Alginate is a hydrophilic, biocompatible, biodegradable, and relatively economical polymer generally found in marine brown algae. The modification in the alginate molecule after polymerization has shown strong potential in biomedical, pharmaceutical and biotechnology applications such as wound dressing, drug delivery, dental treatment, in cell culture and tissue engineering. Besides this, alginates have industrial applications too in the paper and food industries as plasticizers and additives.
The few books that have been published on alginates focus more on their biology. This current book focuses on the exploration of alginates and their modification, characterization, derivatives, composites, hydrogels as well as the new and emerging applications.Table of Contents
Preface xv
Part 1: Alginates - Introduction, Characterization and Properties 1
1 Alginates: General Introduction and Properties 3
Rutika Sehgal, Akshita Mehta and Reena Gupta
1.1 Introduction 4
1.2 History 4
1.3 Structure 4
1.4 Alginates and Their Properties 6
1.4.1 Gel Formation 6
1.4.1.1 Ionic Alginate Gels 6
1.4.1.2 Alginic Acid Gels 8
1.4.2 Molecular Weight 8
1.4.3 Solubility and Viscosity 8
1.4.4 Ionic Cross-Linking 9
1.4.5 Chemical Properties 9
1.5 Sources 11
1.6 Biosynthesis of Bacterial Alginate 11
1.6.1 Precursor Synthesis 12
1.6.2 Polymerization and Cytoplasmic Membrane Transfer 13
1.6.3 Periplasmic Transfer and Modification 15
1.6.3.1 Transacetylases 15
1.6.3.2 Mannuronan C 5-Epimerases 16
1.6.3.3 Lyases 16
1.6.5 Export through the Outer Membrane 16
1.7 Conclusion 16
Acknowledgment 17
Conflict of Interests 17
References 17
2 Alginates Production, Characterization and Modification 21
Pintu Pandit, T. N. Gayatri and Baburaj Regubalan
2.1 Introduction 22
2.2 Alginate: Production 24
2.2.1 Screening of Alginate-Producing Microbes 24
2.2.2 Production of Alginate by Bacteria 25
2.2.3 Production of Alginate by Pseudomonas 26
2.2.4 Production of Alginate by Azotobacter spp. 26
2.2.5 Influence of Medium Components 26
2.2.5.1 Effect of Nutrients on Bacterial Alginate Production 26
2.2.5.2 Effect of Phosphate on Bacterial Alginate Production 27
2.2.5.3 Effect of Dissolved Oxygen on Bacterial Alginate Production 27
2.2.5.4 Effect of Agitation in the Medium for the Production of Alginate 27
2.2.6 Commercial Production of Alginate 28
2.3 Characterization of Physicochemical Properties of Alginate 28
2.3.1 Composition of Alginate Polymer Chains 29
2.3.2 XRD, FTIR, and NMR Spectroscopy for Alginate Structure Analysis 31
2.3.3 Rheology and Mechanical Characterization of Alginate Gels and Solutions 32
2.4 Modification of Alginates 33
2.4.1 Chemical Modification 33
2.4.2 Oxidation 34
2.4.3 Sulfation 34
2.4.4 Phosphorylation 35
2.4.5 Graft Copolymerization 35
2.4.6 Esterification 35
2.4.7 Carbodiimide Coupling 36
2.4.8 Covalent Cross-Linking 36
2.5 Future Perspectives 38
2.6 Conclusions 39
References 39
3 Alginate: Recent Progress and Technological Prospects 45
Tanvir Arfin and Kamini Sonawane
3.1 Introduction 45
3.2 Structure 46
3.3 Sources 47
3.4 Characteristics of Alginate Salts 48
3.5 Properties 48
3.6 Applications 50
3.7 Future Perspectives 53
3.8 Advantages 54
3.9 Disadvantages 54
3.10 Conclusion 54
Acknowledgments 55
References 55
4 Alginate Hydrogel and Aerogel 59
Ajith James Jose, Kavya Mohan and Alice Vavachan
4.1 Introduction 59
4.2 Alginate Hydrogel 60
4.2.1 Preparation of Alginate Hydrogels 61
4.2.1.1 Ionic Cross-Linking 62
4.2.1.2 Covalent Cross-Linking 62
4.2.1.3 Thermal Gelation 62
4.2.1.4 Cell Cross-Linking 63
4.2.2 Biomedical Applications 63
4.2.2.1 Pharmaceutical Applications 63
