Endothelial cell-seeding decellularized vein transplants: A novel arterial bypass conduit

Abstract

Listen

Translate article

Introduction. We investigate vein transplants decellularized with sodium dodecyl sulfate (SDS) as vascular tissue-engineering scaffolds. We hypothesize that these scaffolds remain intact until repopulated with autologous cells, cause nominal immunologic response, and provide a satisfactory luminal surface for endothelial cell seeding prior to implantation. Methods. In vivo study of the scaffold involved carotid interposition grafting in canines ( n = 16). Grafts were evaluated biweekly with duplex ultrasound and explanted (2 weeks, 2 months) for gross, histological, and immunohistochemical examination. In vitro study involved seeding scaffolds with endothelial cells (ECs). Alteration in attachment time (30, 60, 120 min) and matrix precoating (fetal bovine serum, FBS) were investigated. Cell attachment was measured by cell count, DNA content analysis, and scanning microscopy. Results. Vein graft diameter at implantation (7.4 ± 0.7 mm) remained stable over 2 months (8.9 ± 1.7 and 6.5 ± 1.6 mm for autograft and decellularized allografts, respectively). Decellularized allografts showed reduced intimal hyperplasia and inflammatory infiltrate. Transmural repopulation of the scaffold was seen by 2 months postimplantation. Luminal thrombus was also seen, resulting in reduced patency compared with autografts (13/16 versus16/16 patent). Seeding studies demonstrated EC attachment at 30 min, with progressive improvement at 1 and 2 h (47, 72, and 89% attachment, respectively). DNA content analysis confirmed similar increases over time (155, 227, 245ηg/ml). Pre-coating with FBS significantly increased attachment. Scanning microscopy revealed both attachment and spreading of ECs on the luminal surface of decellularized vein by 2 h. Conclusion. Decellularized vein transplants remain strong in vivo and demonstrate reduced vascular rejection; however, they may be thrombogenic due to loss of their luminal endothelium. Luminal EC seeding of these transplants can be achieved in vitro, with near confluent attachment as early as 2 h following seeding. This technique may prove useful in improving the efficacy of decellularized vein transplants as arterial bypass grafts.