“Fight for Every Heartbeat”.
This slogan from the British Heart Foundation appropriately illustrates the constant battle between Man and his arduous search to sustain life through natural and artificial means, by relying on heart transplants, or oddly-shaped gadgets (like pacemakers) that are sewn permanently onto his fragile body. The need for heart transplants is constant.
According to the British Heart Foundation, on average, three people die daily in the United Kingdom while waiting for an organ transplant. Nine out of 10 people advocate organ donation. However, did you know that only a mere three out of 10 people act on their pledge by signing the Organ Donation Register?
Unfortunately, adults are not the only ones that are affected by this problem. According to the Registry of the International Society for Heart and Lung Transplantation, approximately 350 to 400 paediatric heart transplantation procedures are performed worldwide each year, representing about 10% of the total number of heart transplants.
Therefore, it is crucial that there is a constant supply of hearts so that millions can be saved. “How do we then maximise the use of suitable donor hearts to suit the needs of patients?” you may wonder. Behold, the latest medical breakthrough – using stem cells to grow a live, personalised human heart!
Research scientists are currently growing live human hearts in laboratories, and offering hope for millions of cardiac patients. It is believed that the artificial hearts could start beating in weeks and that this technological marvel could pave the way for livers, lungs or even kidneys to be made to order.
The process of ’breeding’ a new heart is a simple, yet a tedious one. Once the donor heart is removed from the body, enzymes and detergents are used to get rid of cells from the heart, leaving behind a protein ‘carcass’, or a ‘skeleton’ of the heart. Stem cells taken from the patient are then added to the heart ‘skeleton’ and as these stem cells multiply and produce new heart cells, it is predicted that the heart will start beating soon enough.
Patients who receive normal heart transplants are given immunosuppressants to ensure that their body does not reject the newly transplanted heart. However, these drugs may increase the risk of high blood pressure, kidney failure and diabetes.
The latest technology, however, involves the transplantation of a heart that is made up of the patient’s own stem cells. Therefore, there is little chance that the body will reject the heart. Sounds like a win-win situation? Well, not exactly. This is where the REAL problem begins.
Stem cell research. Sounds familiar?
Stem cells are like building blocks of the body and there are different types of them: embryonic stem cells; adult stem cells; and induced pluripotent stem cells. Embryonic stem cells probably have the greatest potential to become any one of the 220 different cells in the body.
Scientists can use them to treat failing hearts or even grow hearts if the embryonic cells successfully became heart cells. However, their use is a contentious issue and raises ethical dilemmas (weighing the duty to prevent or alleviate suffering against the duty to respect the value of human life). This is because an early-stage embryo has to be destroyed in order to obtain embryonic stem cells. This may lead to a potential human life being killed.
This ethical issue does not apply to the technology mentioned above, which uses adult stem cells taken from the patient. But embryonic stem cells could be the key to the discovery of other new medical treatments that could potentially alleviate the suffering of many people.
It is a daunting task to please all parties concerned in the ethical debate. However, a study made in 2013, found that a different type of cell could be made to behave as a stem cell and could possibly be used to artificially engineer new tissue.
This discovery involves a biological process called parthenogenesis. It is a form of asexual reproduction that occurs naturally in plants, insects and fish, but not in mammals. In this process, unfertilized eggs start to develop as if they had been fertilized.
Researchers induced human egg cells with chemicals replicating fertilization, so they would undergo a similar process. The resulting cells were almost the same as embryonic stem cells and could possibly specialize into different cells, even into heart cells.
Interestingly, the discovery of parthenogenesis and the successful execution of it in mammals were made much earlier, in 2007, by a Korean Scientist and his team. That paved the way to producing a human parthenogenetic stem cell line now. Scientists are still testing this method but it is possible that this discovery could resolve the ethical issues about stem cell research and save lives.
For now, we will just have to wait and see what will arise from all this …
Mohamed Shafie Bin Allameen is a Junior College student who had undergone internship at Science Centre Singapore (SCS) in Nov/ Dec 2013. He has written this blog post during his internship at SCS before the recent research development in the creation of embryonic stem cells in Japan.