Liposome Coated Stents: A Method to Deliver Drugs to the Site of Action and Improve Stent Blood-Compatibility

Abstract

A method to correct stent related complications non-invasively, is the local delivery of therapeutic agents. Different drugs have been delivered on stents, after being either dispersed or encapsulated in polymeric materials, and placed on stents to form drug-eluting-stents (DE-stents). Investigation of possibility to cover polymer - coated metallic stents, with liposomal drugs, for preparation of novel DE-liposome-coated-stents, has been initiated few years ago. In this context our research has been focused on answering the following questions: (i) Can liposomes be applied as coatings on polymer covered stents? (ii) Can drug release from liposome coated-stents be controlled? And: (iii) how is haemo-compatibility of stents affected? The results of the experiments carried out demonstrate that liposomal formulations of drugs can be used as coating systems of polymer covered stents for achieving sustained release of drugs at the site of interest. By modifying liposome characteristics, different amounts of drugs may be placed on the stents and their release rates can be adjusted for maximum therapeutic benefit. Finally, haemocompatibility of stents is highly improved (mainly in terms of cell adhesion and activation of coagulation system), when stents are coated with heparin-encapsulating -DRV liposomes.

Keywords: :

• stent
• liposome
• heparin
• controlled release
• dexamethasone
• haemocompatibility