Disclosed is a thermogelling biodegradable aqueous polymer solution useful in providing a bioactive agent delivery system. A thermogelling biodegradable aqueous polymer solution may comprise a biocompatible block and a biodegradable polypeptide block, where the blocks are linked to form a polymer of a general structure comprising the formula of C.sub.nD.sub.m, wherein n is equal to or greater than 1, m is equal to or greater than 1, C is a biodegradable polypeptide block, and D is a biocompatible soluble polymer having a chain length such that if D is not biodegradable, D may be eliminated through a glomeruli filtration system.