Despite significant progress in the field of tissue engineering within the last decade, a number of unsolved problems still remain. One of the most relevant issues is the lack of proper vascularization that limits the size of engineered tissues to smaller than clinically relevant dimensions. In particular, the growth of engineered tissue in vitro within bioreactors is plagued with this challenge. Specifically, the tubular perfusion system bioreactor has been used for large scale bone constructs; however these engineered constructs lack inherent vasculature and quickly develop a hypoxic core, where no nutrient exchange can occur, thus leading to cell death. Through the use of 3D printed vascular templates in conjunction with a tubular perfusion system bioreactor, we attempt to create an endothelial cell monolayer on 3D scaffolds that could potentially serve as the foundation of inherent vasculature within these engineered bone grafts.