Dr. Ren-Ke Li, MD, PhD

Principal Investigator, Ren-Ke Li Laboratory

Dr. Ren-Ke Li, MD, PhD is a Senior Scientist at the Toronto General Hospital Research Institute, University Health Network and a Professor of Medicine in the Department of Surgery, Division of Cardiac Surgery at the University of Toronto.

Dr. Li obtained his M.D. from Harbin Medical University in China and his Ph.D. in Clinical Biochemistry from the University of Toronto. He became an Assistant Professor at the University of Toronto in 1993 and was promoted to Full Professor in 2002. He is the recipient of the Canada Research Chair in Cardiac Regeneration (Tier 1) of the Canadian Institutes of Health Research and was a Career Investigator of the Heart and Stroke Foundation of Canada.


In 1996, Dr. Li was the first to show that stem cells transplanted into scar tissue in the heart survived, differentiated into muscle tissue, and improved heart function. Since this pioneering work, his research has gone on to define the optimal stem cell types for transplantation as well as the ideal conditions under which transplanted cells achieve the most efficient repair of the heart. Most recently, Dr. Li has been uncovering ways to rejuvenate the aged individual using young stem cells to promote tissue repair following injury. Dr. Li’s second research focus involves the development of biomaterials that can easily integrate into damaged heart tissue to facilitate the heart’s conduction to open the door for new treatment options for patients with cardiovascular diseases. Over the past 25 years, Dr. Li’s research has transformed from tissue repair, to regeneration, to rejuvenation.

Dr. Richard D. Weisel, MD, FRCSC

Senior Scientist, Ren-Ke Li Laboratory

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Since 1978, Dr. Weisel’s research efforts have been devoted to the translation of basic science discoveries to new clinical treatments. Dr. Weisel obtained his medical degree from the Marquette Medical School and completed his residency in Cardiothoracic and Vascular Surgery at the University of Toronto. He was the Director of the Toronto General Research Institute from 2005-2011.

As a cardiac surgeon, Dr. Weisel has focused on finding new techniques to improve outcomes. As a surgeon-scientist, he has attempted to apply discoveries from the basic science laboratory to develop new approaches to clinical care. His two areas of interest have been protecting the heart during surgery and regenerating injured hearts with stem cell therapy. Studies on cardioplegic protection led to a series of clinical trials which have established many of the currently employed techniques.

In addition, a number of multi-national clinical trials have evaluated new methods to improve outcomes of cardiac surgery. Together with Dr. Ren-Ke Li and his research time, methods were developed to precondition human cardiomyocytes and it was then discovered that the implantation of these cells prevented heart failure after coronary occlusion. These initial animal studies contributed to the rationale supporting the extensive clinical trials of stem cell therapy in Toronto and worldwide. In addition, he has collaborated with Dr. Tirone David, Dr. Ren-Ke Li, and Dr. Maral Ouzounian to discover the genetic mechanisms responsible for aortic dilatation in patients with biscuspid aortic valve aortopathy. They employed many of the techniques routinely used to evaluate the regenerative potential of stem cell therapy to identify novel targets in the aorta to prevent dilatation.

Dr. Weisel’s major accomplishment has been training two generations of cardiac surgical scientists. He and Dr. Li have a collaborative program which trains both surgeon scientists as well as PhD scientists. They have mentored more than 30 surgeon-scientists and more than 50 PhD scientists who have assumed leadership positions around the world.