4.2.3 Tissue Regeneration with Protein and Cell Delivery 68
4.2.3.1 Blood Vessels 68
4.2.3.2 Bones 69
4.2.3.3 Cartilage 69
4.2.3.4 Muscle, Nerve, Pancreas, and Liver 70
4.3 Alginate Aerogel 70
4.3.1 Properties of Alginate Aerogels 71
4.3.1.1 Bulk Density and Pore Volume 71
4.3.1.2 Specific Surface Area 71
4.3.1.3 Compressibility 71
4.3.1.4 Thermal Conductivity and Absorption 72
4.3.2 Preparative Methods 72
4.4 Future Perspectives 73
References 73
Part 2: Alginates in Biomedical Applications 79
5 Alginate in Biomedical Applications 81
Luiz Pereira da Costa
5.1 Introduction 81
5.2 Chemical Structure and Properties of Alginate 83
5.3 Types of Interaction of Alginate 84
5.4 Biomedical Application of Alginates 87
5.5 Future Perspective of the Use and Biomedical Applications 90
References 90
6 Alginates in Pharmaceutical and Biomedical Application: A Critique 95
Vivek Dave, Kajal Tak, Chavi Gupta, Kanika Verma and Swapnil Sharma
6.1 Introduction 95
6.2 Structure of Alginate 96
6.3 Different Types of Alginates Used in Pharmaceutical Industries 97
6.4 Properties of Alginate 98
6.5 Pathway for the Biosynthesis of Alginate 98
6.6 Regulatory Consideration of Alginate 100
6.7 Applications 100
6.7.1 Other Applications 113
6.8 Conclusion 114
References 115
7 Alginates in Evolution of Restorative Dentistry 125
S.C. Onwubu, P.S. Mdluli, S. Singh and Y. Ngombane
7.1 Introduction 125
7.2 Method of Alginate Extraction 126
7.3 Evolution of Alginate in Restorative Dentistry 128
7.3.1 Problems with Conventional Alginate 129
7.3.2 Current Trends and Modification of Alginate 129
7.3.2.1 Extended Pour Time Alginate 130
7.3.2.2 Dust-Free Alginates 130
7.3.2.3 Infection-Free Alginates 132
7.3.2.4 High Viscosity Alginates 132
7.3.2.5 Alginates in Two Pastes Form 133
7.3.2.6 Tray Adhesive Alginates 133
7.4 The Art of Impression Taking Using Alginates 133
7.4.1 Selection of Impression Trays 134
7.4.2 Mixing and Loading Alginates 135
7.4.3 Preparation of the Oral Cavity before Impression Taking 135
7.4.4 Impression Taking Using Alginate Material 136
7.4.5 Removal and Inspection of Alginate Material 137
7.4.6 Effects of Cast Production Techniques 137
7.5 Conclusions 138
References 138
8 Alginates in Drug Delivery 141
Srijita Basumallick
8.1 Introduction 141
8.2 Chemistry of Alginates 142
8.2.1 Hydrogel Formation by Alginates 143
8.2.1.1 Preparation of Hydrogel 143
8.3 Pharmaceutical and Biomedical Chemistry of Alginates 144
8.3.1 Factors Governing Drug Encapsulation and Drug Delivery Processes 145
8.3.1.1 Delivery and Encapsulation of Small Drugs 145
8.3.1.2 Macromolecular Drug Delivery by Alginates 148
8.4 Conclusions 149
Acknowledgments 149
References 149
9 Alginate in Wound Care 153
Satyaranjan Bairagi and S. Wazed Ali
9.1 Introduction 154
9.2 Sources and Synthesis of Alginate 154
9.3 Physicochemical Properties of the Alginate Biopolymer 156
9.4 Biomedical Applications of Alginate 157
9.4.1 Alginate in Wound Care 158
9.4.1.1 Pure Alginate Polymer-Based Wound Dressing 160
9.4.1.2 Intercellular Mediators Incorporated Alginate Polymer-Based Wound Dressing 160
9.4.1.3 Zinc/Alginate- and Silver/Alginate-Based Wound Dressing 161
9.4.1.4 Chitosan/Alginate- and Collagen/Alginate-Based Wound Dressing 163
9.4.1.5 Alginate Fiber-Based Wound Dressing 163
9.4.1.6 Alginate Hydrogel-Based Wound Dressing 167
9.5 Opportunities and Future Thrust 172
References 173
10 Alginate-Based Biomaterials for Bio-Medical Applications 179
Reena Antil, Ritu Hooda, Minakshi Sharm and Pushpa Dahiya
10.1 Introduction 180
10.2 Alginate: General Properties 180
