Study of chitosan with different degrees of acetylation as cardboard paper coating

Chitosan Hemostatic Dressings: Properties and Surgical Applications

Wounds caused by trauma and/or surgery represent a significant challenge in contemporary medical practice, requiring innovative approaches to promote optimal healing and reduce the risk of bleeding and complications resulting from it. In this context, chitosan, a natural polysaccharide derived from chitin, represents an ideal material for the study and application of medical devices, in the form of dressings, in wound management for pre- and/or post-operative wounds due to its ability to induce hemostasis and its high biocompatibility with biological tissues. The aim of this work was to discuss the structural characteristics, properties and application of chitosan-based hemostatic dressings in hemostatic processes resulting from pre- or post-surgical approaches.

Exploring the diverse applications of Carbohydrate macromolecules in food, pharmaceutical, and environmental technologies

Carbohydrates are a class of macromolecules that has significant potential across several domains, including the organisation of genetic material, provision of structural support, and facilitation of defence mechanisms against invasion. Their molecular diversity enables a vast array of essential functions, such as energy storage, immunological signalling, and the modification of food texture and consistency. Due to their rheological characteristics, solubility, sweetness, hygroscopicity, ability to prevent crystallization, flavour encapsulation, and coating capabilities, carbohydrates are useful in food products. Carbohydrates hold potential for the future of therapeutic development due to their important role in sustained drug release, drug targeting, immune antigens, and adjuvants. Bio-based packaging provides an emerging phase of materials that offer biodegradability and biocompatibility, serving as a substitute for traditional non-biodegradable polymers used as coatings on paper. Blending polyhydroxyalkanoates (PHA) with carbohydrate biopolymers, such as starch, cellulose, polylactic acid, etc., reduces the undesirable qualities of PHA, such as crystallinity and brittleness, and enhances the PHA's properties in addition to minimizing manufacturing costs. Carbohydrate-based biopolymeric nanoparticles are a viable and cost-effective way to boost agricultural yields, which is crucial for the increasing global population. The use of biopolymeric nanoparticles derived from carbohydrates is a potential and economically viable approach to enhance the quality and quantity of agricultural harvests, which is of utmost importance given the developing global population. The carbohydrate biopolymers may play in plant protection against pathogenic fungi by inhibiting spore germination and mycelial growth, may act as effective elicitors inducing the plant immune system to cope with pathogens. Furthermore, they can be utilised as carriers in controlled-release formulations of agrochemicals or other active ingredients, offering an alternative approach to conventional fungicides. It is expected that this review provides an extensive summary of the application of carbohydrates in the realms of food, pharmaceuticals, and environment.

Review on chitosan-based antibacterial hydrogels: Preparation, mechanisms, and applications

Chitosan (CS) is known for its remarkable properties, such as good biocompatibility, biodegradability, and renewability, in addition to its antibacterial and biological activities. However, as CS is insoluble in water, it displays limited antibacterial performance under neutral and physiological conditions. A viable solution to this problem is grafting chemically modified groups onto the CS framework, thereby increasing its solubility and enhancing its antibacterial effect. Herein, the antibacterial action mechanism of CS and its derivatives is reviewed, confirming the prevalent use of composite materials comprising CS and its derivatives as an antibacterial agent. Generally, the antimicrobial ability of CS-based biomaterials can be enhanced by incorporating supplementary polymers and antimicrobial agents. Research on CS-based composite biomaterials is ongoing and numerous types of biomaterials have been reported, including inorganic nanoparticles, antibacterial agents, and CS derivatives. The development of these composite materials has considerably expanded the application of CS-based antibacterial materials. This study reviews the latest progress in research regarding CS-based composite hydrogels for wound repair, tissue engineering, drug release, water purification, and three-dimensional printing applications. Finally, the summary and future outlook of CS-based antibacterial hydrogels are presented in anticipation of a broader range of applications of CS-based antibacterial hydrogels.

