Much has happened since, in 1967, Christiaan Barnard’s team carried out the first heart transplant in history in a South African hospital. Since that milestone in the history of medicine, organ transplantation techniques have evolved tremendously, but major pitfalls remain: the availability of donors and the rejection of transplanted organs.
Current research goes one step further, and experts already predict that in the not too distant future, transplanted organs will not come from compatible donors but from the individual’s own body. They will be organs created from their tissue and printed with 3D technology, as is already done in many prostheses. But, for this idea to stop being science fiction, many obstacles still have to be overcome: an organ is not a mere mass of cells, but rather has a very complex structure and function, something that is not so easy to imitate in the human body. laboratory. Until now, ‘only’ simple tissues have been printed without blood vessels.
A team of scientists from Tel Aviv University has gone one step further and has just announced the creation, from human tissues, of a 3D printed heart that is capable of beating on its own. “This is the first printed heart that is filled with cells, blood vessels, ventricles and chambers, ” explained Tal Dvir, director of the research. “This heart is made of human cells and biological materials from the patient.”
To achieve this, a fatty tissue biopsy was taken from the chosen patients and the cellular materials were separated from the extracellular matrix, which contains elements such as collagen and glycoproteins. These compounds were used to make a custom hydrogel that served as a printing ‘ink’. And it is that one of the problems that 3D printing of organs presents is that they are composed of soft tissue, and the materials collapse under their own weight, so it is necessary to manufacture a hydrogel that provides adequate structural support.
On the other hand, the cells taken from the patients were reprogrammed to become pluripotent stem cells. After mixing with the hydrogel, they differentiated into cardiac and endothelial cells, compatible with the immune system of each patient and with blood vessels. The use of ‘raw material’ specific to each individual is, according to the authors of the work, essential to complete the process successfully. ” The biocompatibility of the designed materials is crucial to eliminate the risk of implant rejection, something that jeopardizes the success of the treatments “, explains Dvir. “Ideally, the biomaterial should have the same biochemical, mechanical and topographic properties of the tissues of the patient himself ”.
A long way to go
Although the advances in regenerative medicine are promising, it is not yet time to raise the bells. In this case, it is still pending to ‘teach’ the heart to function as an organ, since its cells beat, but do not beat. ” They can contract, but they don’t have the ability to pump, we need them to work together .” Another challenge is to get a heart similar in size to a human (the one made by Israeli scientists is the size of a rabbit) and start testing the organs in animal models.
Still, there are reasons for hope. “Perhaps, in ten years, there will be organ printers in the best hospitals in the world, and these procedures will be performed routinely,” concludes the researcher.
Referencia: Noor et al. 2019. 3D Printing of Personalized Thick and Perfusable Cardiac Patches and Hearts. Advanced Science DOI: 10.1002/advs.201900344
Foto: Advanced Science. © 2019 The Authors.