMed, Google Scholar, Scopus and Web of Science databases were searched for studies on chitosan preparations with insulin in terms of their efficacy in wound healing. Twelve original English-language articles published in peer-reviewed scientific journals were included in the analysis. Insulin preparations in a chitosan matrix in the form of gel, hydrogel, injection and non-woven dressing are highly effective at all stages of the wound-healing process. They show anti-inflammatory and antimicrobial effects. Insulin from the formulations is released in a prolonged or controlled manner. However, it seems necessary to learn more about the mechanisms of insulin action within lesions. Of note, the data are mainly from basic and preclinical studies. Only one clinical study has been conducted.

Cosmetics manufacturers are becoming increasingly interested in chitosan due to its interesting biological and technical properties, which include being a natural conditioning and moisturising agent for the skin and hair. Indeed, according to the European Commission database CosIng (https://ec.europa.eu/growth/tools-databases/cosing/details/ 75065), the functions assigned to chitosan in cosmetics are film forming and hair fixing. This review discusses the unique physicochemical and functional properties of chitosan, the market for chitosan-based skin care and hair products and recent advances. Finally, future perspectives regarding applications of this biopolymer in cosmetics are discussed.

This review provides a comprehensive summary of the results of research, published from 2002 to 2023, on the synthesis, physicochemical properties and medical applications of binary and ternary interpolyelectrolyte complexes (IPECs) based on chitosan, carboxymethylcellulose and collagen. The application of IPECs in the medical field mainly refers to their use in medical therapy and bone regeneration. In addition, we describe our original studies on IPECs based on chitosan and collagen.

The effect of chitosan oxidation with sodium periodate on the ability to form complexes with the dyes methylene blue, malachite green and acid fuchsin, which have an antiseptic effect, was investigated. A non-covalent interaction occurred for methylene blue and malachite green, while a covalent interaction occurred for acid fuchsin. Fourier-transform infrared spectroscopy confirmed the formation of chitosan composites with these dyes. The antimicrobial effect of these dyes complexed with oxidised chitosan against Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis and Escherichia coli was investigated. The non-covalent attachment of malachite green and methylene blue to chitosan preserved their antimicrobial effect; hence, complexes of these dyes with oxidised chitosan provide a more convenient form that is less staining. However, the covalent conjugation of acid fuchsin with oxidised chitosan caused a significant loss of the antimicrobial activity. The developed method of conjugation of specific dyes with chitosan can be used to create complexes of this biopolymer with a wide range of biologically active organic substances.

The aim of this work was to demonstrate the process of manufacturing and applying functionalising additives using a pilot research installation. As part of the optimisation evaluation, hygienic papers functionalised with biopolymer-biocide compositions based on chitosan, starch and Gemini surfactants were prepared. The microbiological properties and susceptibility to biodegradation of prototype hygienic papers (prepared in EPICOM) were assessed. In particular, the minimum amount of biopolymer and bioactive agent were determined to ensure the finished product exerted antibacterial activity against Staphylococcus aureus, Bacillus subtilis and Escherichia coli and was more than 90% biodegradable in a compost environment. Under optimal conditions, the hygienic paper exerted excellent antibacterial activity against S. aureus and E. coli as well as good activity against B. subtilis. Moreover, the hygienic paper showed more than 90% biodegradability in compost conditions within 8 weeks.

Chitosan, a polysaccharide derived from chitin, has adsorption capacity, particularly towards heavy metal ions. The aim of this study was to produce chitosan spheres with and without CCP 90 activated carbon and then to evaluate their adsorption ability and kinetics using an aqueous copper(II) solution. The research was conducted using ultraviolet–visible spectrophotometry, examining the surface morphology of the obtained spheres after copper ion (Cu²⁺) adsorption, along with elemental analysis with an energy dispersive spectrometric probe. The results confirmed an increase in the adsorption of Cu²⁺ on chitosan spheres with CCP 90 activated carbon.

The application of the immobilisation method – which consists of immobilising modified sawdust in a carrier, a chitosan gel – enabled the development of a new sorbent. By combining waste products from chitin and sawdust, the properties of both adsorbents were utilised. This paper evaluated the adsorption efficiency of four dyes – Reactive Yellow 84, Reactive Black 8, Basic Violet 10 and Basic Green 4 – on four adsorbents – chitin flakes, chitosan flakes, chitosan beads and sawdust immobilised in chitosan beads. The latter adsorbent showed good adsorption properties for both anionic and cationic dyes. The experimental results showed a relationship between the amount of adsorbed and desorbed dye and the type of adsorbent. Chitin flakes showed the lowest adsorption capacity, regardless of the type of dye. The immobilisation of modified sawdust in chitosan had a particularly positive effect on the binding efficiency of cationic dyes.

