Investigation of the Effect of Physical Injection Parameters on Biological Cell Deformation

Intracytoplasmic Sperm Injection (ICSI) is an assisted reproductive technology in which the zona pellucida and the cell membrane (oolemma) are pierced by a micropipette and a sperm is injected into the cytoplasm for fertilisation. However, cell damage is often spotted during the penetration process mainly due to oocyte deformation, which may lead to oocyte degeneration. Cell injection parameters are the main contributing factors to the cell damage, which may cause cell degeneration. In this study, the effects of injection speed and pipette diameter as two key physical injection parameters were investigated using a motorised micro injection system and zebrafish embryo as the biological model. It was demonstrated that the deformation increased from low to medium injection speeds, however, it subsequently decreases from medium to high speeds. It was successfully shown that tip diameter of the injection pipette is a contributing factor in cell deformation as the deformation ratio increased when a larger tip diameter pipette was used. The deformation is a potential damage to biological cells which may contribute to cell degeneration post injection.