Author Biography xiii
Preface xv
1 The Extraction of Alginate from Brown Seaweeds 1
1.1 Introduction 1
1.2 Global Distribution of Brown Seaweeds 2
1.3 The Extraction of Alginate from Brown Seaweeds 6
1.3.1 General Description of the Extraction Process 6
1.3.2 A Comparison of Alginic Acid Method and Calcium Alginate Method 9
1.3.3 Process Control 9
1.3.4 Key Process Parameters 10
1.3.4.1 Size Reduction of Raw Materials 10
1.3.4.2 Acid Treatment 10
1.3.4.3 Formaldehyde Treatment 12
1.3.4.4 Alkaline Extraction 12
1.3.4.5 Separation of Alginate from Insoluble Seaweed Residue 12
1.4 Ultrapure Alginate 14
1.5 Summary 15
References 15
Further Reading 17
2 Chemical, Physical, and Biological Properties of Alginic Materials 19
2.1 Introduction 19
2.2 The Chemical Structure of Alginic Acid 19
2.2.1 Early Studies and Basic Structural Feature 19
2.2.2 M/G Ratio and Distribution 20
2.2.3 C-5 Epimerization and Designer Alginate 21
2.2.4 Molecular Weight and Distribution 22
2.2.5 Chemical Stability 22
2.3 Physical Properties of Alginic Materials 24
2.4 Viscosity of Alginate Solutions 26
2.4.1 Effect of Molecular Weight on Solution Viscosity 26
2.4.2 Effect of Concentration on Solution Viscosity 27
2.4.3 Effect of Temperature on Solution Viscosity 28
2.4.4 Effect of Shear Rate on Solution Viscosity 28
2.4.5 Effect of Salt on Solution Viscosity 28
2.4.6 Effect of pH on Solution Viscosity 29
2.5 Polyelectrolyte Properties 29
2.6 The Ion-Exchange Properties of Alginate 29
2.7 Gelling Properties of Alginate 31
2.8 Film-Forming Properties 32
2.9 Fiber-Forming Properties 33
2.10 Bioactivities of Alginic Materials 33
2.10.1 Enzyme Inhibition Activities of Alginate 33
2.10.2 Biocompatibility and Cell Activities of Alginate 34
2.11 Summary 35
References 35
3 Industrial Applications of Alginic Materials 39
3.1 Introduction 39
3.2 Functional Properties of Alginic Material 39
3.2.1 Alginate as a Thickening Agent 39
3.2.2 Alginate as a Gelling Agent 40
3.2.3 Alginate as a Film-Forming Agent 40
3.2.4 Alginate as a Stabilizer 41
3.2.5 Alginate for Encapsulation and Immobilization 41
3.3 Industrial Applications of Alginate 42
3.3.1 Food Ingredients 42
3.3.2 Medical and Pharmaceutical Uses 44
3.3.2.1 Dental Impression 44
3.3.2.2 Therapeutic Cell Entrapment 45
3.3.2.3 Controlled Release of Drugs 45
3.3.2.4 Alginate Oligoelectrolytes as a Mucin Polymer Network Modifier 45
3.3.2.5 Oligoguluronates as Modifiers of Cystic Fibrosis Mucus 45
3.3.3 Wound Dressings and Hemostatic Agent 46
3.3.4 Immobilization of Biocatalysts 46
3.3.5 Controlled Release of Active Agents 48
3.3.6 Textile Printing Paste 48
3.3.7 Sizing Agent for Paper 48
3.3.8 Coating for Welding Rods 49
3.3.9 Binders for Fish Feed 50
3.3.10 Biostimulants 50
3.4 Summary 50
References 51
4 The Production of Fibers From Alginate 57
4.1 Introduction 57
4.2 The Properties of Alginate as a Fiber-Forming Polymer 58
4.3 Preparation of the Spinning Solutions 60
4.3.1 Molecular Weight of the Alginate Powder 60
4.3.2 Concentration of the Spinning Solution 61
4.3.3 Temperature of the Spinning Solution 61
4.3.4 pH of the Spinning Solution 61
4.4 The Production of Calcium Alginate Fibers 61
4.5 The Production of Calcium Sodium Alginate Fibers 65
4.6 The Production of Sodium Alginate Fibers 66
4.7 The Production of Alginic Acid Fibers 68
4.8 The Production of Zinc Alginate Fibers 69
4.9 The Production of Alginate Fibers Containing Pectin and Carboxymethyl Cellulose 69
