Regenerative medicine in space

Deep-space missions subject astronauts to chronic microgravity, galactic radiation, disrupted circadian rhythms, and isolation—conditions that trigger oxidative stress, genomic instability, mitochondrial dysfunction, and telomere attrition. Together, these insults sap stem-cell self-renewal and derail the signaling networks required for authentic tissue regeneration. This review condenses the emerging evidence on how spaceflight perturbs the cellular and molecular machinery of repair and surveys practical countermeasures that can be deployed prelaunch, in transit, and during postlanding recovery. In this chapter, we focus on mesenchymal stem/stromal cells, extracellular mitochondria, and other subcellular therapeutics—including engineered extracellular vesicles—that can be expanded or manufactured in microgravity. Multiomics studies revealing shifts in gene regulation, epigenetic state, and bioenergetics underlie our discussion of interventions that range from antioxidant-laden biomaterials and DNA-repair boosters to closed-loop stem-cell bioreactors, 3-D bioprinting, and “living-pharmacy” modules. Because regenerative and tumor-promoting pathways often intersect, we also consider oncogenicity testing and long-term safety monitoring. By integrating current data with forward-looking technologies, the chapter outlines a roadmap for maintaining—and restoring—human tissue integrity throughout the entire arc of interplanetary travel, while offering insights that can equally advance regenerative medicine on Earth.