Organ printing or biomedical application of rapid prototyping, also defined as 
additive layer-by-layer biomanufacturing, is an emerging transforming technology 
that has potential for surpassing traditional solid scaffold-based tissue 
engineering. Organ printing has certain advantages: it is an automated approach 
that offers a pathway for scalable reproducible mass production of tissue 
engineered products; it allows a precised simultaneous 3D positioning of several 
cell types; it enables creation tissue with a high level of cell density; it can 
solve the problem of vascularization in thick tissue constructs; finally, organ 
printing can be done in situ. The ultimate goal of organ-printing technology is 
to fabricate 3D vascularized functional living human organs suitable for 
clinical implantation. The main practical outcomes of organ-printing technology 
are industrial scalable robotic biofabrication of complex human tissues and 
organs, automated tissue-based in vitro assays for clinical diagnostics, drug 
discovery and drug toxicity, and complex in vitro models of human diseases. This 
article describes conceptual framework and recent developments in organ-printing 
technology, outlines main technological barriers and challenges, and presents 
potential future practical applications.