Advisory: Give yourself extra time when travelling by car to Toronto General Hospital, Princess Margaret Cancer Centre, or Toronto Rehab University Centre. City of Toronto construction on University Ave. may cause delays.
At UHN, we strive to deliver Compassionate Care & Caring. Learn more about the services and supports that are available to you throughout your journey.
Our UHN programs and services are among the most advanced in the world. We have grouped our physicians,
staff, services and resources into 10 medical programs to meet the needs of our patients and help us make
the most of our resources.
At the heart of everything we do at UHN are our Healthcare Professionals. Refer a patient to one of our 12 medical programs. Learn more about the resources and opportunities available for professional growth.
University Health Network has grown to be one of the largest research and teaching hospital networks in Canada - pioneers in improving the lives of patients. Our long history of health professions education at Toronto General, Toronto Western, Princess Margaret and Toronto Rehab hospitals has consistently advanced the science of education.
University Health Network is a health care and medical research organization in
Toronto, Ontario, Canada. The scope of research and complexity of cases at UHN has made us a national and international
source for discovery, education and patient care.
Being touched by illness affects us in different ways. Many people want to give back to the community
and help others. At UHN, we welcome your contribution and offer different ways you can help so you can find one that suits you.
The Newsroom is the source for media looking for information about UHN or trying to connect with one
of our experts for an interview. It's also the place to find UHN media policies and catch up on our news stories, videos, media releases,
podcasts and more.
You are looking at a strip of muscle, about the size of a grain of rice, suspended between two very fine wires. Despite its cylindrical shape, it is a miniature version of the human heart, and contracts and relaxes with the same hypnotic rhythm.
This feat was achieved by a team of researchers led by Drs.
Milica Radisic and
Peter Backx, Senior Scientists at the Toronto General Hospital Research Institute. Because their miniature heart closely mimics the cells found in a real heart, it may be a game changer in the study of heart disease and the search for therapeutic drugs.
The human heart has two types of chambers – atria and ventricles – that have different functions and are made of different kinds of cells. Because of this, atrial cells, which make up atria, and ventricular cells, which make up ventricles, respond to drugs differently.
While abnormal beating of the atria is the most common heart defect implicated in heart failure, up until recently, researchers had only been able to make ventricular tissues from human pluripotent stem cells.
The breakthrough platform engineered by Dr. Radisic and her colleagues, named Biowire II, is capable of growing both atrial and ventricular tissues. These atrio-ventricular Biowires have atrial cells on one end and ventricular cells on the other end, and have the same mechanical properties as real heart tissue.
"Biowires grown from the cells of healthy hearts are distinct from those grown from the cells of abnormal hearts," describes Dr. Radisic. "This enables us to model various heart conditions in the lab."
The Biowires also captured the effect of the drug ranolazine on the heart. Ranolazine is currently used to treat chest pain caused by insufficient blood supply to the heart.
With engineered tissues that resemble real hearts such as the Biowire II, researchers are one step closer to understanding the progression of heart disease and developing drugs that target specific heart cells without harming others.
This work was supported by the Canadian Institutes of Health Research, the Natural Sciences and Engineering Research Council of Canada, the U.S. National Institutes of Health, the Ted Rogers Centre of Heart Research, and the Toronto General & Western Hospital Foundation. Dr. Brian Cox holds a Tier 2 Canada Research Chair (CRC) in Placental Development and Maternal-Fetal Health. Dr. Gordon M. Keller holds a Tier 1 CRC in Embryonic Stem Cell Biology. Dr. Peter H. Backx holds a Tier 1 CRC in Cardiovascular Biology. Dr. Milica Radisic holds a Tier 2 CRC in Functional Cardiovascular Tissue Engineering.