Aging Mammalian Tissues In Vitro (R21 Clinical Trial Not Allowed)

The Department of Health and Human Services, through the National Institutes of Health, and specifically the National Institute on Aging, has released a Notice of Funding Opportunity inviting applications under the title Aging Mammalian Tissues In Vitro (R21 Clinical Trial Not Allowed). This program is announced under the activity code R21, which is designed for exploratory and developmental research grants at the early and conceptual stages of project development. The primary objective of this program is to support interdisciplinary research to develop advanced three-dimensional mammalian in vitro microphysiological systems to model and recapitulate aging processes observed in vivo. While the primary emphasis is on human cell-derived systems, models based on nonhuman mammalian sources may be considered for benchmarking or validation purposes if relevant to understanding human aging biology. The purpose of this program is to advance the scientific tools available for aging research and drug discovery by building systems that can faithfully replicate aging processes in tissues and organs. Current animal models provide significant insights but often fail to capture human-specific mechanisms of aging, limiting their translational relevance. By leveraging microphysiological systems such as tissue chips, organ-on-chip models, and organoids, researchers can create in vitro environments that mimic the complexity of human tissue and organ aging. Supported projects are expected to incorporate multidisciplinary expertise spanning aging biology, stem cell biology, tissue physiology, bioengineering, computational biology, pharmacology, and related fields. The funding available through this opportunity is approximately $2.4 million in fiscal year 2026 to support an estimated ten awards. Individual application budgets are capped at $275,000 in direct costs across the two-year period, with a maximum of $200,000 in any one year. Projects may not exceed a duration of two years. Applications that focus on developing systems that do not inform aging, that lack multiple cell types, or that primarily aim at scaling assays for compound screening or regenerative medicine will not be considered responsive. Instead, the emphasis is placed on systems that can recapitulate aging phenotypes, benchmark against clinical or organismal data, and demonstrate feasibility for broad adoption in aging research. Eligible applicants include higher education institutions, nonprofit organizations, for-profit entities including small businesses, state and local governments, tribal governments, independent school districts, housing authorities, and other regional and community-based organizations. Foreign organizations are not eligible to apply, though foreign components within U.S. organizations may participate. Applicants must complete required registrations through SAM.gov, Grants.gov, and eRA Commons before submission. Each application must designate at least one Program Director/Principal Investigator with an active eRA Commons account. Applications will be accepted beginning September 20, 2025, and the final submission deadline is October 20, 2025, by 5:00 p.m. local time of the applicant organization. Applications will undergo peer review by the NIH Center for Scientific Review, with scientific merit review expected in March 2026, advisory council review in May 2026, and earliest possible award start dates in July 2026. The funding opportunity will expire on October 21, 2025. Applications must comply with the NIH Data Management and Sharing Policy and include plans for data sharing, validation metrics, and milestones to measure success. Evaluation of applications will focus on three main factors: the importance of the research and its potential impact on aging science, the rigor and feasibility of the proposed approach, and the expertise and resources available to the investigative team. Reviewers will consider the degree of innovation, the capacity to faithfully reproduce aging phenotypes, and the potential for reproducible results. While preliminary data are not required, applicants must provide a clear rationale, describe aging phenotypes of interest, and benchmark against human or clinically relevant data. High-risk, high-reward projects are encouraged, as are collaborations that support consortium participation and sharing of resources. For further information, applicants may contact the Scientific/Research lead, Dr. Tiziana Cogliati at the National Institute on Aging, reachable at 240-397-4596 or tiziana.cogliati@mail.nih.gov. Financial and grants management questions may be directed to Mitchell Whitfield at 301-827-6373 or mitchell.whitfield@nih.gov. Questions regarding peer review should be sent to NOFOReviewContact@csr.nih.gov. General questions regarding applications may be addressed to GrantsInfo@nih.gov or the Grants.gov help desk at 800-518-4726. All applications must be submitted electronically through NIH ASSIST, institutional system-to-system portals, or Grants.gov Workspace.

Apply early to correct errors. Ensure NIH application instructions are followed. Consortium participation and resource sharing expected.