Electrospun vascular graft properties following femtosecond laser ablation

Abstract

For polymers in tissue engineering to reach their full potential, the three-dimensional integration of cells with scaffolds must become more complex. In vascular grafts this is particularly challenging as specific physical property requirements must be met. We apply a combination of polymer processing techniques-electrospinning and femtosecond laser ablation-to produce microchannels inside the walls of electrospun tubes providing for spatially-controlled cell seeding. To determine if such a scaffold can provide the desired physical properties, a greater understanding of the relationship between manufacturing and mechanics is needed. As the strength of these scaffolds is an important functional component, the relative properties of single, bi- and tri-layer combinations produced using different solvents were compared. The effect of fiber layer thickness was also investigated. The thickness of the hexafluorisopropanol-derived layer dominated the overall scaffold properties regardless of the nature of the other two layers. Although laser-machined microchannels had substantial effects on single layer and some of the bilayers, in the "final" trilayer scaffold, little effect on mechanical properties was observed. The concept of "vascular wall engineering" could successfully produce trilayer composite scaffolds that maintain the targeted mechanical properties while allowing intricate, three-dimensional cell seeding. © 2011 Wiley Periodicals, Inc.