title: Allogeneic human tissue-engineered blood vessel.
abstract: BACKGROUND
  Arterial bypass graft implantation remains the primary therapy for patients with advanced cardiovascular disease; however, there is no available synthetic small-diameter vascular graft.
  
  
  METHODS
  Tissue-engineered vessels were grown from human smooth muscle cells that were seeded on a biodegradable scaffold using a biomimetic perfusion system. The human tissue-engineered vessels (hTEV) were decellularized by a two-step process using a combination of detergents and hypertonic solutions. The mechanical characteristics were assessed by suture retention strength and burst pressure. The decellularized hTEV were implanted as aortic interpositional grafts in nude rats to evaluate in vivo performance as an arterial graft over a 6-week period.
  
  
  RESULTS
  The human tissue-engineered structure formed a vessel composed of smooth muscle cells and the extracellular matrix proteins, including collagen. After decellularization, the collagen matrix remained intact while the cellular components were removed. The mechanical strength of the hTEV after decellularization was similar to human vein in vitro, with a burst pressure of 1,567 ± 384 mm Hg (n = 3) versus 1,680 ± 307 mm Hg for human saphenous vein. The hTEVs had a high patency rate (four of five grafts) without evidence of rupture or aneurysm over a 6-week period as an aortic interpositional graft in a nude rat model. Histologic analysis showed a thin neointima with a confluent endothelium and a subendothelial layer of smooth muscle cells on the explanted tissue-engineered vessels. Transmission electron microscopy on the explanted tissue demonstrated elastin formation in the neointima and intact residual collagen fibers from the tissue-engineered vessel.
  
  
  CONCLUSIONS
  The hTEV had a high patency rate and remained mechanically stable as an aortic interpositional graft in a nude rat. The vessel supported the growth of a neointima with endothelial cells and smooth muscle cells. The host remodeling suggested the engineered matrix had a positive effect to create a regenerated vascular graft.
authors: Department of Biomedical Engineering, Yale University, New Haven, CT, USA.
authors: Clay
authors: C
authors: Quint
authors: Melissa
authors: M
authors: Arief
authors: Akihito
authors: A
authors: Muto
authors: Alan
authors: A
authors: Dardik
authors: Laura E
authors: LE
authors: Niklason
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging / Q000378:metabolism / Q000601:surgery*; D001696:Biomechanical Phenomena; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000295:instrumentation*; D002478:Cells, Cultured; D003902:Detergents / Q000737:chemistry; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D005260:Female; D006801:Humans; D006874:Hydrostatic Pressure; D006982:Hypertonic Solutions / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D009131:Muscle, Smooth, Vascular / Q000000981:diagnostic imaging / Q000378:metabolism / Q000637:transplantation*; D032389:Myocytes, Smooth Muscle / Q000378:metabolism / Q000637:transplantation* / Q000648:ultrastructure; D011475:Prosthesis Failure; D051381:Rats; D011923:Rats, Nude; D013314:Stress, Mechanical; D013536:Suture Techniques; D013997:Time Factors; D023822:Tissue Engineering / Q000379:methods; D014463:Ultrasonography; D014654:Vascular Patency; D055114:X-Ray Microtomography
chemical_list: D003902:Detergents; D016326:Extracellular Matrix Proteins; D006982:Hypertonic Solutions