Selective Interactions Of Concanavalin A-Modified Tetraether Lipid Liposomes

For the development of site specific liposomes, high stability and long circulation properties are very promising for the improvement of drug targeting and drug delivery system as well as improvement of bioavailability of efficient bioactive drugs. Tetraether lipids (TELs) are very stabile lipids, extracted from Thermoplasma acidophilum. Because of its high chemical stability and its biocompatibility, Tetraether lipid liposomes prepared with TELs are excellent candidates for liposomal drug delivery. In this study a model protein, Concanavalin A (ConA) was chosen for a simulation of a specific adsorbtion onto mannan surface. Concanavalin A (ConA) is a lectin, extracted from Canavalia ensiformis, which interacts with sugar domains localized on inflammatory active tissues or tumors. In this study, stable TEL liposomes were prepared and characterized. Furthermore to develop side specific liposomes, tetraether lipids were activated and, ConA was covalently bond onto the surface of the prepared liposomes. Interaction of ConA conjugated liposomes with mannan-modified surfaces was investigated by Biomolecular Interaction Analysis (BIA) via Reflectometric Interference Spectroscopy (RIfS). This provides real time observation of interactions between carbohydrate structure and TEL liposomes. Specific interaction was also visualised by AFM imaging subsequent to the RIfS measurements. According to the results, with ConA conjugated liposomes, high specific adsorption efficiency was observed. Consequently, this specific adsorption assay between ConA and mannan surface can be considered as a model for the further studies utilized with specific biomarkers for a selective active agent transfer to tumors and inflammatory active tissues. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim