A new microfluidic concept for successful in vitro culture of mouse embryos

Innovative techniques for gene editing have enabled accurate animal models of human diseases to be established. In order for these methods to be successfully adopted in the scientific community, the optimization of procedures used for breeding genetically altered mice is required. Among these, the in vitro fertilization (IVF) procedure is still suboptimal and the culture methods do not guarantee the development of competent embryos. Critical aspects in traditional in vitro embryo culture protocols include the use of mineral oil and the stress induced by repetitive handling of the embryos. A new microfluidic system was designed to allow for efficient in vitro culture of mouse embryos. Harmful fluidic stress and plastic toxicity were excluded by completing the industry gold standard Mouse Embryo Assay. The potential competence of the embryos developed in the device was quantified in terms of blastocyst rate, outgrowth assay, energy substrate metabolism and expression of genes related to implantation potential. Mass spectrometry analyses identified plastic-related compounds released in medium, and confirmed leaching of low molecular weight species into the culture medium that might be associated to un-crosslinked PDMS. Finally, these data show the potential for the system to study preimplantation embryo development and to improve human IVF techniques.