Microfluidic Fibroblast Cell Culture Chip for Embryo Co-Culture: Analysis of Preimplantation Embryo Viability and Development Potential.

Preimplantation embryo development requires a tightly regulated microenvironment that is not fully reproduced by conventional static culture. We developed a polydimethylsiloxane-based microfluidic embryo co-culture platform integrating compartmentalized architecture with dynamic perfusion to simulate physiological conditions. The study included two stages. First, NIH/3T3 mouse fibroblasts were evaluated as helper cells under three culture conditions after transition to embryo culture medium. Helper-cell viability in the dynamic chip was 84.72%, compared with 71.91% after manual medium replacement in 24-well plates and 94.27% in the 24-well control group. Second, mouse embryos were cultured under four conditions: conventional 24-well plates, static microfluidic chip culture with co-culture, dynamic microfluidic chips without co-culture, and dynamic microfluidic chip co-culture. Blastocyst formation rates were 100.0% (9/9), 0.0% (0/6), 33.3% (3/9), and 55.5% (5/9), respectively. Because no inferential statistical analysis was performed, these proportions are interpreted descriptively. Nevertheless, the blastocyst formation in the microfluidic co-culture group supports the technical feasibility of integrating dynamic perfusion and helper-cell co-culture within a single platform. Further optimization and validation are required. This platform provides a foundation for future development of advanced embryo culture technologies including patient-specific endometrial co-culture systems in assisted reproduction, disease modeling, or drug development.