New Therapeutic Applications with Nanocarriers - Start

For entering the surrounding tissues upon intravenous application, conventional liposomes can only exit the circulation via interepithelial apertures displaying diameters of at least 150 nm. This most prominently applies to the so-called mononuclear phagocyte system (MPS), which is broadly represented in liver, spleen, bone marrow and lungs. However, while traveling the circulation liposomes are decorated with serum proteins (opsonization). As a consequence, macrophages of the MPS recognize such serum proteins via their specific surface receptors; this inevitably leads to the phagocytic elimination of protein-decorated liposomes, which thus have no realistic chance to reach other target organs in signficant quantities.

Modifying liposomal surfaces can (i) suppress the uptake and accumulation of nanoparticulate systems in the MPS; (ii) increase their systemic circulation time or half-life, respectively; and (iii) specifically address the target tissue of interest (e.g., infected tissue, malignant tumors or certain classes of immune cells). At this Department, several dissertations have been focussing on this so-called active or specific drug targeting, on its continued development and adaptation to diverse types of tissues, as well as on developing simple methods for coupling different kinds of molecules to liposomal surfaces (PhD theses by Dr. Andreas Lung, Dr. Thomas Steenpaß, Dr. Andreas Fritze, Dr. Markus Gantert, Dr. Felicitas Lewrick, Dr. Vanessa Bunjes, Ines Müller, Judith Jacoby and Daniel Molnar).