As of now, there’s a total of over 4,000 persons waiting for a heart transplant in the United States only. However, there’s a huge donor shortage and not all of these patients will make it. This fact basically highlights why the dream of being able to grow a transplantable heart in laboratory is so important to the medical community. A recent study published in the Circulation Research journal has brought this dream one step closer to becoming a reality. The study is conducted by a team of researchers that has grown a beating a human heart in a lab using stem cells.
It has been shown previously that 3D printers can be used for the manufacturing of 3D heart segments by utilizing biological material and although these structures do not contain actual heart cells, they do provide the ‘scaffold’ upon which heart tissue can be grown. The team that we talked about earlier is composed of members from Massachusetts General Hospital (MGH) and Harvard Medical School and made use of this scaffolding concept in collaboration with stem cells for achieving some really amazing results.
Moving back to heart transplants, it sure is quite a hassle to arrange for a donor but that’s not the only problem here. The more risk-associated problem is receiver’s body rejecting the new organ because of the immune system identifying it as a foreign object and treating it as a threat by attacking and destroying it. How do you stop that from happening? The usual practice is to make use of drugs that would suppress the immune system – successful only in some cases.
A total of 73 human hearts that had been classified as unsuitable for transplantation were used for the study. These hearts were submerged into solutions of detergents, thus stripping away any cells that could trigger the self-destructive response we just talked about. The end result was a matrix of the heart featuring the complete intricate structure and vessels, providing a foundation for new heart cells to be grown onto.
The next step incorporated stem cells into the mix. These cells have the peculiar ability to become any sort of cell in the body. For this particular research, human skin cells were reprogrammed into stem cells and subsequently, made to transform into two kinds of heart cells. Within 2 weeks, the networks of lab-grown heart cells resembled immature but detailed structured hearts. The team then provided them with a burst of electricity and the hearts started to beat.
Jacques Guyette, a biomedical researcher at the MGH Center for Regenerative Medicine and lead author of the study said, “Among the next steps that we are pursuing are improving methods to generate even more cardiac cells. Although this study manufactured a whopping 500 million stem cell-derived heart cells for the procedure, re-growing a whole heart would actually take ‘tens of billions’.”