A microfluidic device to reduce treatment time of intracytoplasmic sperm injection

Objective: To develop a microfluidic device that can reduce the intracytoplasmic sperm injection (ICSI) treatment time by increasing sperm concentration. Design: We compared the ICSI treatment time required for porcine sperm using a method employing the microfluidic device and one using the conventional microdroplet method. Settings: Academic research laboratories at Okayama University. Animal(s): Reproductive cells of porcine sperm, oocytes, and embryos. Intervention(s): Cell manipulations, ICSI, and embryo culture. Main Outcome Measure(s): Average ICSI treatment time and sperm concentration. Result(s): The average ICSI treatment time (mean ± SEM) using the method with the microfluidic device for poor-quality semen (sperm concentration, 2.0 × 10⁴ cells/mL) was significantly shorter than the treatment time using the conventional microdroplet method (265 ± 15 seconds [n = 43] vs. 347 ± 19 seconds [n = 50]). When diluted semen with a sperm concentration of 2.0 × 10⁵ cells/mL was used, no significant difference was observed between the two methods (n = 50 and n = 48). Conclusion(s): The microfluidic device can reduce the time required for ICSI treatment that is used to increase sperm concentration in poor-quality semen samples. The results suggest that this device may be clinically useful for ICSI treatment in human assisted reproductive technology.