One-step fabrication of eco-friendly multi-functional amphiphobic coatings for cellulose-based food packaging

Plastic and fluorine-containing oil and water resistant packaging materials have been gradually replaced by non-toxic and harmless bio-based materials because of their hazard to environment and human health. In this study, chitosan/carnauba wax emulsions (CS/CWs) were firstly prepared by one-step and used as oil and water resistant coating for cellulose-based food packaging paper. The impacts of emulsion components on stability of the emulsions and barrier performance of the coated paper were investigated. The results showed that the viscosity, particle size and polydispersity index of the emulsions were greatly dependent on the concentration of CS and CW, and the coated paper had the best comprehensive performance in water and oil resistance when the concentration of CS was 3 % and the amount of CW was 90 % of the total solid content (CS3/CW90). The particle size of CS3/CW90 was in the range of 0.5-0.7 μm, and the Cobb60 value, water contact angle and the kit ratings of paper coated with CS3/CW90 achieved 7.5 g/m2, 130.9° and 12/12, respectively, and the coated paper also exhibited excellent thermal stability and high antibacterial rate of 99.1 %, demonstrating its great potential for application in multi-functional food packaging.

Effects of the Degree of Phenol Substitution on Molecular Structures and Properties of Chitosan-Phenol-Based Self-Healing Hydrogels

Click chemistry is commonly used to prepare hydrogels, and chitosan-phenol prepared by using a Schiff base has been widely employed in the field of biomaterials. Chitosan-phenol is a derivative of chitosan; the phenol groups can disrupt both the inter- and intramolecular hydrogen bonds in chitosan, thereby reducing its crystallinity and improving its water solubility. In addition, chitosan-phenol exhibits various beneficial physiological functions. However, it is still unclear whether the degree of phenol substitution in the chitosan main chain affects the molecular interactions and structural properties of the self-healing hydrogels. To explore this issue, we investigated the molecular structure and network of self-healing hydrogels composed of chitosan-phenol with varying degrees of phenol substitution and dibenzaldehyde poly(ethylene oxide) (DB-PEO) using molecular dynamics simulations. We observed that when the degree of phenol substitution in the self-healing hydrogel was less than 15%, an increase in the degree of phenol substitution led to an increase in the interactions between chitosan-phenol and DB-PEO, and it enhanced the dynamic covalent bond cross-linking generated through the Schiff base reaction. However, when the degree of phenol substitution exceeded 15%, excessive phenol groups caused excessive intramolecular interactions within chitosan-phenol molecules, which reduced the binding between chitosan-phenol and DB-PEO. Our results revealed the influence of the degree of phenol substitution on the molecular structure of the self-healing hydrogels and showed an optimal degree of phenol substitution. These findings provide important insights for the future design of self-healing hydrogels based on chitosan and should help in enhancing the applicability of hydrogels in the field of biomedicine.

Properties of Paperboard Coated with Natural Polymers and Polymer Blends: Effect of the Number of Coating Layers

Paper is one of the packaging materials that presents a biodegradable character, being used in several areas; however, its barrier properties (gases and fat) and mechanics are reduced, which limits its application. Coating papers with synthetic polymers improve these properties, reducing their biodegradability and recyclability. The objective of this work was to develop and characterize coated paperboard, using the tape casting technique, with different ratios of film form agar-agar/chitosan (AA:CHI, 100:0, 50:50, and 0:100) and different numbers of coating layers (operating times for application of 14.25 min and 28.5 min for one and two layers, respectively). A significant reduction in water absorption capacity was found by applying a 0:100 coating (approximately 15%). Considering all coating formulations, the water vapor permeability reduced by 10 to 60% compared to uncoated paperboard, except for two layers coated with 0:100. The tensile index (independent of AA:CHI) was higher in the machine direction (22.59 to 24.99 MPa) than in the cross-section (11.87-13.01 MPa). Paperboard coated only with chitosan showed superior properties compared to the other formulation coatings evaluated.

A comprehensive review of chitosan applications in paper science and technologies

Using environmentally friendly biomaterials in different aspects of human life has been considered extensively. In this respect, different biomaterials have been identified and different applications have been found for them. Currently, chitosan, the well-known derivative of the second most abundant polysaccharide in the nature (i.e., chitin), has been receiving a lot of attention. This unique biomaterial can be defined as a renewable, high cationic charge density, antibacterial, biodegradable, biocompatible, non-toxic biomaterial with high compatibility with cellulose structure, where it can be used in different applications. This review takes a deep and comprehensive look at chitosan and its derivative applications in different aspects of papermaking.

