Patent ID: 8017739

Claim:
A method for preparing a conjugate comprising an oxidized protein and a hydroxyalkyl starch (HAS) polymer derivative, the method comprising reacting at least one functional group A of the polymer derivative with at least one functional group Z of the oxidized protein and thereby forming a covalent linkage, wherein Z is an aldehyde group or a keto group, wherein A comprises an amino group forming said linkage with Z, wherein the protein is selected from the group consisting of IFN beta, GM-CSF, APC, tPA, A1AT, AT III, factor VII, factor VIII, and factor IX, wherein the oxidized protein comprises an oxidized carbohydrate side chain or an oxidized N-terminal group or an oxidized carbohydrate side chain and an oxidized N-terminal group, and the aldehyde group or the keto group Z of the oxidized protein is located in the oxidized carbohydrate side chain or at the oxidized N-terminal group or in the oxidized carbohydrate side chain and at the oxidized N-terminal group, and wherein the HAS polymer comprises a reducing end that is not oxidized, and the polymer derivative is formed by reacting the polymer at its non-oxidized reducing end with an at least bifunctional linking compound that comprises the functional group A or a functional group that is chemically modified to give functional group A.