Chitin and Chitosan: Properties and Applications

1. Sources of chitin and chitosan and their isolation 1.1. Chitin and chitosan 1.1.1. Chemical structure 1.1.2. Different crystalline forms of chitin 1.2. Sources of chitin and chitosan 1.2.1. Sources of chitin 1.2.1.1. Crustaceans (part of Arthropoda) 1.2.1.2. Insects (part of Arthropoda) 1.2.1.3. Others sources 1.2.2. Sources for chitosan 1.3. Isolation of chitin 1.3.1. Technology principles 1.3.2. Pre-treatment 1.3.3. Demineralisation 1.3.4. Deproteination 1.3.5. Decoloration & other post treatment processes 1.3.6. Isolation of chitin from Crustaceans 1.3.7. Isolation of chitin from insects 1.3.8. Isolation of chitin from other biomass types 1.4. Production of chitosan 1.4.1. Conversion of chitin to chitosan 1.4.1.1. Deacetylation reaction mechanism 1.4.1.2. Chemical deacetylation process 1.4.1.3. Tailoring deacetylation degrees of chitosan 1.4.1.4. Deacetylation drawbacks and alternative methods 1.4.2. Chitosan extracted from Fungi 1.4.2.1. Pretreatment 1.4.2.2. Alkali based "cleaning" 1.4.2.3. Chitosan extraction and post treatment 1.5. Towards commercial applications 1.6. Outlook References 2. Methods of isolating chitin from sponges (Porifera) 2.1. Introduction 2.2. Brief overview of classical methods of isolating chitin from invertebrates 2.3. The modern approach to chitin isolation from sponges 2.3.1. Methods of isolating chitin from glass sponges (Hexactinellida) 2.3.2. Methods of isolating chitin from demosponges (Demospongiae) 2.3.2.1. Demineralisation as a crucial step in chitin isolation from demosponges 2.3.2.2. Ultrasonic treatment in the isolation of chitin from demosponges 2.3.2.3. Microwave-assisted methods for chitin isolation from demosponges 2.4. Prospective applications of poriferan chitin 2.4.1. Poriferan chitin and modern bioinspired materials science 2.4.2. Chitinous 3D scaffolds of sponge origin for tissue engineering 2.5. Outlook Acknowledgment References 3. Physicochemical properties of chitosan and its degradation products 3.1. Physicochemical properties of chitosan 3.1.1. Determination of molar mass 3.1.1.1. Determination of molar mass by GPC/SEC 3.1.1.2. Determination of the viscometric average molar mass 3.1.2. Determination of the deacetylation degree 3.1.2.1. Estimation of DD by nuclear magnetic resonance (NMR) method 3.1.2.2. Estimation of DD by Fourier-Transform Infrared Spectroscopy (FTIR) 3.1.2.3. Determination of DD by potentiometric titration method 3.1.2.4. Determination of DD by a linear potentiometric titration method 3.1.2.5. Determination of DD of the first derivative of the UV spectrum method 3.1.3. Determination of dynamic viscosity 3.1.4. Determination of nitrogen 3.1.5. Determination of ash content 3.1.6. Determination of heavy metal content 3.1.7. Determination of water retention value (WRV) 3.1.8. Determination of solubility in hydrochloric acid 3.1.9. Determination of water content 3.1.10. Determination of protein content 3.1.11. Quantitative determination of chitosan by ninhydrin 3.2. Products of degradation and their application 3.3. Outlook References 4. New developments in the analysis of partially acetylated chitosan polymers and oligomers 4.1. Introduction 4.2. Chitosan oligomers 4.2.1. Degree of polymerisation (DP), fraction and pattern of acetylation (FA and PA) 4.3. Chitosan polymers 4.3.1. Molecular weight (MW) / degree of polymerisation (DP) and its dispersity (?MW / ?DP) 4.3.2. Fraction of acetylation (FA) and its dispersity (?FA) 4.3.3. Pattern of acetylation (PA) 4.4. Outlook References 5. Chitosan-based hydrogels 5.1. Introduction 5.2. Chitosan-based multi-layered hydrogels 5.2.1. Periodic precipitation 5.2.2. Alternating process 5.2.3. Induced by