Biomedical Engineering Reference
In-Depth Information
4
Rapid Prototyping Methods for
Tissue Engineering Applications
Giovanni Vozzi and Arti Ahluwalia
CONTENTS
4.1 Introduction.............................................................................................................................
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4.2 Microfabrication of Three-Dimensional Structures: Rapid Prototyping................................
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4.3 Materials Used for Tissue Engineering Scaffolds ..................................................................
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4.4 Resolution and Resolution/Time of Manufacture Ratio and Geometry .................................
99
4.5 Fluid-Based RP Microfabrication .........................................................................................
100
4.5.1 Pressure-Assisted Microsyringe System ...................................................................
101
4.5.2 Fused Deposition Modeling ......................................................................................
102
4.5.3 Organ Printing...........................................................................................................
103
4.6 Printing Head and Powder-Based Microfabrication .............................................................
104
4.6.1 Membrane Lamination ..............................................................................................
104
4.6.2 Three-Dimensional Printing .....................................................................................
105
4.6.3 Laser Sintering ..........................................................................................................
106
4.6.4 Photopolymerization..................................................................................................
107
4.7 Other RP Methods ................................................................................................................
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4.7.1 Sacrifi cial Molds........................................................................................................
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4.7.2 Electrospinning .........................................................................................................
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4.8 Integration of RP Methods....................................................................................................
110
4.9 Commercial RP Systems for Tissue Engineering Scaffolds.................................................
110
4.10 Discussion: Limitations and Critiques ..................................................................................
111
4.11 Conclusion.............................................................................................................................
112
References ......................................................................................................................................
113
4.1 INTRODUCTION
Tissue engineering can be defi ned as the development of biological substitutes to restore, maintain,
or improve tissue functions and is based on the application of principles and methods of engineer-
ing and life sciences toward a fundamental understanding of structure-function relationships in
normal and pathological mammalian tissues. This is an emerging interdisciplinary area of research
and technology that has the potential of revolutionizing our methods of health care treatment and
dramatically improving the quality of life for millions of people throughout the world. Several
approaches to tissue engineering have been established of which the most common approach is
based on scaffold-guided tissue formation
in vitro
. A scaffold is a biodegradable and biocompatible
three-dimensional (3-D) porous structure, which can support cell adhesion and growth. Typically
cells are seeded onto biodegradable polymeric scaffolds, and the constructs in some way reform
the intrinsic tissue structures [1]. The scaffold approach to tissue engineering fi rst emerged in the
early 1990s, and since then much of the work has focused on scaffolds in the form of sponges
or foams, which possess a random microstructure. More recently as a result of a hypothesis that
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