Development of water-resistant paper using chitosan and plant-based wax extracted from banana leaves

On being exposed to water, cellulose paper swells and its mechanical properties become weak. In this study, natural wax with an average particle size of 12.3 μm extracted from banana leaves was mixed with chitosan to prepare coatings applied on paper surfaces. Chitosan efficiently dispersed banana leaf-extracted wax on paper surfaces. The mixed chitosan and wax coatings considerably influenced paper properties, including yellowness, whiteness, thickness, wettability, water and oil sorption, and mechanical properties. The coating induced hydrophobicity in the paper, resulting in a significant increase in the water contact angle from 65.1 ± 7.7° (uncoated paper) to 123.2 ± 2.1°, and a decrease in water absorption by ⁓64 % to 52.6 ± 1.9 %. The coated paper demonstrated an oil sorption capacity of 212.2 ± 2.8 %, which was ⁓43 % greater than that of the uncoated paper, and the tensile strength of the coated paper improved by 43 % under wet conditions compared to the uncoated paper. Additionally, a separation of oil in water was observed for the chitosan/wax coated paper. Based on these promising results, the paper coated with chitosan and wax could be used for direct-contact packaging applications.

A facile strategy to fabricate antibacterial hydrophobic, high-barrier, cellulose papersheets for food packaging

As a traditionally used packaging material, natural cellulose-based paper has poor barrier properties to water and oxygen, which severely limits its wide application in food packaging. In this study, we report a new sustainable approach to producing hydrophobic, high-barrier, and antibacterial packaging materials from cellulose paper. In this process, commercially available microcrystalline cellulose was first modified by long-chain stearic acid to form hydrophobic microcrystalline cellulose ester and then mixed with stearic acid as filler in the subsequent surface coating of bagasse fibre paper. The microcrystalline cellulose ester/stearic acid-coated paper (MSP) exhibited good water repellency and oxygen barrier activity due to a continuous hydrophobic film that formed, which completely covered the pores of the original bagasse fibre paper. The coated MSP sample also showed excellent dimensional stability in water and a good wet tensile strength of 16 MPa. In addition, poly(hexamethylene guanidine) (PHMG) was chemically grafted onto the free carboxyl groups of the MSP surface layer, and the resulting MSP-g-PHMG samples exhibited excellent antibacterial activity against Escherichia coli and Listeria monocytogenes. The biodegradable cellulose-based MSP-g-PHMG sample significantly delayed the decay of raspberry during storage, indicating its potential application in food packaging.

Effect of Degree of Deacetylation of Chitosan/Chitin on Human Neural Stem Cell Culture

Stem cell therapy and research for neural diseases depends on reliable reproduction of neural stem cells. Chitosan-based materials have been proposed as a substrate for culturing human neural stem cells (hNSCs) in the pursuit of clinically compatible culture conditions that are chemically defined and compliant with good manufacturing practices. The physical and biochemical properties of chitosan and chitin are strongly regulated by the degree of deacetylation (DD). However, the effect of DD on hNSC behavior has not been systematically investigated. In this study, films with DD ranging from 93% to 14% are fabricated with chitosan and chitin. Under xeno-free conditions, hNSCs proliferate preferentially on films with a higher DD, exhibiting adherent morphology and retaining multipotency. Lowering the DD leads to formation of neural stem cell spheroids due to unsteady adhesion. The neural spheroids present NSC multipotency protein expression reduction and cytoplasmic translocation. This study provides an insight into the influence of the DD on hNSCs behavior and may serve as a guideline for hNSC research using chitosan-based biomaterials. It demonstrates the capability of controlling hNSC fate by simply tailoring the DD of chitosan.

Sustainable Coating Paperboard Packaging Material Based on Chitosan, Palmitic Acid, and Activated Carbon: Water Vapor and Fat Barrier Performance

Synthetic polymer coatings impact the biodegradable behavior of cellulosic packaging material. The environmental consequences of food packaging disposal have increased consumer concern. The present study aimed to use natural polymer coatings incorporating palmitic acid and activated carbon applied to paperboard surfaces as a sustainable alternative to improve cellulosic packaging material's moisture and fat barrier properties, minimizing the environmental impact. The coating formulation was defined using a Factorial Experimental Design with independent variables: chitosan, palmitic acid, activated carbon concentrations, and the number of coating layers. The highest concentration of chitosan (2.0% w/w) filled the pores of the cellulosic paperboard network, supporting the compounds incorporated into the filmogenic matrix and improving the fat resistance. The water vapor permeability of the coated paperboard material (range: 101 ± 43 to 221 ± 13 g·d^-1·m^-2) was influenced by the hydrophobicity effect of palmitic acid, the non-polar characteristic of activated carbon, and the number of applied layers. The coating formulation selected was a chitosan concentration of 2.0% (w/w), a palmitic acid concentration of 1.8% (w/w), an activated carbon concentration of 1.2% (w/w), and an application of three layers. The coating provides the potential for a paperboard surface application, improving the cellulosic packaging material's fat and moisture barrier properties and maintaining biodegradability and recyclability.

