Preparation and characterization of immunoliposomes directed against metastatic cancer

Abstract

The clinical efficacy of conventional chemotherapeutics is limited due to poor pharmacokinetics of the drugs, limited systemic circulation lifetime, undesirable bio-distribution, and non-specific cellular uptake. The inability to deliver the therapeutic drug specifically to the target tissues results in severe and harmful toxic effects on normal organs and tissues. Thus, site specific delivery of anti-cancer therapeutics is an area actively being explored. One of the most promising platforms to achieve this is through the use of liposomal technology. Liposomes are lipid bilayer vesicles which can be used for encapsulation of a diverse array of biomolecules as well as synthetic drug molecules. Various liposomal drugs have even been commercialized. In addition to drug encapsulation, liposomes offer the advantage of being amenable for site-specific delivery by modification of their surface with various types of ligands such as peptides, carbohydrates and antibody fragments against antigens that are over-expressed on the surface of cancer cells. Due to their high specificity, antibodies have proven to be the most potential ligands for site specific delivery of liposomal drugs. Such liposomes conjugated with antibodies or their fragments are referred to as immunoliposomes. This study aims to explore the possibility of creating immunoliposomes with a therapeutic antibody targeted against metastatic cancers. The approach used includes digesting the antibody to generate different fragments and conjugating the appropriate fragment with functionalized liposomes followed by characterization of immunoliposomes for their structural and functional properties.