Heart, Lung, and vascular registries: Evolving goals, successful approaches, and ongoing innovation

Cardiolog

Linear Shear Conditioning Improves Vascular Graft Retention of Adipose-Derived Stem Cells by Upregulation of the α5β1 Integrin

Use of adult adipose-derived stem cells (ASCs) as endothelial cell substitutes in vascular tissue engineering is attractive because of their availability. However, when seeded onto decellularized vascular scaffolding and exposed to physiological fluid shear force, ASCs are physically separated from the graft lumen. Herein we have investigated methods of increasing initial ASC attachment using luminal precoats and a novel protocol for the gradual introduction of shear stress to optimize ASC retention. Fibronectin coating of the graft lumen increased ASC attachment by nearly sixfold compared with negative controls. Gradual introduction of near physiological fluid shear stress using a novel bioreactor whereby flow rate was increased every second at a rate of 1.5 dynes/cm2 per day resulted in complete luminal coverage compared with near complete cell loss following conventional daily abrupt increases. An upregulation of the α5β1 integrin was evinced following exposure to shear stress, which accounts for the observed increase in ASC retention on the graft lumen. These results indicated a novel method for seeding, conditioning, and retaining of adult stem cells on a decellularized vein scaffold within a high-shear stress microenvironment