The research efforts are focused on the connexins of cardiac myocytes and vascular smooth muscle cells. They are all thought to be essential to processes such as developed vaso-motor tone and cardiac arrhythmias. A variety of methods are used to monitor permselectivity and gating of homotypic, heterotypic and heteromeric forms. We are also interested in delineating the integration of exogenously placed stem cells into tissues and role gap junction channels play. To assist us in defining the types of connexins expressed in tissue we use both immuno-staining and Western blotting.Since his initial observations he has characterized the gating of gap junction channels as well as their permselectivity to higher molecular weight substances. Recently he has demonstrated that small interfering RNA, a molecule of 4 kD, can permeate gap junctions and silence expression of target proteins in electrically connected cells. In 2003 he began his research studies on gap junction channels in human mesenchymal stem cells, in collaboration with Drs. Ira Cohen, Mike Rosen and Richard Robinson, where he demonstrated they expressed and trafficked both connexin43 and connexin40 and made gap junctions with cardiac myocytes. He also has been active in studies of stem cell homing and stem cells as the delivery system for creating a biological pacemaker. In 2009 he oversaw a project that used hMSCs to carry pacemaker genes to isolated canine ventricular myocytes demonstrating that the two cell functional syncytium was a biological pacemaker.