Drug elution form porous ceramic components for threshold reduction in pacemaker applications

Abstract

The implantation of heart pacemakers results in an inflammatory response in cardiac tissue which makes the electrode/tissue interface less favourable for energy transfer to the cardiac muscle, and increases the threshold voltage required to pace the heart. Minute porous alumina ceramic components with a tightly controlled bimodal pore size distribution have been developed to deliver a tiny amount of anti-inflammatory steroid right near the electrode/tissue interface. The pore structure, consisting of a 30% volume fraction of 7μm pores and a 30% volume fraction of 50-7Oμm pores is impregnated with dexamethasone sodium phosphate, which elutes slowly into the tissue near the interface. This device has been shown to be highly effective in reducing the threshold voltage in sheep.