Heart disease is the number one cause of death in the Western world. The number of available donor hearts is frighteningly low. After a 3-year stint at MIT, Dr. Tal Dvir and his team have constructed biocompatible, bio-inspired materials that re-create the humans’ stem cells into functioning 3-dimension cardiac tissue. Gold nanowires are interspersed within these biomaterials both to enhance cell performance and trigger necessary electrical conduction. Dvir’s team has already demonstrated that engineered heart tissues can be incredibly effective following heart attack. In a new project, Tal will be integrating nanoelectronics with engineered tissue called cyborg tissue to act as a kind of pacemaker that will monitor heart performance online. His team is now looking to bring such devices into the clinical world.
A heart attack is the death of or damage to part of the heart muscle when its blood supply has been severely reduced or stopped. It is an irreversible process. Heart disease is the leading cause of death in the Western World. Approximately 50% of patients who have a first heart attack die within five years.
Right now, the only cure is a heart transplant. In the US, about 3,100 people are on the waiting list for a heart transplant on any given day. Only 2,200 donor hearts are available each year. Less than 600 donor hearts become available each year in Europe and only about 3,500 worldwide. 48% of people listed for a donor heart have been waiting for more than a year.
There is an urgent need to develop new strategies that will promote heart regeneration.
DR. TAL DVIR SEEKS PERFECTION. His TAU Laboratory for Tissue Engineering and Regenerative Medicine is on the way to growing cardiac tissue to repair broken hearts, brains, spinal cords, and more.
Tissue Engineering is an interdisciplinary technology using principles from the life, material, and engineering sciences to develop functional substitutes for damaged tissues and organs, where the cells are seeded in or onto biomaterials that serve as temporary scaffolds, supporting the cells and promoting their reorganization into functional tissue. The engineered tissue then heals the defected organ and the biomaterial degrades.
APPROACH #1: THE HEART
The design and engineering of cardiac muscle tissue requires biomaterials that can supply a wide assortment of biological, mechanical, and chemical cues, compared to that of, for instance, skin tissue used in grafting. The heart has to pump, contract, speed up, and slow down; skin has to cover. A heart needs an elastic environment; a bone needs a stiff environment. So-called universal biomaterials do exist; they just aren't ideal for the heart.
The Dvir Group has already engineered a contracting cardiac patch with "beautiful results" in the lab. However, until this point, they have been using universal biomaterials to engineer functioning tissue in the lab.
The team is now ready to launch an in-depth study of heart tissue and on the way to:
- Engineering thick, viable synthetic tissue more suitable for transplantation than the tissues grown in the universal biomaterials;
- Creating blood vessel networks within the cardiac patch to allow perfect integration after transplantation;
- Creating patient-specific cardiac patches using the patient's own stem cells; and
- Following tissue function after it's transplanted.
The Laboratory for Tissue Engineering is developing smart micro and nanotechnological tools — ranging in size from one millionth to one billionth of a meter. Group-developed micro-channeled biomaterials can easily accommodate blood vessel networks to support the heart; and a nanoelectronic device has had success reporting and controlling tissue function.
Dr. Dvir and his team are also now investigating the ability of this cyborg tissue to report on or monitor the function of the engineered tissue after it is transplanted into animals that have suffered a heart attack.
During his post-doc research at the MIT Langer Lab, Dr. Dvir and his colleagues developed a smart nanoparticulate system — using particles one billionth of a meter in size that, after a heart attack, could be injected intravenously into in the blood stream, find their way and attach themselves to the heart and then recruit stem cells to repair the heart. The TAU Lab is now investigating this treatment in animals.
APPROACH #2: THE BRAIN AND SPINAL CORD
The death of neuronal networks resulting from physical injuries to the brain and spinal cord are among the leading causes of death and chronic disability. The human body can't regenerate nerve tissues because these cells simply don't divide. So, there is a strong interest in cell replacement therapies.
The Dvir Group is developing new biomaterials that can support the assembly of a functional three-dimensional neuronal network. An engineered nano-wired tissue composed of nerve cells could assist paralyzed patients by rerouting movement-related signals around injured parts of the nervous system. They can also serve as vehicles for efficient transplantation and viability maintenance of neuronal stem cells.
Example: These new biomaterials could support the transplantation of dopaminergic stem cells in Parkinson's Disease models, ensure precise delivery and a long cell life.
Both approaches are critical steps in basic science that will lead to the creation and transplantation of human organs. The possibilities are endless.
DR. TAL DVIR was born and raised in Israel; was a paratrooper in the IDF; was recruited and worked as a highly classified government operative for eight years; and finally went off to college in 2003, earning his BSc and PhD in Biotechnology Engineering from Ben-Gurion University of the Negev.
Dr. Dvir joined the MIT Laboratory of David H. Koch Institute Prof. Robert Langer in 2008 as a Postdoctoral Fellow. Dr. Langer is the most cited engineer in history and one of only 14 Institute Professors, MIT's highest faculty honor. Prof. Dvir worked in the lab for three years, researching micro and nanoscale technologies for tissue regeneration, until he was invited by Technion, Bar Ilan, and Tel Aviv Universities to join as a faculty member. "Tel Aviv University is the biggest University in Israel, with a truly interdisciplinary campus. This is the only Israeli institution where I can easily collaborate with people from the schools of medicine, chemistry and engineering."
He opened the Laboratory for Tissue Engineering and Regenerative Medicine in 2011. In his short career, Dr. Dvir has already received a fellowship from the American Heart Association and the Marie Curie Award for Young Investigators and the Elizabeth and Nicholas Slezak Super Center Award for Cardiac Research, among other prestigious awards.