P-259 Intracytoplasmic sperm injection conducted within a micro 3D printed device that requires no holding pipette or vacuum reduces porcine oocyte invagination during microinjection

Abstract Study question Can the use of a custom-designed and 3D printed microICSI™ device reduce degree oocyte invagination during intracytoplasmic sperm injection (ICSI)? Summary answer Invagination was significantly less in porcine oocytes when ICSI performed compared to conventional ICSI. What is known already difficult procedure for embryologists master, yet until recently, technically little had changed. In particular, holding pipette (HP) with vacuum hold has not been surpassed. However, source shear-stress zona pellucida cytoplasm that occurs microinjection, due pressure against small surface area HP. A recent study demonstrated microinjection within two-piece device. Here we evaluated design refinement displaced more evenly across improve embryo quality. design, size, duration control (conventional ICSI) group (microICSI™) were over three replicates investigating level (3-point score, 1 lowest 3 greatest) Incidence cytoplasmic lysis also recorded 24 h following Participants/materials, setting, methods Porcine collected by follicle aspiration abattoir-sourced ovaries matured 39-44 NCSU-17 medium supplemented eCG, hCG, follicular fluid, EGF insulin. Mature oocytes, stripped cumulus, randomly allocated either or microICSI™. performed, treatment order randomised, injected cultured culture at 39 C. Main results role chance The modelled as one-piece structure contoured surfaces microwell array support without requirement pipette. Two-photon polymerisation micro printing used print assess multiple prototype geometries optimise Over (n = 10-20/treatment/replicate), consistently lower (Mean ± SEM): Replicate 1: 1.40 0.16 vs. 2.00 0.19; 2: 1.20 0.11 0.13; 3: 1.42 0.12 1.78 0.15, paired t-test showing significant difference between two groups (p 0.035). incidence different treatments (ranging from 15-20% both varied replicates). Limitations, reasons caution model may sufficiently replicate what human experience greater levels (typically scored out 4 rather than 3). Wider implications findings Reducing process reflect stressful procedure, improvement fertilization rates Trial registration number applicable