Poly lactic acid based scaffolds as graft for small-diameter arterial replacement.

Vascular Tissue engineering (VTE) has emerged as a promising approach to develop blood vessel substitutes. Investigators have explored the use of arterial tissue cells combined with various types of natural and synthetic scaffolds to make tubular constructs in order to develop a functional small-diameter arterial replacement graft. The grafts must mimic the unique viscoelastic nature of an artery and be non-disruptive to blood ?ow. Moreover, after implantation, the scaffold must be gradually populated by cells and replaced by extra cellular matrix; with this respect, it is crucial that this replacement takes place with a well-defined timescale. In this work tubular scaffolds for VTE were produced via Diffusion Induced Phase Separation. Several PLA/ PLLA blends (100/0, 90/10, 75/25 wt/wt) were utilized in order to tune the crystallinity of the scaffolds and thus the rate of biodegrada- tion. In-Vitro biological tests were carried out in order to estimate the non-cytotoxicity of the scaffolds and endothelial cell proliferation inside them. The results showed that the scaffolds present an open structure across the thickness of their walls, a high level of porosity (over 70%) and a homogeneous internal surface with micropores 1– 2 lm large. Biological tests showed that scaffold do not induce cell tox- icity; cells are able to grow and proliferate into the scaffold covering its internal surface, so they can be considered suitable for the application for the designed aimed.