Question

RGD is a short functional peptide sequence allowing cell recognition, even selective adhesion. Now you are involved in a project to design a new synthetic vascular graft for treating patients with damaged blood vessels. To avoid the problems of thrombus formation, you propose to modify the interior surface of the graft with an immobilized adhesion ligand, a short peptide sequence (REGDVE) you just invented (REDV) for endothelial cells. The objective would be to implant the graft, and have endothelial cells from the neighboring natural vessel linings migrate into the artificial tubing, by crawling over your peptide, to line the artificial vessel with a "natural" endothelial cell lining (as shown in the schematic below). Please develop a hypothesis for your project. Design a small experiment to test your hypothesis. If the peptide is recognized by many types of integrins, what may happen in the graft? How might immobilization via physical adsorption alone affect your outcome? How might you improve the graft performance by enhancing immobilization techniques?

Answer 1

Form the given data,

a) The hypothesis is that endothelial cell recognize the REGDVE sequence as a normal adhesion ligand and crawl over the immobilized peptide of synthetic graft and become form a natural endothelial lining over synthetic graft tubing. The experiment to test the above hypothesis is that; replace the REGDVE with another peptide. Now check for whether the migration of endothelial cell takes place over synthetic graft or not.

b)

Integrins are transmembrane proteins that connect the cell to cell via extra cellular matrix (ECM). If the peptide is recognized by the many types of integrins, the endothelial cells and other cells are also binds to the synthetic graft tubing. Therefore, a thrombus formation takes place at synthetic graft, and which ultimately results inhibition of flow of blood via blood vessel.

c)

The immobilization via physical adsorption alone results formation of endothelial cell lining. This is due to specificity between the ligand and endothelial cell.