(267) Development of a Tissue Slicer for Ovarian Biology Study in Large Animal Models and Humans

Levon J. Shukrian¹, Jessica Bieker², Lake Heath², Elizabeth Johnso², Skyler Waechter², Liuliang Zhang², Jing Xu¹
1. Department of Biology & Chemistry, School of Health Sciences, Liberty University, Lynchburg, VA, USA
2. Department of Mechanical Engineering, School of Engineering, Liberty University, Lynchburg, VA, USA

Abstract Text: Large animals, such as domestic animals and non-human primates, are useful models for translational study of ovarian biology, because ovaries of large animals have structure and function that are comparable to those of humans. For example, ovarian tunica albuginea and cortex are thick and dense in large animals, but are very thin in rodents. Therefore, in vitro studies of ovarian biology using large animals often require obtaining 0.5-1.5 mm fresh tissue slices. Ovarian tissue slicing is the first critical step for preantral follicle isolation, ovarian tissue culture, ovarian tissue cryopreservation, and bioprosthetic ovary construction. In the past decade, ovarian slices have been obtained using a Stadie-Riggs slicer. However, the product was discontinued years ago and there is no comparable alternative commercial product available. To meet the demand of ovarian biology research, an interdisciplinary project was conducted to develop a slicer for manual cutting of ovarian tissue. A compact slicer was built using 304 stainless steel and glass with dimensions of 14 × 15.5 × 18.5 cm, including a fully dismantlable handle. The product was designed to use Accu-Edge disposable microtome blades. All materials comply with the FDA standards regarding compatibility with human tissues. The product is capable of withstanding high temperatures (up to 132 °C) and resistant to ethylene oxide gas used during sterilization process. To test the tissue slicer, bovine ovaries were collected from the local slaughterhouse. Corpus luteum was removed. Ovarian cortex was cut into slices using the slicer. Tissue slices were fixed in 4% paraformaldehyde, embedded in paraffin, and sectioned for hematoxylin and eosin staining. Tissue morphology was examined using light microscopy. The slicer built in this project could consistently cut fresh bovine ovarian cortex into ~1 mm slices in a timely manner. Hematoxylin and eosin staining revealed condensed fibrous tissue of tunica albuginea in the first slice. Starting from the second or the third slice, primordial follicles, preantral follicles, and capillary blood vessels became evident. Follicles remained intact with typical structures. The results suggest that this slicer can achieve the goal of producing ovarian tissue slices with minimal mechanical disruption. Ovarian tissue integrity can be well-preserved for downstream in vitro study. This newly developed tool holds the potential for standardizing ovarian tissue preparation procedure which will facilitate translational ovarian biology studies using large animal models and clinical applications in fertility preservation for female patients. In addition, the ovarian tissue slicer can contribute to ovarian tissue cryopreservation of the endangered animal species and animals with special economic value.