electrical signals 5.2.4. Layer-by-Layer (LbL) assembly 5.2.5. Sequential curing 5.3. Chitin/chitosan physical hydrogels based on alkali/urea solvent system 5.3.1. Chitin hydrogels based on alkali/urea solvent system 5.3.2. Chitosan hydrogels based on alkali/urea solvent system 5.4. Chitosan-based injectable hydrogels 5.4.1. Physical association networks 5.4.1.1. Ionic interactions 5.4.1.2. Hydrogen bonds 5.4.1.3. Hydrophobic associations 5.4.2. Chemical association networks 5.4.2.1. Schiff-base reaction 5.4.2.2. Phenylboronate ester bond 5.4.2.3. Click reaction 5.4.2.4. Light-triggered radical cross-linking 5.4.2.5. Enzyme-mediated gelation 5.4.3. Double-network hydrogels 5.5. Chitosan-based self-healing hydrogels 5.5.1. Physical interactions 5.5.1.1. Ionic interactions 5.5.1.2. Hydrogen bonds 5.5.1.3. Other physical interactions 5.5.2. Dynamic chemical bonds 5.5.2.1. Imine bonds 5.5.2.2. Acylhydrazone bonds 5.5.2.3. Other dynamic covalent bonds 5.6. Chitosan-based shape memory hydrogels 5.6.1. Water / solvent-triggered shape recovery 5.6.2. pH-triggered shape recovery 5.6.3. Ultrasound triggered shape recovery 5.6.4. Self-actuated shape memory hydrogels 5.6.5. Chitosan based hydrogels with triple shape memory effect 5.7. Superabsorbent chitosan-based hydrogels 5.7.1. Crosslinked chitosan-based hydrogels 5.7.2. Hydrogels by graft copolymerization 5.7.3. Chitosan-based composite hydrogels 5.7.3.1. Inorganic-chitosan composites 5.7.3.2. Organic-chitosan composites 5.7.4. Pure chitosan-based materials 5.8. Outlook References 6. Beneficial health effects of chitin and chitosan 6.1. Immunomodulatory effects of chitin and chitosan as demonstrated with in vitro studies 6.2. Beneficial health effects mediated by chitin and chitosan as demonstrated with animal studies 6.2.1. Immune modulation 6.2.2. Anti-pathogenic effects 6.2.3. Anti-tumour effects 6.3. Beneficial health effects mediated by chitin and chitosan as demonstrated with clinical trials 6.3.1. Cholesterol reduction and CVD preventive effects 6.3.2. Other health effects 6.4. Requirements to forward the field of study towards the beneficial health effects of chitin and chitosan 6.5. Outlook Acknowledgement References 7. Antimicrobial properties of chitin and chitosan 7.1. Microbiological activity of chitosan - the mechanism of its antibacterial and antifungal activity 7.2. The use of chitin/chitosan microbiological activity in medicine and pharmacy 7.3. Microbiological activity of chitosan in the food industry 7.4. Microbiological activity of chitosan in paper and textile industries 7.5. Microbiological activity of chitosan in agriculture 7.6. Outlook References 8. Enzymes for modification of chitin and chitosan 8.1. CAZymes in chitin degradation and modification 8.1.1. Chitinases 8.1.2. ß-N-acetylhexosaminidases 8.1.3. Exo-ß-glucosaminidases 8.1.4. Chitosanases 8.1.5. Lytic polysaccharide monooxygenases 8.1.6. Carbohydrate esterases 8.1.7. Carbohydrate-binding modules 8.2. Modular diversity in chitinases, chitosanases and LPMOs 8.3. Biological roles of chitin-active enzymes 8.4. Microbial degradation and utilization of chitin 8.4.1. Chitin degradation by Serratia marcescens 8.4.2. Chitin degradation by bacteria in the Bacteriodetes phylum 8.4.3. Chitin degradation by Thermococcus kodakaraensis 8.4.4. Chitin degradation by fungi 8.5. Biotechnological perspectives 8.6. Biorefining of chitin-rich biomass 8.7. Outlook References 9. Chitin and chitosan as source of biobased building blocks and chemicals 9.1. Introduction 9.2. Chitin conversion into chitosan, chitin oligosaccharides and monosaccharides 9.2.1. Chitosan production 9.2.2. Production of chitooligosaccharides 9.2.3. Production of GlcNAc and GlcN from chitin 9.3. Building