Vascular graft endothelization: a way towards improved hemocompatibility?

Background

Endothelial cells (ECs) present in the lining of healthy blood vessels are known for their role inhibiting platelet aggregation and fibrin formation, allowing the continuous flow of blood. Therefore, the swift and effective endothelisation of grafts has been suggested as a possible method of preventing the thrombotic and inflammatory response often seen early in synthetic scaffolds for vascular access. However, this anti-thrombotic ability is dependent on specific local hemodynamic conditions and on the extracellular environment. It has been recently shown that certain fibrous topographies can promote endothelial migration and proliferation, through loss of endothelial cell-cell junction organization and increased cytoskeletal contractility. Nevertheless, a link between such different substrate topographies and the pro/anti-thrombotic phenotype of ECs is yet to be elucidated. Such findings would greatly benefit the future design of electrospun vascular grafts by improving their hemocompatibility.

Objective

The aim of this project is to characterize the growth dynamics and phenotype of ECs seeded on novel electrospun materials with different microscopic structures and their respective anti-thrombotic potential. Specifically, the following aspects will be evaluated:

1. Cell morphology and expression of structural endothelial markers;
2. Cell proliferation;
3. Expression of genes involved in platelet adhesion/activation and blood coagulation.

Methods and project outline

During the execution of this project, students will have the opportunity to learn a range of experimental techniques, such as: 

1. Electrospinning of scaffolds and respective characterization by electron microscopy;
2. Assessment of cellular proliferation using metabolic and dsDNA quantification assays;
3. Morphological and phenotypical characterization of ECs by immunofluorescence;
4. Detection of thrombosis-related proteins in ECs by western blot.