Patent ID: 8524214

Claim:
A conjugate of Formula (I): wherein Polyal is a polyacetal or polyketal; Linker is a dicarboxylic acid moiety containing two or more atoms between the carbonyls and represents the two or more atoms between the carbonyl groups; R 1 is H or CH 3 ; R 2 is —CH(Y)—C(O)—, wherein Y is a non-hydrogen side chain of a naturally occurring amino acid; or Tether is alanine, β-alanine, sarcosine, or proline; and Drug is any organic compound with a molecular weight of between about 200 daltons and 1000 daltons, capable of covalent attachment to Tether; wherein when Linker is a dicarboxylic acid with two atoms between the carbonyls and Tether contains a nitrogen with no reactive hydrogen, the release half-life of Drug is from about 10 h to more than about 300 h; when Linker is a dicarboxylic acid with at least three atoms between the carbonyls and contains a heteroatom alpha to the carbonyl forming the ester, the release half-life is less than about 10 hours; when Linker is a dicarboxylic acid with at least three atoms between the carbonyls with no heteroatom alpha to the carbonyl forming the ester, the release half-life is more than about 100 hours; when Linker is a dicarboxylic acid with two atoms between the carbonyls and Tether contains a nitrogen with a reactive hydrogen the release half-life of Drug is from about 0.1 hours to about 24 hours; and wherein the release half-life being measured in 0.05M phosphate buffer, 0.9% saline, pH 7.4, at 37° C.