Aging is increasingly understood as a gradual loss of biological stability. DNA accumulates damage, protein homeostasis collapses, and cells drift away from youthful identities as regulatory networks lose their balance over time. These changes ripple across tissues and organs, driving many of the diseases associated with aging. Today, new tools in synthetic biology, artificial intelligence, and gene editing are revealing how these systems might be stabilized, repaired, or even reset. Researchers are engineering enhanced DNA repair mechanisms inspired by long-lived species, using AI to map the trajectories of cellular aging and uncover rejuvenating interventions, and developing therapies that restore protein metabolism to protect vulnerable tissues such as the brain. This session explores how scientists are moving beyond simply slowing aging to engineering the biological systems that maintain cellular integrity. By targeting the underlying mechanisms that govern genome stability, proteostasis, and cellular identity, researchers are laying the groundwork for a new generation of longevity therapeutics designed to restore function and resilience across the lifespan.

Despite major advances in the biology of aging, there are still no interventions that clearly slow or reverse aging in humans. In contrast, modern medicine already depends on replacement to restore lost function, from artificial joints and cardiac devices to organ transplants and stem cell therapies. This session examines how a similar framework could be applied to aging: rather than repairing deteriorated cells and tissues, scientists and companies are exploring ways to replace them with newly generated, biologically young equivalents. The discussion will highlight emerging capabilities in engineered cell sources, scalable tissue fabrication, and programmable biology (instead of "integration") strategies that are redefining what can be rebuilt and replaced. New approaches are beginning to address long-standing challenges such as age-related signaling environments, vascularization, and even circuit compatibility in parts of the brain. Together, these advances point toward a future where rejuvenation is achieved through deliberate biological reconstruction. The session asks: How far can replacement take us, and could rebuilding youthful parts become a central path to extending healthy lifespan?