Examination of the Impact of Polymer Composition and the Test Direction on Tensile Properties of Bilayer Vascular Grafts Using a Multilevel Full Factorial Design Approach

Abstract

Currently, there are no effective commercially available synthetic small-diameter vascular grafts (<6 mm) for bypassing coronary or carotid arteries. This has encouraged ongoing research efforts to create a vascular graft that combines adequate mechanical characteristics with sufficient biological performance. The mechanical properties of the scaffold, such as tensile strength, burst pressure, compliance, and blood permeability, are heavily influenced by its design and composition. Herein, electrospun bilayer vascular grafts are fabricated by using polycaprolactone (PCL), polylactic acid (PLA), and poly(L-lactide-co-ε-caprolactone) (PLCL) polymers. As the inner and outer layers are constructed by implementing different fiber orientations and polymer compositions, the effect of polymer selection within the inner layer and the test direction on the tensile strength and strain of the vascular prosthesis is assessed via a multilevel full factorial design approach. The results indicate that both the polymer type and the test direction, as well as their interactions, have statistically significant influences on the tensile strength and strain values