A highly efficient micropropagation process can be achieved by using proper conditions for root initiation and growth of regenerated shoots. The efficiency of auxin and chitosan on in vitro rhizogenesis of the highbush blueberry (Vaccinium corymbosum L.) cv. Liberty was developed. After the multiplication stage, explants were transferred to Woody Plant Medium (WPM) supplemented with 0.1 mg dm⁻³ zeatin and 1.0 or 2.0 mg dm⁻³ of the auxin indole-3-butyric acid (IBA), or chitosan with a molecular weight of 800 kDa at a concentration of 20 or 40 ppm. Among the tested combinations, the maximum mean shoot and root length (6.28 and 1.73 cm, respectively) were recorded for WPM with 0.1 mg dm⁻³ zeatin and 2.0 mg dm⁻³ IBA. The higher chitosan concentration in the WPM medium increased the length of shoots and roots. The highest percentage (100%) of rooted plants was obtained on WPM with the addition of 0.1 mg dm⁻³ zeatin and 40 ppm chitosan. Moreover, leaves of the highbush blueberries from this medium were brighter (L* from 22% to 36%) and greener (a* -2.70 and -4.56, respectively) compared with the leaves of plants grown on WPM containing IBA.

This study aimed to investigate the potential mitigation of copper stress in tomato plants (Solanum pimpinellifolium L0566) through the addition of chitosan (CH) or nanosilver (nAg) to Murashige and Skoog (MS) medium under in vitro conditions. Various growth parameters; the proline, malondialdehyde (MDA), total polyphenol and mineral contents; and CIE L*a*b* colour parameters were evaluated. After the multiplication stage, the explants were transferred to MS medium (control); MS + 20 ppm chitosan with a molecular weight of 3.33 kDa (CH_3.33); MS + 6 mg l⁻¹ nAg; MS + 100 μM l⁻¹ copper sulfate (CuSO₄); MS+20 ppm CH_3.33+100 μM l⁻¹ CuSO₄; or MS + 6 mg l⁻¹ nAg + 100 μM l⁻¹ CuSO₄. The results indicated that while CuSO₄ or CuSO₄-nAg solutions inhibited growth traits, CH_3.33 stimulated growth, particularly shoot production, and plants treated with CH_3.33 exhibited better developed roots and a higher fresh mass. Additionally, CH_3.33 alleviated the negative effects of CuSO₄ on the proline, MDA and total polyphenol contents in tomato plants. Moreover, tomato explants exhibited greener leaves, while those treated with nAg and CuSO₄ showed decreased colour values. CH_3.33 or nAg positively influenced the mineral content of tomato leaves under heavy metal stress. This study underscores the complex interactions between growth medium components on tomato plant growth, physiology and the mineral content, highlighting the potential of chitosan in mitigating heavy metal stress in tomato plants.

In developed countries, gastro-oesophageal reflux is one of the most frequently diagnosed diseases. Although acid reflux is more well known, alkaline reflux is equally troublesome. In either of the two cases, the oesophageal mucosa is destroyed. The aim of this study was to analyse the possibility of eliminating the problem by using hydrogels containing dextran and chitosan to prevent irritation of the oesophageal mucosa. The addition of chitosan to all tested gels increased their dynamic viscosity, enabling better adhesion and, consequently, better protection of the mucous membrane. The addition of dextran reduced the pH of the tested gels, which allowed for the neutralisation of alkaline reflux. Based on the texture tests, chitosan and dextran increased work of adhesion.

Young children have an incompletely developed digestive tract and they are susceptible to numerous disorders due to the return of acid and alkaline content to the oesophagus. The aim of the study was to analyse the ability of hydrogels containing chitosan and polyvinyl alcohol to prevent irritation of the oesophageal mucosa in children. The addition of chitosan to the tested gels increased their pH, which could be useful to neutralise gastric reflux, and dynamic viscosity. The texture tests revealed that chitosan and polyvinyl alcohol significantly increased the work of adhesion work.