Trends and challenges in the development of bio-based barrier coating materials for paper/cardboard food packaging; a review

Currently, petroleum-based synthetic plastics are used as a key barrier material in the paper-based packaging of several food and nonfood goods. This widespread usage of plastic as a barrier lining is not only harmful to human and marine health, but it is also polluting the ecosystem. Researchers and food manufacturers are focused on biobased alternatives because of its numerous advantages, including biodegradability, biocompatibility, non-toxicity, and structural flexibility. When used alone or in composites/multilayers, these biobased alternatives provide strong barrier qualities against grease, oxygen, microbes, air, and water. According to the most recent literature reports, biobased polymers for barrier coatings are having difficulty breaking into the business. Technological breakthroughs in the field of bioplastic production and application are rapidly evolving, proffering new options for academics and industry to collaborate and develop sustainable packaging solutions. Existing techniques, such as multilayer coating of nanocomposites, can be improved further by designing them in a more systematic manner to attain the best barrier qualities. Modified nanocellulose, lignin nanoparticles, and bio-polyester are among the most promising future candidates for nanocomposite-based packaging films with high barrier qualities. In this review, the state-of-art and research advancements made in biobased polymeric alternatives such as paper and board barrier coating are summarized. Finally, the existing limitations and potential future development prospects for these biobased polymers as barrier materials are reviewed.

Green-synthesized silver nanoparticle coating on paper for antibacterial and antiviral applications

The use of active packaging has attracted considerable attention over recent years to prevent and decrease the risk of bacterial and viral infection. Thus, this work aims to develop active packaging using a paper coated with green-synthesized silver nanoparticles (AgNPs). Effects of different silver nitrate (AgNO3) concentrations, viz. 50, 100, 150, and 200 mM (AgNPs-50, AgNPs-100, AgNPs-150, and AgNPs-200, respectively), on green synthesis of AgNPs and coated paper properties were investigated. A bio-reducing agent from mangosteen peel extract (ex-Garcinia mangostana (GM)) and citric acid as a crosslinking agent for a starch/polyvinyl alcohol matrix were also used in the synthetic process. The presence of AgNPs, ex-GM, and citric acid indicated the required synergistic antibacterial activities for gram-positive and gram-negative bacteria. The paper coated with AgNPs-150 showed complete inactivation of virus within 1 min. Water resistance and tensile strength of paper improved when being coated with AgNPs-150. The tensile strength of the coated paper was found to be in the same range as that of a common packaging paper. Result revealed that the obtained paper coated with AgNPs was proven to be effective in antibacterial and antiviral activities; hence, it could be used as an active packaging material for items that require manual handling by a number of people.

Bio-based materials for barrier coatings on paper packaging

Research into alternative packaging materials is becoming more and more popular as a result of growing eco-friendly concerns regarding the usage of some petroleum-based polymeric packaging materials and coatings, as well as growing buyer demands for products with nutritious quality and extended shelf lives. Barrier coatings made of naturally renewable biopolymers can be applied to paper packing materials. These biopolymer coatings have the potential to replace the current synthetic paper and paperboard coatings, are strong oxygen and oil barriers, and may prevent the unintended moisture transfer in food goods. An appealing method of controlling the growth and spread of microorganisms in food packaging is the integration of antimicrobial compounds into coatings to create active/functional paper-based packaging materials. Here, in this review of the oxygen/moisture barrier, mechanical, and other characteristics of paper coated with bio-based materials. Examples are used to discuss the current and future uses of bio-based material coatings on paper packaging materials to improve barrier performance.

Chitosan: A Sustainable Material for Multifarious Applications

Due to the versatility of its features and capabilities, chitosan generated from marine crustacean waste is gaining importance and appeal in a wide variety of applications. It was initially used in pharmaceutical and medical applications due to its antibacterial, biocompatible, and biodegradable properties. However, as the demand for innovative materials with environmentally benign properties has increased, the application range of chitosan has expanded, and it is now used in a variety of everyday applications. The most exciting aspect of the chitosan is its bactericidal properties against pathogens, which are prevalent in contaminated water and cause a variety of human ailments. Apart from antimicrobial and water filtration applications, chitosan is used in dentistry, in water filtration membranes to remove metal ions and some heavy metals from industrial effluents, in microbial fuel cell membranes, and in agriculture to maintain moisture in fruits and leaves. It is also used in skin care products and cosmetics as a moisturizer, in conjunction with fertilizer to boost plant immunity, and as a bi-adhesive for bonding woods and metals. As it has the capacity to increase the life span of food items and raw meat, it is an unavoidable component in food packing and preservation. The numerous applications of chitosan are reviewed in this brief study, as well as the approaches used to incorporate chitosan alongside traditional materials and its effect on the outputs.

