Poly(amido-amine)s carrying primary amino groups as side substituents

Poly(amido-amine)s carrying primary amino groups as side substituents have been obtained by polyaddition of N-triphenylmethyl monosubstituted 1,2-diaminoethane (TPHMAE) to 2,2-bisacrylamide acetic acid or 1,4-bisacryloylpiperazine and subsequent removal of the protecting triphenylmethyl group by treating the resultant polymers with aqueous hydrochloric acid. Soluble polymers can be also obtained directly by the polyaddition of monoprotonated 1,2-diaminoethane to 2,2-bisacrylamide acetic acid in the presence of a limited amount of added acetic or hydrochloric acid. The resultant polymers are of a higher molecular weight than the corresponding ones prepared from TPHMAE. By adding a limited amount of N-triphenyl-methyl-monosubstituted 1,2-diaminoethane to the monomer mixtures leading to poly(amido-amine)s with a recognised potential as nonviral vectors, such as ISA 23 and ISA 1, a controlled number of pendant primary amino groups have been introduced. By this procedure, ISA 23 and ISA 1 become suitable as polymer carriers for carboxylated drugs as well as amendable to the labelling techniques by fluorescent probes commonly employed for proteins.