"Studying stem cells in space has uncovered cell mechanisms that would otherwise be undetected or unknown within the presence of normal gravity," explained Dr. Zubair. "That discovery indicates a broader scientific value to this research, including potential clinical applications."

Dr. Zubair has launched multiple stem cell experiments to the ISS, with each mission examining whether space conditions are ideal for cultivating a large quantity of potent stem cells. His research investigates whether space-grown cells retain their efficacy upon returning to Earth.

"The goal of almost all space flight in which stem cells are studied is to enhance growth of large amounts of safe and high-quality clinical-grade stem cells with minimal cell differentiation," said Dr. Zubair. He hopes that studying these space-cultured cells could pave the way for treatments targeting age-related diseases, including stroke, dementia, neurodegenerative disorders, and cancer.

Challenges in Growing Stem Cells on Earth
Adult stem cells sourced from bone marrow and fat tissue naturally resist division and specialization, meaning the number of these cells in any patient remains limited. To meet the demand for clinical and research applications, scientists must multiply these cells, a process that is costly, time-consuming, and often yields inconsistent outcomes.

Experiments conducted on the ISS have shed light on the behavior of stem cells, showing how microgravity supports enhanced cell growth and function. In space, cells can grow in a more realistic three-dimensional structure, which mimics conditions in human tissue far better than the two-dimensional culture methods available on Earth.

"The space environment offers an advantage to the growth of stem cells by providing a more natural three-dimensional state for their expansion, which closely resembles growth of cells in the human body," Dr. Zubair noted.

Insights from Space-Grown Stem Cells
Research into space-expanded stem cells suggests potential applications in disease modeling. These cells could be grown to simulate realistic models of conditions like cancer, enabling scientists to observe disease progression and test innovative treatments in vitro.

Several cell types studied in space have demonstrated promising clinical implications:

- Mesenchymal stem cells, adult stem cells known for their healing properties, showed enhanced immunosuppressive abilities when expanded in microgravity.

- Hematopoietic stem cells, which are critical for blood regeneration, displayed potential to differentiate into red and white blood cells, offering a possible future therapy for blood cancers.

- Cardiovascular progenitor cells could support heart tissue repair by promoting growth in the blood vessels and muscles essential for recovery after a heart attack.

- Neural stem cells maintained regenerative abilities after returning from space, sparking interest in their potential for treating central nervous system diseases.

Addressing Obstacles in Space-Based Research
Despite the exciting possibilities, space stem cell research poses notable challenges. Prolonged exposure to microgravity might weaken cells, impacting their performance once back on Earth. Additionally, cosmic radiation may damage cellular DNA, though Dr. Zubair's team found no evidence of chromosomal damage leading to cancer in mesenchymal stem cells grown in space.

"Stem cell research in the cosmos is in its early stages, and the full effects of multiplying cells in weightlessness are not fully understood," Dr. Zubair wrote. He emphasized the need for continued research, funding, and a deeper exploration of space's potential for advancing regenerative medicine.

The research received funding from NASA and the Mayo Clinic's Center for Regenerative Biotherapeutics.

Research Report:Discoveries from human stem cell research in space that are relevant to advancing cellular therapies on Earth

Related Links
Center for Regenerative Biotherapeutics at Mayo Clinic
Space Medicine Technology and Systems