Targeting of antiviral drugs bound to protein carriers.

The value of antiviral drugs would be improved by their selective delivery into infected cells. This goal can be achieved by conjugating the drug to a protein which is taken up specifically by the cells where the virus grows. Conjugates will be pharmacologically effective in these cells if the bond linking the drug to the carrier does not suppress the activity of the drug or if the bond is broken down with consequent intracellular release of the drug. Experiments on this approach to antiviral chemotherapy have been directed mainly at selectively delivering antiviral agents into hepatocytes in order to increase their chemotherapeutic index in the treatment of chronic hepatitis B.