Bombyx mori chitosan nanoparticles (ChS NPs) were obtained and the kinetic aspects of their size distribution depending on the degree of nonequilibrium of the synthesis by ionotropic gelation using sodium tripolyphosphate (TPP) were studied. The size of ChS NPs was greatly influenced by the ChS concentration, which varied from 0.5 to 10 mg/ml. The size of the NPs increased from 100 to 300 nm when the ChS concentration increased from 0.5 to 10 mg/ml and while maintaining all other parameters of the reaction. An increase in the ChS to-TPP ratio corresponded to a lower cross-linking density and thus ensured slower kinetics for NP formation alongside the formation of large chitosan/TPP aggregates. There was an almost threefold increase in the particle size when the pH of the medium increased from 3.8 to 4.7; thus, the size of ChS NPs depends on the pH of the solution. There was a slight agglomeration of NPs from 363 to 642 nm with an increase in the NP synthesis time from 4 to 24 h. According to calculations, the maximum interaction energy is 50.4 and 69.4 kcal/mol for deprotonated TPP (P₃O₁₀⁵⁻); after adiabatic transfer of the proton, the value decreases to 32.9–33.5 kcal/mol. The maximum interaction energy is –12.8 kcal/mol for the initially protonated TPP (H₄P₃O₁₀⁻).

This study reports a stepwise formation method of a chitosan membrane cross-linked with o-phthalaldehyde and its use as a polymer matrix in a quasi-solid-state-electrolyte-based supercapacitor. The proposed method of cross-linking in chitosan solution and evaporation of the solvent yielded a homogeneous and durable chitosan-o-phthalaldehyde membrane, which, after dipping in an aqueous 2 M lithium sulfate solution, formed a quasi-solid-state-electrolyte (CS/OPAQSSE). The prepared CS/OPA-QSSE was then used in an electric double layer capacitor (EDLC) cell to study its electrochemical properties. The electrochemical performance of the EDLC cell was determined by using the electrochemical impedance spectroscopy, cyclic voltammetry and galvanostatic charging/discharging techniques. The results showed that the EDLC cell with the CS/OPA-QSSE is a fully functional and efficient device. The specific capacitance values calculated for the CS/OPA-QSSE EDLC (up to 115 F g⁻¹) always surpassed the reference cell based on a commercial glass fibre separator Therefore, the proposed chitosan modification can be considered as a future alternative to produce other polysaccharide-based materials for electrochemical use.

This study explored the effects of chitosan, a biodegradable and non-toxic natural polymer derived from chitin, on the yield and quality of raspberries. Various molecular weights (3.3–950 kDa) were assessed to determine the impact on raspberry plants and fruit development. These applications were made during key growth phases – the start of the vegetation period, during flowering and at the fruit-bearing stage – using a foliar method to ensure full coverage of both leaves and fruit without runoff. The results indicated that chitosan application influenced various parameters of fruit quality, including firmness, colour and antioxidant levels. Notably, chitosan with a molecular weight of 21 and 50 kDa significantly enhanced fruit yield and size compared with the control. Conversely, chitosan with a higher molecular weight (500 and 950 kDa) did not improve yield and appeared to induce stress in plants, although they did contribute to increased fruit firmness and potentially extended the shelf life due to their film-forming capabilities. The findings suggest that while chitosan can improve the yield and quality of raspberries, the effectiveness is highly dependent on its molecular weight. These results support the potential of chitosan as an alternative to traditional chemical treatments, promising a reduction in chemical inputs while sustaining or enhancing agricultural productivity and fruit quality.

This paper presents a preliminary characterisation of the local mechanical properties of thermosensitive chitosan systems using dynamic light scattering, an endeavour that has not yet been attempted. The tests included solutions of chitosan chloride with the addition of sodium glycerophosphate as well as those without a substance to support the gelation process. There was much better agreement between the data obtained from measurements on the microscopic and macroscopic scales for systems without the addition of glycerophosphate. In most cases, the addition of a pH-neutralising salt resulted in higher values of dynamic moduli than those obtained during microrheological measurements. Therefore, it seems to be possible to use dynamic light scattering to conduct microrheological studies of thermosensitive chitosan systems.

Chitosan and its derivatives are promising plant biostimulants with potentially broad applications in agriculture and horticulture. In this study, we determined the effect of the application method and dose of depolymerised chitosan on morphological characteristics and metabolite levels in Eucomis autumnalis, a medicinal and ornamental plant. Depolymerised chitosan (molecular weight ~154,500 g/mol, number average molecular weight ~22,800 g/mol and degree of deacetylation ~85%) was used at 50 and 100 mg/l by drenching plants or spraying. In general, depolymerised chitosan increased the length of plant leaves and roots, especially at the dose of 100 mg/l, and also increased the fresh weight of leaves, bulbs and roots, with a more potent effect found when depolymerised chitosan was applied as a foliar spray. In addition, spraying the plants with chitosan solution at 50 and 100 mg/l caused a significant increase in the total chlorophyll content, by 55.4% and 42.0%, respectively, and the total polyphenol content, by 77.7% and 59.0%, respectively, compared with the control. On the other hand, the biosynthesis of carotenoids was most favourably affected by the application of 100 mg/l depolymerised chitosan by drenching and 50 mg/l depolymerised chitosan by spraying. Foliar application of depolymerised chitosan led to an increase in leaf L-ascorbic acid content by an average of 36.4%, regardless of the dose. The results suggest that depolymerised chitosan applied as a foliar spray promoted the growth of E. autumnalis and contributed to increased biosynthesis of polyphenols, which may be a future means of obtaining metabolites in this species.

