Cardiovascular diseases are the leading cause of deaths throughout the world. 
Vascular diseases are mostly treated with autografts and blood vessel 
transplantations. However, traditional grafting methods have several problems 
including lack of suitable harvest sites, additional surgical costs for 
harvesting procedure, pain, infection, lack of donors, and even no substitutes 
at all. Recently, tissue engineering and regenerative medicine approaches are 
used to regenerate damaged or diseased tissues. Most of the tissue engineering 
investigations have been based on the cell seeding into scaffolds by providing a 
suitable environment for cell attachment, proliferation, and differentiation. 
Because of the challenges such as difficulties in seeding cells spatially, 
rejection, and inflammation of biomaterials used, the recent tissue engineering 
studies focus on scaffold-free techniques. In this paper, the development of 
novel computer aided algorithms and methods are developed for 3D bioprinting of 
scaffold-free biomimetic macrovascular structures. Computer model mimicking a 
real human aorta is generated using imaging techniques and the proposed 
computational algorithms. An optimized three-dimensional bioprinting path 
planning are developed with the proposed self-supported model. Mouse embryonic 
fibroblast (MEF) cell aggregates and support structures (hydrogels) are 3D 
bioprinted layer-by-layer according to the proposed self-supported method to 
form an aortic tissue construct.