ABSTRACT Embryos cultured external to the body are exposed to non-physiologic conditions that can impair the health of the future adult. Moreover, culture stress reduces immediate embryo viability and implantation success, motivating multiple embryo transfers and leading to high rates of multiple pregnancies. These pregnancies are risky for fetus and mother and exhibit a high healthcare cost burden. To address this, embryos are screened based on early-stage morphology to identify the healthiest for transfer, but this approach achieves limited success and is highly dependent on the individual conducting the test. An accurate and objective screening method would increase implantation rates and reduce the need for multiple transfers, in addition to yielding healthier offspring. The objective of this project is to develop a new technology for noninvasive IVF embryo selection. Dr. Paolo Rinaudo, Co-I on this grant, is a Reproductive Endocrinologist working at the UCSF Center for Reproductive Health which performs >2000 IVF procedures per year and has commitment to research. Through experience derived from two decades of work in IVF, he identified that current methods for screening embryos are inadequate, with the gold standard, morphological selection, achieving a positive predictive value of just 30%. While an embryo may appear morphologically healthy, it may not be molecularly healthy, which may affect the long-term development of the fetus. Among his two decades of research on cultured embryos and IVF is the finding that ex vivo culture can stress embryos and drive Warburg-like metabolism. In addition, culture stress has now been correlated to long-term negative health outcomes, including abnormal placental development, metabolic dysfunction, hypertension, and diabetes. Dr. Rinaudo hypothesized that metabolically active embryos lower their culture droplet pH, similar to how Warburg metabolism acidifies the environment around cancer cells, thereby affording a simple way to select the best embryos for transfer. His research has confirmed this, but the technique cannot be translated to practice because there is no effective and reliable pH measuring method for the culture droplet due to its tiny volume. Armed with this concept, he reached out to Dr. Adam Abate, a physicist and engineer at UCSF. Dr. Abate is a leader in microfluidics and nanotechnology with a record of developing and translating health care technologies to practice, having founded multiple companies commercializing his inventions, including Fluent Biosciences (genomics), Mission Bio (oncology diagnostics) and Scribe (cell & gene therapy). Together, Drs. Rinaudo and Abate have designed a novel hydrogel biosensor that non-invasively measures culture droplet pH. Being an IVF clinician, Dr. Rinaudo is aware of the regulatory and practical constraints of IVF operations and thus ensured the design is feasible for this setting by making it simple, non-invasive, and cost-effective. This grant will develop the technology and validate its efficacy in a mouse model of IVF, providing critical data for a follow-on R01. The project is thus based on a rigorous scientific foundation, decades of clinical experience, and comprises a team capable of translating science discoveries to the clinic.

NARRATIVE The objective of this project is to develop a new technology with which to identify the healthiest embryos for IVF implantation. This will increase success rates, reduce multiple pregnancies and abortions, and yield healthier offspring generated by IVF procedures.