By studying and engineering heart tissue in the unique low-gravity environment of space, the laboratory of Arun Sharma, PhD, is uncovering new ways to protect and repair the failing heart. He addressed the 46th Annual Meeting and Scientific Sessions of the International Society for Heart and Lung Transplantation (ISHLT) today in Toronto.
Dr. Sharma described space as a yin-yang environment that both accelerates tissue aging and degradation and provides an ideal setting for growing more complex, three‑dimensional heart tissues and patches from patient‑specific stem cells.
Heart disease experiments conducted in space produce fast results
"In microgravity, cardiovascular deconditioning is accelerated; the heart and muscles weaken much faster than on Earth," said Dr. Sharma, PhD, Director of the Center for Space Medicine Research at Cedars-Sinai in LA. "It allows us to study disease-like changes such as weakening contractility and metabolic shifts over weeks instead of years."
Among Dr. Sharma's projects are experiments on the International Space Station on the cellular mechanisms underlying heart failure, as well as harnessing stem cells to produce mini heart organs.
"Gaining a better understanding of how heart muscle fails and recovers can also improve pre‑transplant optimization, keeping patient hearts and other organs in better shape while they wait for a donor organ," he said.
Low gravity can also be harnessed to manufacture heart organoids or miniature 3D organs that simulate normal heart function. Heart organoids are used to identify new drug targets designed to slow the progression of heart failure and improve post-transplant care by producing insights into how cardiac tissue adapts, remodels, or deconditions under stress.
Microrgravity environment helps produce robust therapies
"Microgravity also improves the 3D structure and blood vessel networks in engineered tissue," he said. "Space‑enhanced manufacturing could facilitate the bioprinting of stronger, more physiologic cardiac patches."
Induced pluripotent stem cell (iPSC)–derived heart muscle patches are designed to stabilize or partially repair failing hearts, buying time for and reducing the number of patients who need full organ replacement.
"iPSC patches are being produced here on Earth as bridge therapies for patients with severe heart failure waiting for a complete heart transplant," Dr. Sharma said. "A microgravity environment offers the potential to produce thicker, more robust patches less prone to collapse under gravity when brought back to Earth," he said.
Long-term, Dr. Sharma said space research could also enable a more precise 3D organization of cells and the extracellular matrix, potentially yielding more durable or more physiologic valves, conduits, and support structures.
"For transplant programs, that would mean longer‑lasting valve replacements and structural repairs, fewer re‑operations, and possibly delayed need for full transplant in some patients," he said. "If microgravity lets us produce larger, well‑vascularized 3D heart tissues, we may be able to eventually engineer substantial portions of myocardium suitable for patching large infarcts or even replacing sections of a failing transplanted heart."
The work of Dr. Sharma's lab is part of the vision for on‑demand organ or tissue fabrication, such as iPSC‑derived heart cells from specific genetic backgrounds or disease phenotypes.
The annual meeting and scientific sessions of ISHLT are being held from 22–25 April at the Metro Toronto Convention Centre in Toronto, ON, Canada.
Losing weight improves heart muscle contraction in people with obesity and heart failure