Growing a new heart from stem cells

Researchers at Massachusetts General Hospital (MGH) have successfully developed bioengineered human heart tissue, opening up possibilities for future advancements in the stem cell research field.

Stem cells are specialized cells that can self-renew and produce two identical cells from a parent cell. Embryonic stem (ES) cells are easily manipulated and can give rise to various specialized cell types, which is very promising in the biomedical research field. Derived from embryos that have been fertilized in clinics with the consent of donors, rather than eggs that have been fertilized in a human body, ES cells can be used for growth, renewal and repair. Because many serious medical conditions are due to abnormal cell division or differentiation, stem cells provide the opportunity to understand how many diseases arise and allow doctors to test new therapeutic strategies.

Led by Harald Ott, known for his work in whole organ regeneration, a team of researchers at MGH performed a study of 73 human hearts deemed unsuitable for transplantation. The team stripped cells from hearts from people who had undergone cardiac death and reprogrammed them with stem cells from donor hearts. The regenerated tissue had the appearance of undeveloped cardiac tissue and demonstrated functional contractions in response to stimulation.

“This regeneration of working cardiac tissue developed from stem cells is thrilling because it paves the way for future advancements in the cardiothoracic field that could replace damaged tissue due to heart attacks or heart failures. It shows that the regeneration of a whole heart and is a possibility and that bioengineered organs could possibly alleviate the extreme demand for transplantable organs,” Sophomore Timothy Yuan said.

However, many technical barriers still stand in the way of immediate use of stem cell therapies. Scientists need to research strategies to generate tissues that are not only available in sufficient quantities, but can also differentiate successfully and survive and function in the recipient. In addition, many still have qualms about stem cell research due to the creation, use and destruction of human embryos.  

“Although stem cell research does hold great potential for new treatments for diseases and much more, it is not worth it if ethical lines are crossed and human embryos, potential lives, are being manipulated and destroyed,” Junior Meghan Connolly said.

With scientists discovering how to stimulate patients’ own cells to behave like ES cells and other alternatives, such as in the MGH project, the moral issues surrounding stem cells are becoming increasingly inapplicable. However, until researchers find a way to completely eliminate the use of human embryos in stem cell research, the possibilities of stem cells cannot be fully explored.

Although stem cell research is still in early stages regarding the regeneration of organs, scientists have opened up possibilities for future projects.