Microfluidic Intracytoplasmic Sperm Injection (MICSI): A Novel Platform for Sperm Isolation, Selection, and Injection Into Oocytes

BACKGROUND: Infertility is a pressing global health concern, affecting one in six couples worldwide. The failure rate for assisted reproductive technologies (ART) cycles remains at approximately 78%, with limited improvements often attributed to a lack of technological innovation. Sperm processing, a crucial component of ART success and offspring health, has seen minimal technical advancement, and current "gold-standard" methods such as density gradient centrifugation (DGC) carry risks of iatrogenic injury and DNA damage. OBJECTIVES: Microfluidic sperm selection technologies have shown promise in leveraging sperm's unique motility behaviors by mimicking the female reproductive tract's microarchitecture. METHODS: In this study, we introduce a microfluidic ICSI (MICSI) platform by integrating microfluidic technology into the form factor of commercially available ICSI dishes, to integrate semen processing, motility and hyaluronic acid (HA) binding-based sperm selection, and oocyte insemination capacity on one single-use consumable. Sperm DNA fragmentation index (DFI), motility, binding score, and sperm morphology were measured to evaluate the performance of the MICSI device compared to DGC and DGC plus HA binding. RESULTS: Practically, the MICSI device was able to select a population of spermatozoa from raw semen with higher progressive motility (p < 0.0001), better morphology (p < 0.0001), and lower DFI (p < 0.0001). When compared to the conventional DGC, the MICSI device produced spermatozoa with significantly higher progressive motility (p < 0.0001) and lower DFI (p < 0.0001). DISCUSSION AND CONCLUSION: This data show that the MICSI device may offer a clinically applicable alternative for both selecting high-quality sperm for injection into oocytes and providing a platform to do so.