Chitosan coating for the preparation of multilayer coated paper for food-contact packaging: Wettability, mechanical properties, and overall migration

Cellulose-based paper is an alternative substitution for petroleum-based polymers for packaging applications, but its mechanical performance is poor when in contact with water. Herein, chitosan was applied on cellulose-based paper via a coating approach. The effects of chitosan coatings between none and five layers on the color properties, wettability, thermal properties, mechanical performance, and overall migration in food simulants of the paper were evaluated. After the application of chitosan, chitosan first filled cavities between cellulose fibers within a network, and the chitosan film was formed on the paper surface later. This resulted in a pronounced increase in wettability and mechanical properties associated with a loss of whiteness and an increase in yellowness of the coated paper. The chitosan-coated paper became hydrophobic with a water contact angle of 94.7 ± 2.8°, and a robust improvement of 156.4% for tensile strength and 114.8% for strain at break was observed for the paper coated with three layers of chitosan in wet conditions in comparison to the uncoated paper. A reduction in the migration of the low molecular residuals from the paper could be hindered by the chitosan coating. These enhanced features revealed that chitosan-coated paper could be used as a food-contact material.

Effect of the chitosan second layer on the gelation and controlled digestion of Citrem-chitosan bilayer emulsions

This research aimed to induce repulsive gelation in Citrem-stabilized O/W emulsions by creating a secondary layer of chitosan around the droplets. A range of chitosan concentrations (0-0.25 wt%) and degrees of deacetylation (DDA 50% and 93%) were used to establish the conditions for repulsive gelation in 36 wt% O/W emulsion. The bilayer emulsions were prepared by the electrostatic deposition of positively charged chitosan on negatively charged Citrem-stabilized droplets at pH 4. The droplet size increased from <0.5 μm for the primary emulsion to 5-10 μm at an intermediate chitosan concentration (0.05-0.15 wt%) due to bridging flocculation and again dropped to 1.7-3.6 μm at higher concentrations (0.2 and 0.25 wt%). The droplet charge changed from -48 mV for the primary emulsion to +41.4 and +54.5 mV after surface saturation by DDA 50 and DDA 93 chitosan, respectively. The strain and frequency-dependent rheology indicated that with an increase in the chitosan concentration, emulsions changed from a viscoelastic liquid for monolayer emulsions to strong attractive gel due to bridging flocculation at an intermediate chitosan concentration. At a higher concentration, repulsive gels were formed at complete coverage due to an increase in the effective oil volume fraction towards close packing resulting from the expansion of the interfacial steric barrier and charge cloud thickness. The overall lipid digestibility during in vitro digestion was 25.7% for monolayer emulsions, which decreased with increased chitosan concentration and reached the lowest at surface saturation (17.5%). It was proposed that the formation of the Citrem-chitosan bilayer controlled lipid digestibility by delaying the action of gastric and pancreatic lipases. Such bilayer emulsion gels can be utilized for structure formation in reduced-fat foods.

Development and evaluation of Moringa extract incorporated Chitosan/Guar gum/Poly (vinyl alcohol) active films for food packaging applications

The present study contributes the synthesis of active films with the incorporation of moringa extract (ME) into chitosan (CS)/guar gum (GG)/poly(vinyl alcohol) (PVA) matrix (CGPM) by simple solvent casting technique. The effect of ME on the mechanical, thermal, structural and morphological properties of CGPM active films were investigated. ME has shown a marked influence on the optical, thermal properties and swelling behaviour of CGPM active films. The improvement in the tensile strength of CGPM-1 active film (53.7 MPa) was observed compared to control CS/GG/PVA (CGP) film. DSC study revealed that glass transition temperature (Tg) and melting temperature (Tm) decreased with the addition of ME in the CGP matrix, which confirmed the miscibility among the components of active films. There was an improvement in the thermal stability of the CGPM active films. The FTIR study confirmed the molecular interaction between ME and CS/GG/PVA matrix. The XRD analysis showed a decrease in crystallinity with an increase in the ratio of CS for CGPM active films. The CGPM active films were an excellent barrier to UV- light and have exhibited a decrease in moisture adsorption and water solubility compared to CGP control film. The inclusion of ME in the CGP matrix leads to the formation of a dense compact surface, which in turn enhanced hydrophobicity of active films. The CGPM active films showed minimum WVP, OP values and overall migration values were within the limits of 10 mg/dm2. It was also observed that CGPM active films effectively inhibited the growth of E. coli and S. aureus bacteria. These findings suggest CGPM active films are biodegradable, biocompatible, non-toxic and hence can find application as food packaging materials.

