Tissue Engineering of Small Diameter Cardiovascular GraftsAuthor(s): Uma Maheshwari Subramanian and Abhilash M
To design a biocompatible, nonthrombogenic, compliant, infection resistant and technically facile small diameter vascular graft is a surmounting feat to achieve. A whole host of biological grafts and synthetic prostheses are available. Saphenous vein and internal mammary artery grafts were initially used for coronary artery bypass grafting (CABG). Clinical efficiency of synthetic, allogenic or xenogenic graft is limited by thrombosis, rejection, chronic infection and poor mechanical properties. Commonly used synthetic grafts like ePTFE and Dacron (PET) are limited by thrombogenicity, neointimal hyperplasia and low patency rate. New surface processing techniques such as glutaraldehyde fixation, treatment with polyepoxy compounds and dye mediated photo oxidation improves the patency rates and reduces immunogenicity but has its own disadvantages like increased tissue calcification and cytotoxicity. Tissue engineering offers an alternative, in which endothelial cells are seeded on either decellularized arteries or polymeric nanofibrous scaffolds which are prepared by non woven electro spinning technology. This technique improves graft patency. The surface of the polymer scaffold could be modified using peptides like Arginine-Glycine-Asparate (RGD), heparin or treated with recombinant type VIII collagen for better endothelial cell (EC) attachment and retention. Advancing scaffold technology in collaboration with biological, chemical and materials science engineering will lead to the design of ideal cardiovascular graft. This article reviews the current strategies that are employed clinically to treat blocked blood vessels and the importance of tissue engineering of small diameter arteries.