This paper presents the influence of pH on the activity and stability of an extracellular chitin deacetylase produced by Absidia orchidis. It showed the highest activity at pH 4.0 and was most stable at pH 9.5. In addition, there was pH deactivation that could be described by first-order irreversible kinetics. The pH deactivation rate constant changed linearly with pH in the range from 4.0 to 9.0.

Chitooligosaccharides (COS) have numerous biological activities, including antibacterial, antifungal, antiviral, anticancer and antioxidant. Unlike high-molecular-weight chitosan, COS have a number of advantages in large-scale commercial applications due to their water solubility and low viscosity. COS are used in the food, agricultural, medical and pharmaceutical industries. The present study demonstrated that intracellular, partially purified enzymes from Mucor circinelloides IBT-83 can hydrolyse chitosan and effectively catalyse the synthesis of a heterodimer composed of D-glucosamine and N-acetyl-D-glucosamine (carried out at a 2.5-fold molar excess of N-acetyl-D-glucosamine relative to D-glucosamine in an acetate buffer [pH 5.5] containing 20% ammonium sulfate). The obtained product was analysed using high-performance liquid chromatography.

The aim of this paper was to design, prepare and characterise chitosan (Ch) and cyclosporine A (CsA) mixed films deposited on a plasma-activated polyethylene terephthalate (PET) polymer surface to be used as a cover for implantable blood vessel stents. The PET polymer coated with Ch and CsA layers was immersed in simulated body fluid (SBF) to examine how the obtained layers can behave in the environment of human body fluids. Time-of-flight secondary ion mass spectrometry was employed to determine the chemical composition of the deposited films and to analyse the spatial distribution of molecules on the PET surface. The results showed the controlled release of CsA from the chitosan matrix. It can be concluded that the modification of the PET polymer with layers of chitosan and CsA has great application potential in the tissue engineering as a biocompatible stent of blood vessels with therapeutic properties.

This paper presents research related to the development of hydrogel polymer biocomposites (chitosan and alginate) with an analgesic medication (lidocaine hydrochloride). The pharmaceutical availability of lidocaine hydrochloride from the hydrogel preparations was evaluated for transdermal systems in accordance with the Polish Pharmacopoeia, XI Edition. The rheological tests showed that these preparations had the characteristics of non-Newtonian, pseudoplastic liquids, for which the viscosity decreases as the shear rate increases. The developed hydrogel preparations showed bacteriostatic and bactericidal effects against both Escherichia coli and Staphylococcus aureus. The release of lidocaine hydrochloride from the tested hydrogel was a complex process that followed first-order kinetics. The rate of release could be influenced by appropriate selection of the composition of the biocomposite.

The potential of biodegradable and environmentally friendly substances that exhibit biostimulatory effects on plant growth and yield is now being exploited in horticultural production. This study evaluated the effect of chitosan on the growth, flowering, and yield of bulb of oriental lily ‘Mona Lisa’. Three types of chitosan differing in molecular weight (MW) were used: commercial chitosan (CCh, MW = 50,000–190,000 g/mol) and two forms of depolymerised chitosan (DCh 48, with a MW of ~48,000 g/mol, and DCh 154, with a MW of ~154,500 g/mol). The plants were watered twice with an aqueous solution of chitosan at a concentration of 2 g/l, with 100 ml of solution per pot. The control was plants watered with distilled water. Chitosan had a biostimulatory effect on the growth of lily plants. CCh increased the relative chlorophyll content of leaves (+11.3%), the fresh bulb weight (+11.0%), the bulb diameter (+12.3%) and the number of bulblets (+44.9%) compared with the control plants. DCh 154 significantly increased the fresh aboveground weight of plants (+31.3%), the fresh weight of leaves (+29.0%) and their number (+16.8%), the fresh weight of bulb (+12.3%) and their diameter (+11.0%), and the fresh weight of bulblet (+21.9%). DCh 48 increased the bulb diameter (+12.1%) and the number of bulblets (+45.4%), but decreased the length (-8.6%) and width of tepals (-6.8%) of the lily flowers. Finally, DCh 154 was the most effective in lily production. Using depolymerised chitosan as a biostimulant may contribute to developing new methods to produce high-quality lily plants.