This proposal is a design-directed project to develop a novel microfluidic bioreactor that will culture multiple single embryos under simulated physiological conditions while simultaneously performing real-time monitoring of biochemical markers of embryo quality. Reducing the incidence of high-order multiple pregnancies while maintaining the overall IVF success Irate is a holy grail of human IVF and would be greatly assisted by the ability to produce and identify the highest quality embryos. This goal has been elusive to date due, at least in part, to the lack of instrumentation to perform convenient and reliable single embryo manipulation and analysis. Because of the small quantities of biomarkers produced by single embryos, reliable quantification hinges on the ability to culture the embryos in very small volumes of fluid and to directly analyze the culture media for soluble biomarkers secreted by embryos with minimal dilution. The proposed microbioreactor with microfluidic pumps, valves, and sensors will provide an inherently biomimetic milieu for embryo culture as well as enable direct biomarker analysis on chip. The microbioreactor will utilize a computer-controlled integrated microfluidics platform that controls fluid flow inside elastomeric capillaries by deformation of the microchannels with mechanical microactuators. The biomarkers of mouse embryo health that will be monitored in this exploratory grant are embryo metabolites, autocrine factors, and embryo surface biomarker of embryo health. The embryo microbioreactor will be used to specifically test the hypothesis that analysis of select biochemical markers will enable prediction of which 8 cell embryo will proceed to produce healthy blastocysts. This test will mainly serve the purpose of device validation and concept feasibility but it also has clinical relevance. A current trend is to grow embryos to the blastocyst stage and transfer the two morphologically """"""""best"""""""" blastocyst. Recently, however, two reports using mouse embryos have independently demonstrated that extended culture to the blastocyst stage causes aberrant genetic imprinting and altered postnatal development, growth, physiology and behavior. Case reports and studies also suggest a general association between in vitro culture to the blastocyst stage and MZ twinning. This proposal will address these issues by developing novel non-invasive means of selecting embryos with the greatest implantation potential, with the least amount of manipulation and culture.
