The present invention relates to a highly efficient method of preparing modified microcapsules exhibiting selective targeting. These microcapsules are suitable for encapsulation 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 providing improved targeting of encapsulated agents to specific tissue cells. Examples include encapsulation of radiodiagnostic agents in 1 .mu.m capsules to provide improved opacification and encapsulation of cytotoxic agents in 100 .mu.m 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 microcapsules surface modified with hydroxyl groups. Various agents such as estrone may be attached to the microcapsules and effectively targeted to selected organs.
本发明涉及一种高效制备改性微囊的方法,这些微囊表现出选择性靶向性。这些微囊适用于包封治疗和诊断剂的表面附着。在本发明的一个方面中,通过共轭
氨基酸酯改变聚合物材料的表面电荷,从而提高了包封剂对特定组织细胞的靶向性。例如,在1微米的囊泡中包封放射诊断剂以提供改善的显影度,在100微米的囊泡中包封细胞毒性剂用于
化学栓塞手术。这些微囊适用于附着各种靶向剂,包括
抗体、类
固醇和药物,这些剂可以在形成适当大小的微囊之前或之后附着到微囊聚合物上。本发明还包括表面改性羟基囊。各种剂,如
雌酮,可以附着到微囊上并有效地靶向到选定的器官。