3D printable Gel-inks for Tissue Engineering: Chemistry, Processing, and Applications

Preface
About This Book
Contents
About the Editors
1 Introduction to 3D Printing Technology for Biomedical Applications
	1 Introduction
	2 Printing Mechanism: Classification of 3D Printing Techniques
		2.1 Selective Laser Sintering
		2.2 Stereolithography
		2.3 Fused Deposition Modeling
		2.4 Ink-Jet Printing
	3 Evolution of 3D-Printed Medical Objects—Then and Now
	4 3D Printable Materials for Medical Applications
	5 Significance of 3D-Printed Objects in the Medical Field
	6 Applications of 3D Printing
		6.1 3D Printing of Surgical Preparation
		6.2 Custom-Made Prosthetics
		6.3 Dental
		6.4 3D Printing of Tissues, Organoids, and Tissue Regeneration
		6.5 Medication Dosage and Pharmacology
		6.6 Manufacturing of Surgical Tools and Medical Metal Materials
	7 Potential and Major Limitations
	References
2 Characterization of Bioinks for 3D Bioprinting
	1 Bioink Definition, Related Terms
	2 Properties of Bioinks
		2.1 Bioink for Extrusion-Based Bioprinting
		2.2 Bioink for Laser-Based Bioprinting
		2.3 Bioink for Droplet-Based Bioink
	3 Characterization of Bioinks
		3.1 Rheology
		3.2 Printability
		3.3 Biofabrication Window
		3.4 Cell Density
		3.5 Cytocompatibility and Functionality
		3.6 Bioink Purity
		3.7 Bioink Degradation
		3.8 Viscosity and Molecular Weight
		3.9 Bioink Homogeneity
		3.10 Solubility
		3.11 Spheroid Characterization
	4 Conclusion and Future Prospects
	References
3 3D Printing of Hydrogel Constructs Toward Targeted Development in Tissue Engineering
	1 Introduction
	2 3D Printing Technologies for Hydrogel Inks
		2.1 Light-Assisted Direct-Printing
		2.2 Inkjet Printing
		2.3 Direct Dispensing
	3 Trends and Strategies in Designing Hydrogel-Based Inks
		3.1 Single-Component Hydrogel Inks
		3.2 Bi-Component Hydrogel Inks
		3.3 Nanocomposite Hydrogel Inks
		3.4 Multicomponent Hydrogel Inks
		3.5 Cell-Embedding and the Bio-Printability Window
	4 Key Parameters in Designing Printable Hydrogel Formulation
		4.1 Material Parameters
		4.2 Crosslinking Strategies
		4.3 Fabrication Parameters
		4.4 Investigation of Printability
	5 Evolution to 4D Printing
	References
4 Three-Dimensional Self-healing Scaffolds for Tissue Engineering Applications
	1 Introduction
	2 Understanding Nature’s Method of Self-healing
	3 Self-healing Supramolecular Hydrogels
	4 Self-assembled Hydrogels for Tissue Engineering and Drug Delivery Applications
	5 Supramolecular Chemistry
		5.1 Hydrogen Bonding
		5.2 Metal–Ligand Coordination Complexation
		5.3 Electrostatic Interaction
		5.4 Host–Guest Interactions
	6 π–π Interactions
	7 Bioinspired Systems Chemistry
	8 Conclusion
	References
5 Gel-Inks for 3D Printing in Corneal Tissue Engineering
	1 Introduction
		1.1 Structure of the Cornea
		1.2 Desired Qualities for Cornea Replacement
	2 Corneal Regeneration in Tissue Engineering
		2.1 Scaffold-Based Tissue Engineering for Corneal Regeneration
		2.2 Synthetic Biomaterials for Corneal Regeneration
		2.3 Corneal Regeneration Using Naturally Derived Biomaterials
	3 Corneal Regeneration Using Gel-Based Scaffolds
		3.1 Desired Properties of Gel-Inks for 3D Printing in Corneal Tissue Engineering
		3.2 Biocompatible 3D-Printing Techniques for Bioinks Design
	4 Combination and Characterization of Gel-Inks for in Corneal Regeneration
		4.1 Rheological and Printability Examinations
		4.2 Light Transmission Examination
		4.3 Mechanical Characterizations
		4.4 Biocompatibility Assessment
		4.5 Oxygen Permeability
	5 Conclusion and Future Perspectives
	References
6 Three Dimensional (3D) Printable Gel-Inks for Skin Tissue Regeneration
	1 Introduction
	2 Skin: A Histological Overview
		2.1 Epidermis
		2.2 Basement Membrane
	3 Skin Wound Healing: What We Know and Need to Know
	4 Bioengineered Skin Substitutes
		4.1 Epidermal Substitutes
		4.2 Dermal Substitutes
		4.3 Dermo-Epidermal Substitutes
	5 Advanced Strategies for Skin Repair and Regeneration
		5.1 Top-Down Approaches for Skin Regeneration