4.10 The Production of Silver-Containing Alginate Fibers 71
4.11 The Production of Other Novel Alginate Fibers 73
4.12 Historical Development of Alginate Fibers 76
4.13 Summary 78
References 78
5 Ion-Exchange and Gel-Forming Properties of Alginate Fibers 83
5.1 Introduction 83
5.2 Characterization Methods for Ion Exchange and Gel Forming Properties 83
5.3 Ion-Exchange Properties of Alginate Fibers 86
5.3.1 Ion-Exchange Between Calcium Alginate Fibers and Sodium Ions 86
5.3.2 Ion-Exchange Between Alginate Fibers and Zinc Ions 87
5.3.3 Ion-Exchange Between Alginate Fibers and Copper Ions 91
5.4 Gelling Properties of Alginate Fibers 94
5.5 Summary 98
References 99
6 Applications of Alginate Fibers as Smart Woundcare Materials 101
6.1 Introduction 101
6.2 Functional Requirements of the Wound Dressings 103
6.3 Modern Advanced Wound Dressings 106
6.3.1 Chitin and Chitosan Fibers and Wound Dressings 107
6.3.2 Superabsorbent Cellulosic Fibers 108
6.3.3 Polyurethane Film and Foam 109
6.3.4 Hydrogels 110
6.3.5 Hydrocolloids 111
6.3.6 Activated Carbon 112
6.3.7 Low Adherent Dressings 113
6.3.8 Composite Wound Care Products 114
6.3.9 Antimicrobial Wound Dressings 116
6.3.10 Interactive Dressings 117
6.3.11 Tissue-Engineered “Skin Equivalents” 117
6.3.12 Cell-Containing Matrices 117
6.4 Applications of Alginate Fibers in Functional Wound Dressings 118
6.5 Development of Alginate Wound Dressings 119
6.6 Summary 121
References 123
Further Reading 124
7 Absorption and Interactive Properties of Alginate Wound Dressings 125
7.1 Introduction 125
7.2 Characterization Methods 126
7.2.1 Test on Absorbency 126
7.2.2 Fiber Calcium and Sodium Contents 127
7.2.3 Gel Swelling 127
7.2.4 Wet Integrity 127
7.2.5 Wicking Behavior 127
7.2.6 Dry and Wet Strength 128
7.3 Absorption of Wound Fluid by Alginate-Based Wound Dressings 128
7.3.1 Absorption Mechanism of Alginate Wound Dressings 128
7.3.2 Absorbency of the Various Types of Alginate Wound Dressings 129
7.3.3 Fluid Retention Between Fibers and Inside Fibers 130
7.3.4 A Comparison of Absorption Properties Between Alginate Felt and Rope 131
7.3.5 Effect of Sterilization on the Absorption Properties of Alginate Dressings 131
7.3.6 Effect of Guluronate and Mannuronate Contents 132
7.3.7 Effect of Calcium and Sodium Contents 133
7.3.8 Effect of Nonwoven Structures 133
7.3.9 Effect of Adding CMC Into the Alginate Fibers 134
7.3.10 Wicking of Fluid 135
7.3.11 Dry and Wet Strength 137
7.4 Interactive Properties of Alginate Wound Dressings 138
7.4.1 Interactive Moisture Handling Properties of Alginate Wound Dressings 138
7.4.2 Biologically Interactive Properties of Alginate Wound Dressings 138
7.4.3 Enzyme Inhibition Properties of Alginate Wound Dressings 139
7.5 Summary 142
References 143
8 Clinical Applications of Alginate Wound Dressings 145
8.1 Introduction 145
8.2 Biocompatibility and Bioactivities of Alginate Wound Dressings 145
8.3 Wound Healing Mechanisms of Alginate Wound Dressings 147
8.4 Clinical Applications of Alginate Wound Dressings 148
8.4.1 Applications of Alginate Wound Dressings in Pressure Ulcers 149
8.4.2 Applications of Alginate Wound Dressings in Leg Ulcers 149
8.4.3 Applications of Alginate Wound Dressings in Diabetic Foot Ulcers 151
8.4.4 Applications of Alginate Wound Dressings in Burn Wounds and Donor Sites 151
8.4.5 Applications of Alginate Wound Dressings as a Hemostatic Agent for Bleeding Wounds 154
