| abstract |
The present invention relates to a highly efficient method of preparing modified microcapsules exhibiting selective targeting. These microcapsules are suitable for encapsulation or surface attachment of therapeutic and diagnostic agents. In one aspect of the invention, surface charge of the polymeric material is altered by conjugation of an amino acid ester to the polymer, providing improved targeting of encapsulated agents to specific tissue cells. Examples include encapsulation of hydrophilic radiodiagnostic agents in 1 νm capsules to provide improved opacification and encapsulation of cytotoxic agents in 100 νm capsules for chemoembolization procedures. The microcapsules are suitable for attachment of a wide range of targeting agents, including antibodies, steroids and drugs, which may be attached to the microcapsule polymer before or after formation of suitably sized microcapsules. The invention also includes hydrophilic microcapsules surface modified with hydroxyl groups. Various agents such as estrone may be attached to the microcapsules and effectively targeted to selected organs. |