A Novel 3D-Printed Microfluidic Bioreactor With Electrospun Scaffold Integration as a Platform for Cardiovascular Tissue Engineering

Cardiovascular diseases are one of the leading causes of global mortality. Treatment methods such as bypass graft operations, while often successful, can fail in cases of systemic disease or compliance mismatch. Tissue engineered vascular grafts may offer a potential solution, by means of an implantable cell-seeded scaffold that can integrate into the graft site. Modifications to the cell culture environment, such as through physical modification of the scaffold structure, or culturing cells in a dynamic fluidic environment, have been shown to alter cellular behavior. Herein, we combine these two approaches by incorporating electrospun polycaprolactone scaffolds consisting of smooth and modified fiber surface topographies within a series of novel 3D printed microfluidic bioreactors. The bioreactors successfully maintained the viability of human umbilical vein endothelial cells over a 24-h period, with the smooth scaffolds in static culture and dimpled scaffolds under dynamic culture indicating the highest cell viability. An increase in stiffness and hydrophilicity of the modified scaffold is also noted in comparison to the scaffold consisting of smooth fibers. These results indicate that both the bioreactor system and the modified electrospun scaffold are capable of inducing variations in cellular response, thus warranting further investigation for the advancement of vascular tissue engineering.