8.4.6 Applications of Alginate Wound Dressings in Surgical Wounds 156
8.4.7 Applications of Alginate Wound Dressings in Nose Surgery 158
8.4.8 Applications of Alginate Wound Dressings in Anal Fistula Surgery 159
8.4.9 Applications of Alginate Wound Dressings in Cavity Wounds 160
8.4.10 Applications of Alginate-Based Composite Wound Dressings 160
8.5 Main Properties of Alginate Wound Dressings 160
8.5.1 Wound-Healing Promotion 161
8.5.2 The Hemostatic Properties of Alginate Wound Dressing 162
8.5.3 Pain Relief Properties of Alginate Wound Dressing 162
8.5.4 The Antimicrobial Properties of Alginate Wound Dressing 163
8.5.5 Alginate Wound Dressings as Cavity Filler 163
8.5.6 Cost-Effectiveness of Alginate Wound Dressings 163
8.6 Summary 163
References 163
9 Functional Modifications of Alginate Fibers and Wound Dressings 169
9.1 Introduction 169
9.2 Chemical Modification of Alginic Acid 169
9.2.1 Chemical Modification of the Hydroxyl Groups 170
9.2.1.1 Oxidation 170
9.2.1.2 Reductive-Amination of Oxidized Alginate 171
9.2.1.3 Sulfation 172
9.2.1.4 Cyclodextrin-Linked Alginate 172
9.2.1.5 Acetylation of Alginate 172
9.2.1.6 Phosphorylation of Alginates 173
9.2.2 Chemical Modification of the Carboxyl Groups 173
9.2.2.1 Esterification 173
9.2.2.2 Amidation 174
9.2.3 Other Chemical Modifications 175
9.2.3.1 Organic Soluble Derivative of Alginate 175
9.2.3.2 Attachment of Cell Signaling Molecules 175
9.2.3.3 Covalent Cross-linking of Alginates 176
9.2.3.4 Graft Copolymerization of Alginates 177
9.3 Innovations in the Fiber-Making Process 178
9.3.1 The Production of Alginate Fibers Containing Metal Ions and Inorganic Compounds 179
9.3.2 The Production of Polyblend Fibers of Alginate and Other Polymers 180
9.3.3 The Production of Alginate Fibers Through Electrospinning 180
9.3.4 The Production of Alginate Fibers Containing Drugs 182
9.3.5 The Production of Alginate and Chitosan Composite Fibers 183
9.4 Summary 185
References 186
10 Silver-Containing Alginate Fibers and Wound Dressings 193
10.1 Introduction 193
10.2 Antimicrobial Efficacy of Silver 194
10.3 Development of Silver-Containing Wound Dressings 195
10.4 Applications of Silver in Alginate Fibers and Wound Dressings 197
10.4.1 Types of Silver Compounds Used in Wound Dressings 197
10.4.2 Methods for Adding Silver to Wound Dressings 198
10.4.3 Examples of Silver-Containing Wound Dressings 199
10.4.3.1 Acticoat from Smith & Nephew 199
10.4.3.2 Silvercel from Johnson & Johnson 199
10.4.3.3 Aquacel Ag from ConvaTec 200
10.4.3.4 Contreet Foam from Coloplast 200
10.4.3.5 Silverlon from Argentum Medical 200
10.4.3.6 SilvaSorb from Medline 200
10.4.3.7 Urgotul SSD from Laboratoires URGO 200
10.4.3.8 Actisorb Silver 220 from Johnson & Johnson 200
10.4.3.9 Microbisan from Lendell Manufacturing Inc. 201
10.4.4 Differences Between Silver-Containing Wound Dressings 201
10.4.4.1 Different Silver Compounds 201
10.4.4.2 Different Contact Areas 202
10.4.4.3 Different Absorption Capacities 202
10.5 Preparation of Silver-Containing Alginate Fibers and Wound Dressings 203
10.5.1 The Addition of Silver Into Alginate Fibers Through Chemical Reaction 203
10.5.2 The Addition of Silver Into Alginate Fibers Through Blending 203
10.6 Release of Silver Ions from Silver-Containing Alginate Fibers 204
10.7 The Antimicrobial Effect of Silver-Containing Alginate Fibers and Wound Dressings 205
10.8 Properties and Applications of Silver-Containing Alginate Wound Dressings 206