10.2.1 Chemical Properties, Structure, and Characterization 181
10.3 Extraction and Preparation 182
10.3.1 Gelation and Cross-Linking of Alginate 183
10.3.2 Ionic Cross-Linking 184
10.3.3 External Gelation 184
10.3.4 Internal Gelation 185
10.3.5 Covalent Cross-Linking 185
10.3.6 Large Bead Preparation 186
10.3.7 Microbead Preparation 186
10.4 Alginate Hydrogels 187
10.5 Photocross-Linking 188
10.6 Shape-Memory Alginate Scaffolds 188
10.7 Biodegradation of Alginate 189
10.8 Biomedical Application of Alginates 190
10.8.1 Controlled Chemical and Protein Drug Delivery 190
10.8.2 Wound/Injury Dressings 193
10.8.3 Cell Culture 194
10.8.4 Tissue Regeneration 195
References 196
Part 3: Alginates in Food Industry 205
11 Alginates for Food Packaging Applications 207
Radhika Theagarajan, Sayantani Dutta, J.A. Moses and C. Anandharamakrishnan
11.1 Introduction 207
11.2 Biopolymer in Food Industry 208
11.3 Alginates in Food Packaging 209
11.4 Biosynthesis of Alginate 213
11.5 Application of Alginate in Formation of Biofilm 215
11.5.1 Preparation of Packaging Films 215
11.5.2 Role of Alginate in Biofilm Formation 215
11.6 Packaging Properties of Alginate 217
11.6.1 Thermostability of Alginate Packaging 218
11.6.2 Water Solubility 218
11.6.3 Water Vapor Permeability 218
11.6.4 Tensile Strength 218
11.6.5 Oxygen Permeability 219
11.6.6 Barrier Property 219
11.6.7 Antimicrobial Activity 219
11.7 Effect of Alginate on the Quality of Food 222
11.8 Interaction between Food and Alginates 223
11.9 Environmental Effects on Alginate Packaging 224
11.10 Market Outlook 224
11.11 Conclusion 225
References 226
12 Potential Application of Alginates in the Beverage Industry 233
S. Vijayalakshmi, S.K. Sivakamasundari, J.A. Moses and C. Anandharamakrishnan
12.1 Introduction 233
12.2 Alginate Source 234
12.3 Extraction of Alginates 235
12.4 Physical, Chemical and Functional Properties of Alginate 236
12.5 Uses as a Food Additive/Ingredient 241
12.6 Alginate as Stabilizer 245
12.7 As Encapsulating Wall Material 247
12.7.1 Immobilization of Biocatalysts 249
12.7.2 Probiotics 250
12.7.3 Improvement of the Alginate Encapsulation: Prebiotics Addition 253
12.8 Conclusion 254
References 254
13 Alginates in Comestibles 263
Ashwini Ravi, S. Vijayanand, Velu Rajeshkannan, S. Aisverya, K. Sangeetha, P.N. Sudha and J. Hemapriya
13.1 Introduction 264
13.2 Alginates in Agricultural Marketing 265
13.3 Use of Alginates in Food Industry 266
13.3.1 Thickeners and Gelling Agents 267
13.3.2 Stabilizers and Emulsifiers 268
13.3.3 Texturizers 269
13.3.4 Encapsulation 269
13.3.5 Food Coating 270
13.4 Use of Alginates for Pets 271
13.5 Effect of Dietary Alginates 271
13.6 Alginate Safety 272
13.7 Conclusion 272
References 272
Part 4: Alginates Future Prospects 281
14 Alginates: Current Uses and Future Perspective 283
Ashwini Ravi, S. Vijayanand, G. Ramya, A. Shyamala, Velu Rajeshkannan, S. Aisverya, P.N. Sudha and J. Hemapriya
14.1 Introduction 284
14.2 Sources of Alginate Synthesis 285
14.2.1 Brown Seaweeds 285
14.2.2 Bacteria 287
14.3 Synthesis of Alginate 288
14.3.1 Alginate Biosynthesis Gene 289
14.4 Properties of Alginates 290
14.4.1 Molecular Weight 290
14.4.2 Solubility 291
14.4.3 Stability 291
14.4.4 Ionic Binding Property 292
14.4.5 Gel Formation Ability 293
14.4.6 Biological Properties 293
14.5 Application of Alginates 294
14.6 Future Perspectives of Alginates 295
14.6.1 3D-Based Cell Culture Systems 295
14.6.2 Impressions 296
14.6.3 Cell-Based Microparticles 296
14.6.4 Alginate Oligosaccharides 298
14.6.5 Drug Targeting 299
14.6.6 Nanoparticulate Systems 300
14.7 Conclusion 300
References 300
Index 313
