Transformation of nonvascular acellular tissue matrices into durable vascular conduits

Crosslinking of saphenous vein ECM by procyanidins for small diameter blood vessel replacement

“…2,8 GA-crosslinking can partly overcome these shortcomings and satisfy the basic requirements of a small-diameter vascular substitute; however, at the same time, GA-croslinking induces the calcification of ECMs and leads to cytotoxic effect on the repopulation of ECMs due to slow release of GA. 8,[22][23][24] In this study, the svECM substitutes were prepared by decellularized saphenous vein. After PC-crosslinking, the svECM substitutes displayed tubular configuration and improved mechanical properties, cytocompatibility, immunogenicity, antithrombosis potential, calcification resistance, and chemical stability.…”

Randomized clinical trial comparing decellularized bovine ureter with expanded polytetrafluoroethylene for vascular access

“…The reduction in thrombotic events after 9 months may relate to the anticipated host remodelling of these biological grafts 9,10 . This process is analogous to the time required for arterialization of autologous vein grafts used as arterial replacement 19 .…”

“…Sequential treatment by hypotonic lysis, nuclease (deoxyribonuclease and ribonuclease) digestion and isotonic washout gently removes the cellular components of the ureter while preserving its collagen matrix, allowing implantation of this xenograft without immunosuppression. Unlike other biological grafts, the SG 100 is not chemically cross-linked, nor does it contain any external support, potentially permitting ingrowth of host cells into the matrix 9,10 . Mechanically, it is compliant and has dimensions suitable for anastomoses to upper arm vessels.…”

Tissue engineering of vascular conduits

“…It seems that, if tissue-engineered blood vessels are to be a viable and durable vascular conduit in vivo, a confluent endothelium is an important prerequisite. Previous non-endothelialized implants of decellularized biological conduits in animal models produced moderately acceptable patency rates when placed in sites of either high flow or low resistance, or both 15,19,20,22,23 . In one animal study 21 , small intestinal submucosa was implanted as a small-diameter vascular graft in high-flow anastomoses involving carotid and femoral arteries; all animals received warfarin and aspirin for up to 8 weeks after surgery.…”

“…Chemical methods aim to produce native cell lysis, detergent removal of cell membrane lipids and removal of nuclear debris, which can stimulate calcification and graft degeneration. They involve a combination of enzymatic and detergent treatments, including trypsin-EDTA, hypotonic Tris buffer, sodium dodecyl sulphate and nucleases 14,15,20,27 . Mechanical methods involve eversion and surface abrasion of harvested tissue to produce an acellular layer composed primarily of type 1 collagen 19,24 .…”