Patent ID: 8128952

Claim:
A method for defining a controlled rate of release of a first biologically active agent from a polymeric carrier matrix comprising: forming a polymeric carrier matrix; loading an amount of a first polypeptide ligand into the polymeric carrier matrix, the first polypeptide ligand having an affinity for the first biologically active agent, the first biologically active agent being a protein; and binding at least a portion of the first biologically active agent to at least a portion of the first polypeptide ligand with a reversible, non-covalent bond between the first polypeptide ligand and the first biologically active agent to form a first polypeptide ligand/first biologically active agent complex, wherein the complex is formed prior to loading the first polypeptide ligand into the polymeric matrix, the affinity of the first polypeptide ligand for the first biologically active agent being described by an equilibrium dissociation constant, K D that is defined according to the equilibrium relationship: [ C L ] ⁡ [ C D ] [ C LD ] wherein [C L ] is the concentration of the first polypeptide ligand in the polymeric carrier matrix that is not bound to first biologically active agent, [C D ] is the concentration of the first biologically active agent in the carrier matrix that is not bound to first polypeptide ligand, and [C LD ] is the concentration of the first polypeptide ligand/first biologically active agent complex in the polymeric carrier matrix; wherein the controlled rate of release of the first biologically active agent from the polymeric carrier matrix is defined by the value of the equilibrium dissociation constant.