An angiogenic agent or an anti-angiogenic agent comprising a thyroid hormone or analog thereof that binds to the cell surface receptor for thyroid hormone on integrin αvß3, wherein said thyroid hormone or analog thereof is selected front the group consisting of levothyroxine (T4), triiodothyronine (T3), 3, 5-dimethyl-4- (4-hydroy-3-isopropylbenzyl)- phenoxy acetic acid (GC1), 3,5-diiodothyropropionic acid (DITPA), tetraiodothyroacetic acid (TETRAC), and triiodothyroacetic acid (TRIAC) conjugated to a polymer via a covalent bond, wherein said polymer is polyvinyl alcohl, acrylic acid ethylene co-polymer, polyethylene glycol (PEG), polylactic acid, polyglycolide, polylactide, agarose, or co-polymers thereof and wherein the angiogenic agent acts at the cell membrane level and has pro-angiogenic properties independent of the nuclear thyroid hormone receptor effects or wherein the anti-angiogenic agent acts at the cell membrane level to inhibit pro-angiogenesis agents.