10.8.1 Wound Healing Properties of Silver 206
10.8.2 The Release of Silver from Silver-Containing Wound Dressings 206
10.9 Test Methods for Assessing the Antimicrobial Properties of the Silver Dressing 208
10.9.1 Zone of Inhibition 208
10.9.2 Challenge Testing 208
10.9.3 Microbial Transmission Test 209
10.10 In Vitro and In Vivo Findings of the Clinical Benefits of Silver in Wound Healing 210
10.11 Local and Systemic Toxicity of Silver in Wound Healing 211
10.12 Clinical Efficacy of the Silver-Containing Dressings 212
10.13 Summary 213
References 213
A Appendix A: List of Silver Containing Wound Dressings 217
B Appendix B: Answers to Commonly Asked Questions About Alginate Wound Dressings 221
B. 1 What Are Alginic Acid, Sodium Alginate, and Calcium Alginate? 221
B. 2 What Do M and G Mean With Alginate Fibers and Wound Dressings? 221
B. 3 What Are the Differences Between Alginate Wound Dressing and Calcium Alginate Wound Dressing? 222
B. 4 How Can Calcium Alginate Dressing Form Hydrogel on Contact With Wound Exudate? 223
B. 5 What Role Does Alginate Wound Dressings Play in “Moist Healing”? 223
B. 6 What Are the Main Applications of Alginate Wound Dressings? 223
B. 7 What Is the Absorption Mechanism of Alginate Wound Dressing? 226
B. 8 What Is the Reason That Calcium Alginate Fibers Do Not Gel in Pure Water? 226
B. 9 What Are the Differences Between the Absorption of Wound Exudate by Cotton Gauze and Alginate Wound Dressings? 227
B. 10 What Are the Differences Between High G and High M Alginate Fibers When They Are Applied on Exuding Wounds? 227
B. 11 Can Sodium Alginate Be Absorbed by the Body When Calcium Alginate Fibers Are Converted Into Sodium Alginate Upon Contact With Wound Exudate? 228
B. 12 Alginate Wound Dressings Are Divided Into Wet Integral and Wet Dispersible, What Does These Two Types Mean? 228
B. 13 How Can Alginate Wound Dressings Reduce Pain? 229
B. 14 Are There Any Inappropriate Consequences for the Residue Alginate Fibers Left on the Wound Surface? 229
B. 15 Are There Any Differences Between the Alginate Wound Dressings Under Different Brands? 229
B. 16 In the Manufacturing Processes, What Do Nip Rolling, Needle Punching, and Freeze Drying Mean? 230
B. 17 Can Alginate Wound Dressings Be Used in Combination With Topical Medicines Such as Anti-inflammatory Drugs Like Iodine? 230
B.18 Can Alginate Wound Dressings Be Used on Infected Wounds? 230
B.19 Can Alginate Wound Dressings Be Cut Into Pieces Before Being Applied to Wounds? 231
B.20 What Should Be Done When Alginate Wound Dressings Adhere to the Wound Surface? 231
B.21 Some Patients Experience Granulation Edema When Applied With Alginate Wound Dressings, Is This Related to the Release of Calcium Ions by the Dressing? 231
B.22 What Are the Clinical Efficacy of Alginate Wound Dressings When Used for Pressure Sore Wounds? 231
B.23 What Are the Clinical Efficacy of Alginate Wound Dressings When Used for Leg Ulcer Wounds? 231
B.24 What Are the Clinical Efficacy of Alginate Wound Dressings When Used for Diabetic Foot Ulcer Wounds? 232
B.25 What Are the Clinical Efficacy of Alginate Wound Dressings When Used for Burn Wounds? 232
B.26 What Are the Clinical Efficacy of Alginate Wound Dressings When Used for Anal Fistula Wounds? 232
B.27 Does Alginate Wound Dressing Possess Hemostatic Properties? 232
B.28 Where Are the Seaweeds Used in the Production of Alginate Wound Dressings Come From? 233
Index 235
