Controlled Release of Antiretroviral Drugs

The treatment of AIDS using combinations of antiretroviral drugs has highly reduced the HIV-1 related morbidity and mortality, provided that the plasma viral load can be maintained as low as possible. However, eradication of the virus does not seem attainable with the present strategies of interventions which is due to two major obstacles: If resistant mutations appear the virus will escape further treatment, and latent virus reservoirs exist which cannot be reached with the current treatment regimens. One of these sanctuaries is the mononuclear phagocyte system (MPS) with its HIV-1 target cells, such as monocytes/ macrophages (MO/MAC), dendritic cells (DC) and Langerhans cells which can be considered as primary cells for viral entry, and subsequently are responsible for distribution of the virus throughout the organism into various tissues. Colloidal drug carriers are easily phagocytosed by MO/MAK. Therefore, they can facilitate the uptake of antiviral drugs by these cells and may enable a considerably improved AIDS therapy. The present article summarises strategies which allow the targeting of antiviral drugs to these cells by the use of carrier systems including nanoparticles, liposomes, immunoliposomes or red blood cells.