3D Printing of Hydrogel Constructs Toward Targeted Development in Tissue Engineering

The venture to design a biomaterial to be functional and compatible to human physiology faces numerous challenges in shaping its properties to emulate the macro- and microstructural organization of the natural tissue. Hydrogels are widely considered the closest possible assemblies that could be bioengineered into complex artificial tissues due to their ability to cope more efficiently with the imposed mechanical, morphological, and biological requirements. The use of the three-dimensional (3D) printing technology for the fabrication of biological models facilitated further developments in tissue engineering. These computer-aided techniques enable the design and fabrication of complex structures to meet user-specified requirements. Research on printable formulations really took off in the late decade and there is still an increased interest in discovering most appropriate biomaterial ink. This chapter provides an overview of the latest developments in hydrogel-based inks and describes the factors that are generally considered to have the most influential effect over the printing process. Herein, current 3D printing ink formulations intended for tissue engineering are discussed in hand with printing strategies, focusing on the correlation of the fluid properties of polymeric hydrogel precursors with key control factors and printing performance. The chapter highlights the exhilarating capability of hydrogels to be fabricated as 3D accurate constructs by surveying the representative advances in designing hydrophilic 3D networks for biomedical application.