Vascularisation of tissue-engineered grafts: the regulation of angiogenesis in reconstructive surgery and in disease states

Angiogenesis (the formation of new blood vessels) is essential for the growth of new tissue, tissue repair and wound healing. Tissue engineering, the 'construction of new tissue and organs for reparative purposes, relies on angiogenesis for the vascularisation of these new grafts. In tissue engineering, the emphasis to date has been on vascularisation of newly constructed tissue grafts by an extrinsic blood supply, and relatively little attention has been given to the possibility of building these grafts around an intrinsic blood supply. However, there are many disease processes, notably tumour growth, where excess angiogenesis can be a major problem. The purposes of this review are, first, to examine various methods of vascularising tissue-engineered grafts, and, second, to compare the role of angiogenesis in tissue engineering, where stimulation of angiogenesis is paramount, with pathological states, such as tumour growth, where angiogenesis needs to be inhibited. (C) 2002 The British Association of Plastic Surgeons. Published by Elsevier Science Ltd. All rights reserved.