Fabrication of a Compliant Vascular Graft Using Extrusion Printing and Electrospinning Technique

Small-diameter vascular grafts having biomechanical properties similar to those of native arteries for the treatment of cardiovascular diseases are still elusive. Here, a hybrid extrusion printing and electrospinning technique is presented in which a layer of electrospun nanofibers is deposited over the printed gelatin-methacryloyl (gelMA) constructs to improve the mechanical performance of gelMA grafts. Various blends of polycaprolactone (PCL) and poly(L-lactide-co-ε-caprolactone) (PLCL) polymer solutions are used to produce electrospun nanofibers. The variation of gelMA concentration is found to have a negligible role in the overall strength of the graft. It is shown that the burst pressure and tensile strength of the fiber-reinforced gelMA constructs are comparable to those of native human arteries. Moreover, the compliance of grafts reinforced by 100% PCL and 75/25% PCL/PLCL nanofibers are found to be similar to human muscular arteries and elastic arteries, respectively. The cytocompatibility assessment shows that gelMA presents a bioactive surface for the endothelial cells to survive and grow. Also, PCL/PLCL electrospun nanofibers offer cellular metabolic activity in the same order of magnitude as observed in the control. Therefore, this hybrid technique opens up new possibilities for the fabrication of tubular constructs in tissue engineering.