After decades of searching for a replacement heart that would save heart patients from long waiting lists to obtain a suitable donor, the Japanese University of Osaka came out with the result of years-long research, in which scientists used stem cells taken from the patient’s own tissues to grow a replacement heart the size of a ping-pong ball.
The origin of this achievement dates back to 2012, when doctor Shinya Yamanaka won the Nobel Prize after discovering the technique of converting normal cells into induced pluripotent stem cells, which opened the door to this project, which was later led by Japanese heart professor Sawa Yoshiki from Osaka University, investing years of his research to achieve the dream of an autologous transplanted heart.
The heart transplant process begins with taking a small sample of the patient’s heart cells, which are reprogrammed to become induced pluripotent stem cells, and then guided by precise biological signals to transform into cardiac muscle cells.
These cells are assembled into a three-dimensional structure to form miniature cardiac tissue, which is placed in a warm, nutrient-rich solution and begins beating on its own, as if it were a living heart in the making.
This discovery gives hope to thousands of patients who die while waiting for a suitable donor, or suffer from rejection of the transplanted heart and are forced to use immunosuppressive medications for life.
A heart transplanted from the patient’s own cells avoids these risks, as it is made from his own tissue, and the body accepts it without rejection.
The CurePass company, run by Sawa Yoshiki, is currently conducting clinical trials to implant patches of this cardiac tissue in the chests of patients. Preliminary results have shown that these patches act as living bandages that reactivate the weakened heart muscle and help it regain some of its functions.
Side risks
But there is still a long way to go from a ping-pong ball-sized heart to a fully transplantable human heart.
The greatest danger lies in the possibility that these cultured cells may turn into cancerous tumors if they are not carefully monitored, in addition to challenges related to the harmony of the electrical rhythm of the transplanted tissue with the natural heartbeat, and this may cause serious disturbances in the work of the cardiovascular nervous system.
Despite the amazing progress, the natural heart still excels in its superior ability to pump and regulate, as it pumps 5 liters of blood every minute with amazing precision through valves and chambers that work in perfect harmony, which laboratory experiments have not yet been able to fully replicate.
Therefore, scientists are working to develop fine blood vessel networks within implanted tissues using 3D printing techniques to form the heart with anatomical accuracy. They are also developing biostimulators that mimic the natural environment inside the human body.
Mechanical hearts and ventricular assist devices, which have saved thousands of lives, still face challenges such as infections, clots, and the need for periodic replacement.
But a heart cultured from the patient’s own cells represents a qualitative leap, as it is a living organ that grows with the body and interacts with its needs, not just a machine that pumps blood, but a new heart born from the body itself.