Chemical Proprieties of Biopolymers (Chitin/Chitosan) and Their Synergic Effects with Endophytic Bacillus Species: Unlimited Applications in Agriculture

Over the past decade, reckless usage of synthetic pesticides and fertilizers in agriculture has made the environment and human health progressively vulnerable. This setting leads to the pursuit of other environmentally friendly interventions. Amongst the suggested solutions, the use of chitin and chitosan came about, whether alone or in combination with endophytic bacterial strains. In the framework of this research, we reported an assortment of studies on the physico-chemical properties and potential applications in the agricultural field of two biopolymers extracted from shrimp shells (chitin and chitosan), in addition to their uses as biofertilizers and biostimulators in combination with bacterial strains of the genus Bacillus sp. (having biochemical and enzymatic properties).

Green Packaging from Consumer and Business Perspectives

Sustainable development is a global objective that aims to address the societal challenge of climate action, the environment, resource efficiency, and raw materials. In this sense, an important strategy is the promotion of green packaging, that is, the use of sustainable materials and designs for the packaging of goods. In recent years, many research works have been published in the specialised area covering the different perspectives and dimensions of green packaging. However, to our knowledge, no previous investigations have analysed the research activity on green packaging from business and consumer perspectives. The present study intends to fill this gap by analysing all of the publications found in the Scopus database with the help of visual analytic tools, including word clouds and Gephi network visualization software. More specifically, our study analyses the impact of green packaging from business and consumer viewpoints, including some specific issues such as the design and materials used in green packaging, green packaging costs, marketing strategies and corporate social responsibility related to green packaging, and the impact of green packaging in waste management, the circular economy, logistics, and supply chain management. The results obtained reveal the growing interest of scholars and researchers in all of these dimensions, as is made patently clear by the increasing number of journal publications in recent years. The practical implications of this study are significant, given the growing awareness among companies and consumers about the importance of the promotion of sustainable development through green packaging alternatives. More specifically, the results of this research could be very useful for all of those agents who are interested in learning about the main lines of research being developed in the field of green packaging.

Surface coating of chitosan of different degree of acetylation on non surface sized writing and printing grade paper

Chitosan is a renewable biopolymer which can be applied on the surface of writing and printing (W&P) grade paper to enhance its different properties. A variety of chitosan is available based on degree of acetylation (DA), molecular weight, viscosity, etc. DA has a profound effect on the performance of chitosan in many applications. Present study compared the performance of different DA chitosan for surface application of W&P grade paper. Chitosan samples of 23 %, 16 % and 6% DA were studied for their impact on various physical and surface properties of W&P grade paper. Surface coating of chitosan was done at 1.6 ± 0.2 g/m² (lower dose) and 2.3 ± 0.3 g/m² (higher dose) on W&P grade paper. Some properties including air permeance, TEA, showed considerable effect of DA in which high DA chitosan outperformed the low DA. Broadly, chitosan with different DA had varied impact on individual properties of paper.

Chitosan as a Wound Dressing Starting Material: Antimicrobial Properties and Mode of Action

Fighting bacterial resistance is one of the concerns in modern days, as antibiotics remain the main resource of bacterial control. Data shows that for every antibiotic developed, there is a microorganism that becomes resistant to it. Natural polymers, as the source of antibacterial agents, offer a new way to fight bacterial infection. The advantage over conventional synthetic antibiotics is that natural antimicrobial agents are biocompatible, non-toxic, and inexpensive. Chitosan is one of the natural polymers that represent a very promising source for the development of antimicrobial agents. In addition, chitosan is biodegradable, non-toxic, and most importantly, promotes wound healing, features that makes it suitable as a starting material for wound dressings. This paper reviews the antimicrobial properties of chitosan and describes the mechanisms of action toward microbial cells as well as the interactions with mammalian cells in terms of wound healing process. Finally, the applications of chitosan as a wound-dressing material are discussed along with the current status of chitosan-based wound dressings existing on the market.