A compact, high-throughput semi-automated embryo vitrification system based on hydrogel

Research question What is the efficiency and efficacy of the novel Biorocks semi-automated vitrification system that based on hydrogel? Design An experimental laboratory comparative study utilizing both mice models and human Day 6 blastocysts. Results The Biorocks system successfully automated solution exchanges during the vitrification process, achieving a throughput of up to 36 embryos/oocytes per hour, thereby indicating a significant improvement in efficiency. Utilizing hydrogel as the cryoprotective agent (CPA) delivery method, it was able to process 12 vessels simultaneously, fitting comfortably within an ART workstation. In tests involving cryopreservation of oocytes and embryos, the system yielded outcomes equivalent to the manual Cryotop method. For example, for mice oocytes, the Biorocks vitrification system (n = 46) gave a 98% survival rate and the manual Cryotop method (n = 39) gave 95%, and of which 46% and 41%, respectively, progressed to blastocysts on Day 5 after IVF. The outcome of CC grade Day 6 human blastocysts processed with the Biorocks system (n = 39) gave a 92% 2h re-expansion rate, which was also equivalent to 90% of the manual Cryotop method (n = 30), indicating the system's effectiveness in handling different biological materials. The cooling/warming rates achieved by the Biorocks system were 31,900°C/minute and 24,700°C/minute respectively. Conclusions The Biorocks semi-automated vitrification system offers enhanced throughput without compromising the survival and developmental potential of oocytes and embryos. This innovative system may aid in increasing the efficiency and standardization of vitrification in assisted reproductive technology clinics. Further investigations are needed to confirm its efficacy in a broader clinical context.