The endothelium is involved in a number of normal physiological processes (regulating circulating levels of vasoactive agents, blood/gas exchange, regulating cellular traffic between intavascular and extravascular compartments of tissues, maintenance of the blood brain barrier, and so forth) and pathophysiological conditions characterized either by increased angiogenesis (arthritis, diabetic retinopathy, atherosclerosis, tumor growth, and metastasis) or inadequate angiogenesis [failure of ulcers to heal (inadequate wound healing in general), myocardial infarction, limb ischaemia secondary to arterial occlusive diseases and others]. Its location immediately adjacent to the blood stream and the fact that it has a large surface area makes it an attractive target for genetransfer/gene-therapy strategies.
