(50e) Improving the Biocompatibility of Expanded Polytetrafluoroethylene Vascular Graft Via a Novel Biodegradable Elastomer

Currently, there are no synthetic vascular grafts available that exhibit long-term patency for the replacement of small diameter blood vessels. In the present study, we propose the use of a biodegradable polyester elastomer, poly(1,8-octanediol citrate) (POC) [1,2] that is based on citric acid to engineer the lumen of ePTFE grafts via a simple spin-shearing method followed by interfacial in-situ polycondensation. [3] We demonstrated successful surface modification of ePTFE grafts without affecting graft compliance. POC-modified ePTFE has reduced thrombogenicity and enhanced endothelial progenitor cell compatibility relative to unmodified ePTFE grafts in vitro. In a porcine iliac artery ePTFE bypass model, the POC-modification conferred reduced thrombogenicity and macrophage infiltration into the ePTFE grafts in vivo. [3] Therefore, the materials-based approach described in this study represents a paradigm shift and a new starting point towards engineering a functional vascular graft for small diameter blood vessel replacement. Future studies will evaluate whether a tissue-engineered endothelium using a POC-ePTFE graft reduces clotting incidents and improves long-term patency in vivo.

References 1. Jian Yang, Antonio Webb, Guillermo Ameer. Novel citric acid-based biodegradable elastomers for tissue engineering. Advanced Materials 2004,16(6):511-516. 2. Jian Yang, Antonio R. Webb, Samuel J. Pickerill, Gretchen Hageman, Guillermo A. Ameer. Synthesis and evaluation of poly(diol citrates) biodegradable elastomer. Biomaterials 2006,27: 1889-1898. 3. Jian Yang, Delara Motlagh, Josephine B. Allen, Antonio R. Webb, Melina R. Kibbe, Oliver Aalami, Muneera Kapadia, Timothy J. Carroll, Guillermo A. Ameer. Modulating ePTFE vascular graft host response via citric-acid based biodegradable elastomers. Advanced Materials 2006 (in press)