Development of a low-cost microfluidic chip for hyaluronidase-free oocyte denudation in mammals

Infertility in mammals is one of the most intricate medical issues requiring non-traditional interventions. In Vitro Fertilization (IVF) is one of the modern medical technologies currently used to treat infertility. However, current IVF procedures are inaccessible and unaffordable to the majority due to the high cost, the complexity of the procedure, and the reliance on highly qualified operators. For successful IVF, oocyte denudation, the process of removing cumulus cells from oocytes, is often performed. Here, microfluidics offers the potential to enhance denudation procedures and to minimize operator variability. In this paper, we propose the configuration of a microfluidic chip for oocyte denudation whose structure hybridizes inner jagged surfaces and expansion units. The jagged surface units have the role of removing the cumulus cells surrounding the oocyte by using the wall shear stress principle, and the (rounded) expansion units have the role of rotating the cumulus cells for further deployment in subsequent jagged surfaces. The proposed device can be manufactured at a low cost (<1 USD)) by the engraving of CO₂ laser machine on PMMA material, and is able to circumvent the use of enzymatic components such as hyaluronidase. Experiments using computational simulations and manufactured microfluidic chips evaluated distinct geometry configurations of the jagged surfaces and identified the suitable flow rates for maximal shear stress and denudation performance. Manufactured samples of the proposed microfluidic devices have shown the denudation performance of 96.7 % and yield rate of 90 % at a constant flow rate of 1 ml/min.