| 摘要 |
<p>Thermally reversible polyurethane hydrogels are formed by adding water to a gel forming hydrophilic polyurethane polymer produced by reacting under anhydrous conditions an organic diisocyanate with a glycol component in an NCO/OH mole ratio of from about 0.5/1 to about 1/1 wherein the percentage by weight of the diisocyanate in the reaction mixture is from about 2 % to about 25 %. The hydrogels are solids at room temperature but liquify at higher temperatures such as body temperature and therefore are useful as carriers for the protection, delivery and sustained release of a variety of active agents including pharmaceuticals, cosmetics, living cells and organisms.</p> |
