۱- Introduction

۲- Deposition techniques for 3D printing of biomaterials

۳- Materials for 3D printing of biomaterials

۴- Applications of 3D printed biomaterials

۵- ۴D printing and its applications for biomaterials

۶- Conclusions and future perspectives

References

Introduction

Three-dimensional printing (3D printing) or additive manufacturing (AM) promises to produce complex devices formulated from biomaterials and bioinspired materials from designs that are patient-specific. Since its advent as presurgical visualization technique and fabrication of tooling molds, 3D printing has evolved to yield bespoke devices, implants, scaffolds, diagnostic devices, and drug-delivery systems. As a result of recent public interest and affordable printing platforms, there is the desire to utilize this exciting technology for personalized health care. However, before AM can become a ubiquitous tool for the regeneration of complex tissues, such as bone, cartilage, muscles, vessels, nerves, and complex organs with multifaceted three-dimensional microarchitecture (e.g., kidneys, lymphoid organs), a number of technological limitations must be overcome. The development of advanced bioinks for 3D and 4D printing through the rational design of novel materials and their implementation as functional biomaterials through ever-expanding deposition techniques has improved the diversity and functionality of printed constructs outside of the traditional biofabrication window [1]. While there is the necessity for a compromise between suitability for purpose and biocompatibility, recent developments in materials science and bioink formulations have resulted in an improved range of solutions for biofabrication platforms. New biologically relevant printing formulations with highly consistent and accurate deposition parameters, attractive mechanical properties, high cytocompatibility, and the ability to modulate cellular functions are now being developed and offer prospects as biomaterials for use in a multitude of different applications; however, further work is needed before these novel materials become common place. In this chapter, we explore some of the approaches being pursued to achieve these targets in common 3D and 4D printing techniques, including an overview of the state-of-the-art technologies and formulations used in novel materials and bioinks, which are currently being developed, the techniques which are being utilized to produce 3D and 4D constructs, and the applications for which these new materials may be employed in. Key examples are highlighted to demonstrate the progress of this emerging technology and limitations to its development identified.