blocks for polymers from chitin and its derivatives 9.3.1. Furan-based monomers 9.3.2. Amino alcohol and amino acid building blocks 9.4. Outlook Acknowledgment References 10. Chemical and enzymatic modification of chitosan to produce new functional materials with improved properties 10.1. Introduction 10.2. Functional chitosan derivatives by chemical and enzymatic modification 10.2.1 Anionic chitosan derivatives 10.2.2. Hydroxyalkyl chitosans 10.2.3. Quaternized and highly cationic chitosan derivatives 10.2.4. Hydroxyaryl chitosan derivatives 10.2.5. Carbohydrate-modified chitosan 10.3. Graft co-polymers of chitosan 10.4. Cross-linked chitosan and chitosan polymer networks 10.5. Outlook References 11. Chitosan-based drug delivery systems 11.1. Introduction 11.2. Beneficial effects of chitosan 11.2.1. Interaction with anionic drugs 11.2.2. Mucoadhesive properties 11.2.3. Transfection activity 11.2.4. Efflux pump inhibitory properties 11.2.5. Permeation enhancing properties 11.3. Chitosan - an active polymer for by-passing biological barriers 11.3.1. Skin barrier 11.3.2. Mucosa barrier 11.3.2.1. Nasal mucosa 11.3.2.2. Barriers encountered in oral delivery 11.3.2.3. Vaginal mucosa 11.3.3. Ophthalmic barrier 11.3.4. Blood-brain barrier 11.4. Chitosan-based DDS formulations 11.4.1. Hydrogels 11.4.2. Micro/nanoparticles 11.4.3. Nanofibres 11.4.4. Scaffolds and membranes 11.5. Outlook Acknowledgement References 12. The application of chitin and its derivatives for the design of advanced medical devices 12.1. Selection of the raw sources. Safety criteria 12.1.1. Aspect of animal tissue originated derivatives 12.1.2. General requirements for chitinous biopolymers applied in designing medical devices 12.1.3. Characterization of the biopolymer for application in wound dressing designing 12.1.4. Aspect of the sterilization of the final wound dressing 12.2. Types of wound dressing consisting of chitin derived biopolymers available on the market 12.3. Performance and safety assessment 12.4. New ideas and concepts 12.5. Risk acceptance and design process aspects 12.6. Outlook Acknowledgement References 13. Food applications of chitosan and derivatives 13.1. Introduction 13.2. Chitosan and its derivatives as food additive 13.2.1. Antioxidant 13.2.2. Antimicrobial 13.2.3. Stabilizer and thickener 13.3. Functional ingredient and health beneficial effects 13.4. Active Packaging 13.5. Enzyme immobilization 13.6. Encapsulation and delivering of bioactive ingredients 13.7. Adsorption and chelation of toxic and undesirable compounds 13.8. Outlook References 14. Potential of chitosans in the development of edible food packaging 14.1. Potential limitations for real introduction into the market 14.1.1. Generally Recognized As Safe (GRAS) 14.1.2. Solubility 14.1.3. Source - origin 14.1.4. Structure variability 14.2. Films and coatings for food preservation 14.2.1. Definitions and interests 14.2.2. Main relevant chitosan-based material properties 14.2.2.1. Surface properties/Adhesion properties for coatings 14.2.2.2. Possibility of using the layer-by-layer technique (LbL) 14.2.2.3. Mechanical and barrier properties 14.2.2.4. Inherent antimicrobial properties 14.2.2.5. Carrier properties 14.3. Specific case of chitosan nanoparticles 14.3.1. Chitosan nanoparticles 14.3.2. Chitosan nanoparticles in various edible films 14.3.3. Antimicrobial activities of chitosan nanoparticles in edible films 14.3.4. Toxicity studies of chitosan nanoparticles 14.4. Applications to sensitive real food products 14.4.1. Fruits and vegetables 14.4.2. Meat and meat products 14.4.3. Fish and see food products 14.5. Conclusions References 15. The use of chitosan based nanoformulations for controlling fungi during storage