		5.2 Bottom-Up Approaches for Skin Regeneration
		5.3 Laser-Assisted 3D Bioprinting
		5.4 Drop-Based Bioprinting
		5.5 Extrusion-Based Bioprinting
		5.6 Stereolithography-Based Bioprinting
		5.7 Electrohydrodynamic-Based Bioprinting
		5.8 Microfluidic-Based Bioprinting
	6 Natural 3D Printable Gel-Inks for Skin Regeneration
		6.1 Alginate
		6.2 Collagen
		6.3 Gelatin
		6.4 Chitosan
		6.5 Silk Fibroin
		6.6 Decellularized Extracellular Matrix (dECM)
	7 Synthetic 3D Printable Gel-Inks for Skin Regeneration
		7.1 Poly(ε-caprolactone) (PCL)
		7.2 Poly(Lactic Acid) (PLA)
		7.3 Polyurethane (PU)
	8 Conclusion
	References
7 Biofunctional Inks for 3D Printing in Skin Tissue Engineering
	1 Introduction
	2 The Structure and Function of Skin
	3 Wound Types and Wound Healing Process
	4 Skin Tissue Engineering
	5 Overview of 3D Bioprinting
		5.1 3D Bioprinting Technologies
	6 3D Skin Bioprinting
		6.1 Design Considerations for Skin Bioprinting
	7 Biofunctional Inks for Bioprinting in Skin Tissue Engineering
		7.1 Natural Bioinks
		7.2 Bioinks Based on Synthetic Polymers
	8 Current Challenges and Advances in Developing of Biofunctional Inks in Skin Tissue Engineering
	9 Conclusion
	References
8 Bioceramic-Starch Paste Design for Additive Manufacturing and Alternative Fabrication Methods Applied for Developing Biomedical Scaffolds
	1 Introduction
	2 Starch
	3 Bioceramics-Starch Pastes
		3.1 Oxide Ceramics and Starch
		3.2 Glasses and Glass–Ceramics and Starch
		3.3 Calcium Phosphates and Starch
	4 Conventional Methods for Bioceramic Scaffold Fabrication
	5 Additive Manufacturing for Bioceramic Scaffold Fabrication
	6 Bone Scaffold Prototype with Hydroxyapatite and Starch
		6.1 Technology Description
		6.2 Raw Ceramic Preparation
		6.3 Powder Preparation and Processing
		6.4 Scaffold Design
		6.5 Forming, Processing, and Sintering
		6.6 Prototype Morphology
	7 Conclusions
	References
9 Additive Manufacturing of Bioceramic Scaffolds for Bone Tissue Regeneration with Emphasis on Stereolithographic Processing
	1 Scaffolds for Bone Repair: An Overview
	2 Scaffold Requirements
		2.1 Biocompatibility
		2.2 Porosity
		2.3 Mechanical Properties
		2.4 Biodegradability
		2.5 Surface Properties and Interaction with Cells
	3 Conventional Methods for Ceramic Scaffold Fabrication
		3.1 Foaming Methods
		3.2 Phase Separation Methods
		3.3 Spinning Methods
		3.4 Thermal Consolidation of Particles
		3.5 Sponge Replica Method
	4 Additive Manufacturing Technologies for Ceramic Scaffold Fabrication
	5 Stereolithographic Methods
		5.1 Processing
		5.2 The Slurry: Composition and Characteristics
		5.3 The Photopolymerization Process: Chemical Basis
		5.4 Key Parameters for the Photopolymerization Process
		5.5 Post-processing
		5.6 SLA: Advantages and Disadvantages
	6 The Latest Frontier: Digital Light Processing (DLP)-Based Stereolithography
		6.1 System Setup
		6.2 Digital Micro-mirror Device (DMD)
	7 Current Applications of SLA- and DLP-Derived Ceramic Scaffolds
	8 Conclusions
	References
10 3D Printable Gel-Inks for Microbes and Microbial Structures
	1 Introduction
	2 Bioprinting
	3 Bioprinting Techniques
	4 Bioprinting Materials
	5 Bioprinting and Microbes
		5.1 Viruses
		5.2 Bacteria and Bacterial Structures
	6 Summary and Concluding Remarks
	References
11 Methods of Polysaccharides Crosslinking: Future-Promising Crosslinking Techniques of Alginate Hydrogels for 3D Printing in Biomedical Applications
	1 Introduction
	2 Types of Polysaccharides
		2.1 Sulfated Polysaccharides
		2.2 Non-sulfated Polysaccharides
	3 Methods for Crosslinking the Polysaccharides
		3.1 Physical Crosslinking
		3.2 Chemical Crosslinking
	4 Some Applications of 3D-Based Cosslinking Alginate Hydrogels in Biomedicine
		4.1 Tissue Engineering
		4.2 Wound Dressing
		4.3 Drug Delivery
	5 Summary
	References
12 Future Perspectives for Gel-Inks for 3D Printing in Tissue Engineering
	1 Introduction
	2 From Biomaterials to Tissue Engineering
	3 Future Perspectives for 3D Bioprinting
	4 Conclusions
	References