Patent ID: 7374778

Claim:
A method for delivering a therapeutic or diagnostic agent to a cell, comprising: (a) treating a cell with a transport agent and a therapeutic or diagnostic agent, wherein the transport agent and therapeutic or diagnostic agent are taken into the cell by endocytosis to provide an endosome having an endosomal membrane and containing the transport agent and therapeutic or diagnostic agent, wherein the transport agent is effective in disrupting the endosomal membrane, wherein the therapeutic or diagnostic agent is covalently coupled to the transport agent, and wherein the transport agent is a poly(alkylacrylic acid) selected from the group consisting of poly(ethylacrylic acid), poly(propylacrylic acid), poly(butylacrylic acid), and mixtures thereof; and (b) releasing the therapeutic or diagnostic agent from the endosome into the cell cytoplasm by the action of the transport agent on the endosomal membrane.