Additive manufacturing, otherwise known as three-dimensional (3D) printing, is 
driving major innovations in many areas, such as engineering, manufacturing, 
art, education and medicine. Recent advances have enabled 3D printing of 
biocompatible materials, cells and supporting components into complex 3D 
functional living tissues. 3D bioprinting is being applied to regenerative 
medicine to address the need for tissues and organs suitable for 
transplantation. Compared with non-biological printing, 3D bioprinting involves 
additional complexities, such as the choice of materials, cell types, growth and 
differentiation factors, and technical challenges related to the sensitivities 
of living cells and the construction of tissues. Addressing these complexities 
requires the integration of technologies from the fields of engineering, 
biomaterials science, cell biology, physics and medicine. 3D bioprinting has 
already been used for the generation and transplantation of several tissues, 
including multilayered skin, bone, vascular grafts, tracheal splints, heart 
tissue and cartilaginous structures. Other applications include developing 
high-throughput 3D-bioprinted tissue models for research, drug discovery and 
toxicology.