Study on Microextrusion-based 3D Bioprinting and Bioink Crosslinking Mechanisms (eBook)

Supervisor’s Foreword 6
Parts of this Thesis have been Published in the Following Documents: 8
Journal Publications: 8
Acknowledgements 9
Contents 11
Abbreviations 14
1 Introduction 16
1.1 Motivation 16
1.2 Scope and Contents 17
1.3 Chapter Outline 19
References 20
2 3D Bioprinting and Bioink: Background 22
2.1 Concepts and History 22
2.2 State of the Art 24
2.2.1 Bioprinting Technologies 24
2.2.2 Bioinks 29
2.2.3 Applications 32
2.3 Challenges and Perspectives 33
2.3.1 Bioprinting Technologies 34
2.3.2 Bioinks 34
2.3.3 Tissue Maturation 35
References 35
3 Materials and Methods 39
3.1 Process Analysis and Questions Refining 39
3.2 General Criteria for Bioinks and 3D Bioprinting Process 41
3.2.1 Bioink Injectability and Smooth Extrusion 42
3.2.2 Gel Filament Generation 42
3.2.3 Structural Integrity 43
3.2.4 Cell Damage Control 43
3.3 General Design of Bioinks and 3D Bioprinting Process 44
3.3.1 Bioinks and the Crosslinking Mechanism 44
3.3.2 3D Model Design 45
3.3.3 Process Design 46
3.4 Research Methodology 47
3.4.1 General Research Route 47
3.4.2 Rheological Characterization 47
3.4.3 3D Printability Characterization 48
3.4.4 Shear Stress Determination 49
3.4.5 Other Experimental Methods 51
References 55
4 3D Bioprinting of Shear-Thinning Self-assembly Bioink 57
4.1 Bioink Preparation and Characterization 58
4.1.1 Guest–Host Chemistry Modification of Hyaluronic Acid 58
4.1.2 Methacrylation of Hyaluronic Acid 59
4.1.3 Preparation of Bioinks 59
4.1.4 Rheological Characterization 60
4.1.5 3D Bioprinting Process Design 62
4.2 Printability and Stability 64
4.2.1 Gel Filament Generation 64
4.2.2 Structure Stabilization 70
4.3 Cytocompatibility 72
4.3.1 Cell Seeding 72
4.3.2 Direct Cell Printing 73
References 75
5 3D Bioprinting of Thermal-Sensitive Bioink 76
5.1 Bioink Preparation and Characterization 76
5.1.1 Preparation of Gelatin-Based Bioink 76
5.1.2 Rheological Characterization 78
5.1.3 3D Bioprinting Process Design 80
5.2 Printability and Stability 82
5.2.1 Gel Filament Generation 82
5.2.2 Structure Stability 85
5.3 Cytocompatibility 87
5.3.1 Cell Viability of Different Cells 87
5.3.2 Effect of Printing Parameters 89
5.3.3 Effect of Shear Stress 90
5.4 Conjunction of Structure Printability and Cell Viability 91
References 93
6 3D Bioprinting of Non-viscous Bioink 94
6.1 Strategy Optimization 95
6.1.1 Crosslinking Mechanisms 95
6.1.2 Light-Permeable Needle 98
6.1.3 Printing Setup 99
6.1.4 Printing Process 99
6.2 3D Printability and Stability 100
6.2.1 Gel Filament Generation 100
6.2.2 3D Structure Fabrication 102
6.2.3 Structure Stabilization 105
6.3 Cytocompatibility 108
6.4 Generalization to Other Bioinks 109
6.4.1 Bioink Preparation 109
6.4.2 Rheological Characterization 111
6.4.3 Printability and Cytocompatibility 112
6.5 Complex Filament Generation 114
References 116
7 Biological Characterization and Applications 118
7.1 Comparison of Different Technologies 118
7.2 Cell Activity and Proliferation 120
7.2.1 Long-Term Cell Activity 120
7.2.2 Cell Proliferation in 3D 122
7.3 Signal Pathway Activation 124
7.3.1 Cell Transfection 124
7.3.2 Protein Expression of Activator Cells 124
7.3.3 Activation of Reporter Cells 125
7.4 Embryoid Body Formation 126
7.4.1 Embryoid Body Growth 127
7.4.2 Morphology Characterization of Embryoid Body 128
7.4.3 Maintenance of Pluripotency 130
7.4.4 Comparison with Conventional Methods 131
7.5 Cell Behavior Modulation 134
7.5.1 Material Cues 134
7.5.2 Cell Response 135
References 138
8 Conclusions and Future Work 139
8.1 Concluding Remarks 139
8.2 Future Research Directions 141