Hydrolytically degradable polymers and hydrogels made therefrom

1. A conjugate of a biologically active agent and a polyalkylene oxide-based water soluble polymer in activated form, wherein the polyalkylene oxide-based water soluble polymer comprises multiple carbonate linkages in a backbone and, for each carbonate linkage in the backbone, an oligomer linked thereto by the carbonate linkage, wherein the oligomer is branched and, prior to being linked by the carbonate linkage, has the formula:

R 3 [O—(—CHR 1 CH 2 —O—) n —] m H

where R 3 is a core branching moiety, R 1 is H, (n) can range from 2 to 2000, and m is at least 3.

2. The conjugate of claim 1 , wherein the polyalkylene oxide-based water soluble polymer in activated form corresponds to the polyalkylene oxide-based water soluble polymer having at least one end group selected from the group consisting of acryloyl, tresyl, N-succinimidyloxycarbonyl, 1-benzotriazolyloxycarbonyl, p-nitrophenyloxycarbonyl, N-maleimidyl, aldehydes, acetals, 1-imidazolylcarbonyl, vinylsulfone, iodoacetamide, and o-pyridyldithiyl.

3. The conjugate of claim 1 , wherein the polyalkylene oxide-based water soluble polymer in activated form corresponds to the polyalkylene oxide-based water soluble polymer having at least one end group selected from the group consisting of N-succinimidyl, 1-benzotriazolyl and p-nitrophenyl.

4. The conjugate of claim 3 , wherein the end group is N-succinimidyl.

5. The conjugate of claim 3 , wherein the end group is 1-benzotriazolyl.

6. The conjugate of claim 3 , wherein the end group is p-nitrophenyl.

7. The conjugate of claim 1 , wherein the biologically active agent is a peptide.

8. The conjugate of claim 1 , wherein the biologically active agent is a protein.

9. The conjugate of claim 1 , wherein (n) is 5 to 500.

10. The conjugate of claim 1 , wherein (n) is 10 to 50.