Development and evaluation of elastomeric hollow fiber membranes as small diameter vascular graft substitutes.

Engineering of small diameter (<6mm) vascular grafts (SDVGs) for clinical use remains a significant challenge. Here, elastomeric polyester urethane (PEU)-based hollow fiber membranes (HFMs) are presented as an SDVG candidate to target the limitations of current technologies and improve tissue engineering designs. HFMs are fabricated by a simple phase inversion method. HFM dimensions are tailored through adjustments to fabrication parameters. The walls of HFMs are highly porous. The HFMs are very elastic, with moduli ranging from 1-4MPa, strengths from 1-5MPa, and max strains from 300-500%. Permeability of the HFMs varies from 0.5-3.5×10(-6)cm/s, while burst pressure varies from 25 to 35psi. The suture retention forces of HFMs are in the range of 0.8 to 1.2N. These properties match those of blood vessels. A slow degradation profile is observed for all HFMs, with 71 to 78% of the original mass remaining after 8weeks, providing a suitable profile for potential cellular incorporation and tissue replacement. Both human endothelial cells and human mesenchymal stem cells proliferate well in the presence of HFMs up to 7days. These results demonstrate a promising customizable PEU HFMs for small diameter vascular repair and tissue engineering applications.