of horticultural commodities 15.1. Introduction 15.2. Importance of fruit and vegetables 15.3. Storage disorders and diseases of horticultural products 15.4. Plant fungi inhibition by chitosan application 15.5. Chitosan integrated with other alternative methods for controlling postharvest fungi 15.6. Chitosan-based formulations 15.7. Physiological response and quality retention of horticultural commodities to chitosan coating application 15.8. Influence of chitosan coatings on the shelf life of horticultural products 15.9. Effect of chitosan coatings with additional compounds on quality and microorganisms' development 15.10. Integration of chitosan nanoparticles into coating formulations and effect on horticultural commodities' quality and microorganisms' development 15.11. Outlook Acknowledgements References 16. Chitosan application in textile processing and fabric coating 16.1. Chitosan in the textile industry 16.2. Textile production 16.3. General test methods 16.4. Fibers and yarns from chitin and chitosan 16.4.1. Chitin and chitosan solubilization for spinning purposes 16.4.2. Chitosan spinning processes 16.4.3. Mechanical properties of chitosan fibers/yarns 16.5. Sizing with chitosan 16.5.1. Miscibility of chitosan with other sizing agents 16.5.2. Viscosity of chitosan-containing sizing agents 16.5.3. Adhesion and wetting 16.5.4. Mechanical-physical properties of chitosan films 16.5.5. Removal and processing of chitosan sizing after weaving 16.6. Chitosan as finishing agent or coating 16.6.1. Chitosan as carrier and linker 16.6.2. Formation of a durable finish with chitosan 16.6.3. Chitosan as active agent 16.6.3.1. Antibacterial coating 16.6.3.2. Removal of heavy metals and dyes 16.6.3.3. Increased dyeability of textiles 16.6.3.4. Improved crease resistance, anti-felting properties and crease recovery angles 16.7. Outlook Nomenclature References 17. Chitin and chitosan for water purification 17.1. Introduction 17.2. Wastewater treatment by adsorption 17.2.1. Principle of adsorption process 17.2.2. Adsorption of organic compounds 17.2.3. Adsorption of heavy metals 17.3. Wastewater treatment by coagulation/flocculation 17.4. Wastewater treatment by membrane separation 17.4.1. Principle of ultrafiltration process 17.4.2. Fabrication of ultrafiltration blend membranes 17.4.3. Chitosan enhanced ultrafiltration 17.5 Outlook Acknowledgement References 18. Chitosan for sensors and electrochemical applications 18.1. Introduction 18.2. Chitosan: a biopolymer with unique properties 18.3. Modification and preparation of chitosan-based materials for electrochemical applications 18.4. The proton conductivity of chitosan 18.5. Selected applications 18.5.1. Electrochemical sensors 18.5.2. Spectroscopic sensors 18.5.3. Other electrochemical devices 18.6. Outlook References 19. Marketing and regulations of chitin and chitosan from insects 19.1. Historical outline 19.2. Natural origins of chitin 19.3. Specificities of chitin biopolymer 19.4. Differences between chitin from insects and other sources 19.4.1. Differences of chemical composition of the cuticle 19.4.2. Differences of physical assembly of chains and molecules 19.5. Extraction and purification specificities of chitin from insects 19.5.1. Different cuticle structures and contents of insects 19.5.2. Chemical extraction 19.5.3. Biological extraction 19.5.4. Characterization and transformation into chitosan 19.6. Market opportunities and its regulations 19.6.1. Agriculture applications 19.6.2. Water treatment applications 19.6.3. Materials applications 19.6.3.1. Food packaging 19.6.3.2. Other materials applications 19.6.4. Biomedical applications 19.6.4.1. Human health 19.6.4.2. Animal health 19.7 19.7. Outlook References