This could eliminate one of the biggest risks that comes with an organ transplant.
Organ transplants save thousands of lives each year, but one of the biggest post-procedural hurdles is for a patient’s body to successfully accept the new part. Often, powerful drugs are required to help along the process, but in some cases, organ transplants fail when a patient’s immune system rejects the foreign organ.
Now, scientists from the Massachusetts General Hospital Center for Regenerative Medicine have an innovative solution that brings us one step closer towards creating bioengineered human hearts in a lab.
In this case, the operation still requires using a donated organ, but the organ is fused with cells from the recipient.
Decellularization is a process used in biomedical engineering to isolate a tissue’s extracellular matrix (ECM) — a collection of molecules that provide structural and biochemical support to surrounding cells — from its inhabiting cells.
The process of decellularization was pioneered at the McGowan Institute for Regenerative Medicine, and it creates a natural biomaterial that acts as a frame for cell growth and tissue development.
Basically, by reconstructing an ECM frame with a patient’s own cells, the potential adverse immune response is eliminated.
The technique used by the scientists at the Center for Regenerative Medicine effectively strips the transplantable organ of the original donor’s cells, and the new cardiac tissue is grown from the recipient’s own induced pluripotent stem cells (iPSCs) — effectively eliminating the risk of the patient’s body rejecting the transplant since it would be made from his or her own cardiac muscle cells.
"Regenerating a whole heart is most certainly a long-term goal that is several years away, so we are currently working on engineering a functional myocardial patch that could replace cardiac tissue damaged due [to] a heart attack or heart failure," said researcher Jacques Guyette in a press release.
In the study, 73 human hearts that were authorized for scientific research were used, and the scientists induced the stem cells to differentiate into 500 million cardiac muscle cells. Then, they seeded them into the tissue of the decellularized hearts.
"Generating functional cardiac tissue involves meeting several challenges," said Guyette. "These include providing a structural scaffold that is able to support cardiac function, a supply of specialised cardiac cells, and a supportive environment in which cells can repopulate the scaffold to form mature tissue capable of handling complex cardiac functions."
After several days, the cardiac muscle cells developed into spontaneously contracting tissue. The researchers say this is the first regeneration of human heart muscle from stem cells within a cell-free, human heart matrix — quite the accomplishment.
"Among the next steps that we are pursuing are improving methods to generate even more cardiac cells – recellularising a whole heart would take tens of billions – optimising bioreactor-based culture techniques to improve the maturation and function of engineered cardiac tissue, and electronically integrating regenerated tissue to function within the recipient's heart," said Guyette.
A future with a safer and smoother organ transplantation process is certainly one to look forward to.
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