Tissue engineering involves extensive integration of engineering techniques to recover functionality of the dysfunctional or damaged tissues. More conveniently, cell therapy has been widely used where cell aggregates, including 3D cell spheroids, were injected right into the impaired tissues. However, the direct transplantation of the cell spheroids suffers two critical drawbacks, namely the loss and the long-term viability. We hypothesized that both of these issues would be resolved by enveloping the spheroids in a meshed network of vascularization-inducing scaffolds. The PCL-based scaffolds were first fabricated using electrospinning whose structural characteristics were analyzed by SEM. Endothelial cells were then seeded on the scaffolds and cultured for 2-4 days to induce the formation of an engineered vasculature where the phase separation technique was used to modify the surface topology of the fibers for better adhesion of the cells. To test the feasibility of the engineered vasculature as functional seeds to be interconnected to the pre-existing vasculature in vivo, we developed an in vitro tissue model made of Matrigel with pre-formed vessel network, on which the engineered vasculature was patched. After 48 hours, the interconnections between the vasculatures from the tissue-mimic and the PCL-scaffold were verified using immunofluorescence imaging. In this research, we suggest a new strategy for vascularization in an engineered tissue to help the sustained viability of the implanted tissue or tissue constructs.