Artificial heart of Medicine of Pennsylvania State University (Penn State Hershey Medical Center) in Hershey, Pennsylvania; and AbioMed, Inc. of Danvers, Massachusetts. Despite considerable progress, the Cleveland program was discontinued after the first five years. Polymeric trileaflet valves ensure unidirectional blood flow with a low pressure gradient and good longevity. State-of-the-art transcutaneous energy transfer eliminates the need for electric wires crossing the chest wall. On July 19, 1963, E. Stanley Crawford and Domingo Liotta implanted the first clinical Left Ventricular Assist Device (LVAD) at The Methodist Hospital in Houston, Texas, in a patient who had a cardiac arrest after surgery. The patient
Human artificial chromosome resulted in a human artificial chromosome that is mitotically stable. 21HAC was also able to be transferred into cells from a variety of species (mice, chickens, humans). Using 21HAC, researchers were able to insert a herpes simplex virus- thymidine kinase coding gene into tumor cells. This "suicide gene" is required to activate many antiviral medications. These targeted tumor cells were successfully, and selectively, terminated by the antiviral drug ganciclovir in a population including healthy cells. This research opens a variety of opportunities for using HACs in gene therapy. In 2011, researchers formed a human artificial chromosome by truncating chromosome 14.