Journal de science et d'ingénierie tissulaires

Endothelial Cell Lining of PET Vascular Prostheses: Modification with Degradable Polyester-based Copolymers and Adhesive Protein Multi-layers

Abstract

Jaroslav Chlupac, Elena Filova, Tomas Riedel, Eduard Brynda, Elzbieta Pamula and Lucie Bacakova

Background: Bypass surgery for atherosclerosis is confronted with the absence of endothelial cells in the lumen of vascular prosthesis in humans. This imposes a risk of thrombosis. New biomaterials try to minimize surface thrombogenicity.

Methods: Knitted polyethylene terephthalate (PET) vascular graft patches were impregnated with degradable polyester polymers: poly (L-lactide-co-glycolide) (PLG) or poly (L-lactide-co-glycolide-co-ε-caprolactone) (PLGC). The luminal surface was coated with collagen type I (Co) to which extracellular matrix proteins laminin (LM), fibronectin (FN), or surface fibrin gel (Fb) were attached. Three types of prostheses (PET, PET–PLG and PET– PLGC) and 5 types of protein assemblies (+Co, +Co/LM, +Co/FN, +Co/Fb, +Co/Fb/FN) were fabricated. Scanning electron microscopy and measurements of the water contact angles were performed. The development of a bovine endothelial cell layer was studied in a static culture for 1 week.

Results: The cells reached confluence on all PET surfaces with the highest final density on +Co/FN. Impregnation of PET with polymers made it less adhesive for cells in the following order: PET > PET–PLG > PET– PLGC. However, additional coating with the protein assemblies enhanced the endothelial cell growth, especially on fibrin-containing surfaces.

Conclusion: Tri-component vascular grafts composed of PET, copolymers and cell-adhesive assemblies were fabricated. The endothelial lining on the polymer-coated grafts was promoted after modification with the protein multilayers.
Artificial vascular prostheses have been made of non-degradable, non-compliant and thrombogenic materials for more than 50 years. Thus, they resemble passive tubing. Potential bio-activation by degradable materials and by introduction of living endothelial cells may approximate these materials to native artery. This work provided a method to include bio-degradable polymers into vascular graft and to facilitate the growth of cell lining via adhesive protein multilayers.