A microfluidic approach to rapid sperm recovery from heterogeneous cell suspensions

Steven A Vasilescu,Shayan Khorsandi,Reza Nosrati,Lin Ding,Majid Ebrahimi Warkiani,Sajad Razavi Bazaz,Debra Gook

doi:10.1038/s41598-021-87046-9

Abstract

The isolation of sperm cells from background cell populations and debris is an essential step in all assisted reproductive technologies. Conventional techniques for sperm recovery from testicular sperm extractions stagnate at the sample processing stage, where it can take several hours to identify viable sperm from a background of collateral cells such as white bloods cells (WBCs), red blood cells (RBCs), epithelial cells (ECs) and in some cases cancer cells. Manual identification of sperm from contaminating cells and debris is a tedious and time-consuming operation that can be suitably addressed through inertial microfluidics. Microfluidics has proven an effective technology for high-quality sperm selection based on motility. However, motility-based selection methods cannot cater for viable, non-motile sperm often present in testicular or epididymal sperm extractions and aspirations. This study demonstrates the use of a 3D printed inertial microfluidic device for the separation of sperm cells from a mixed suspension of WBCs, RBCs, ECs, and leukemic cancer cells. This technology presents a 36-fold time improvement for the recovery of sperm cells (> 96%) by separating sperm, RBCS, WBCs, ECs and cancer cells into tight bands in less than 5 min. Furthermore, microfluidic processing of sperm has no impact on sperm parameters; vitality, motility, morphology, or DNA fragmentation of sperm. Applying inertial microfluidics for non-motile sperm recovery can greatly improve the current processing procedure of testicular sperm extractions, simplifying the fertility outcomes for severe forms of male infertility that warrant the surgery.

Highlights

Epididymis, followed by intracytoplasmic sperm injection (ICSI)
The two most common surgical approaches taken in use are Microdissection Testicular Sperm Extraction and Testicular Sperm Aspiration (TESA)
We have developed a 3D printed inertial microfluidic device as a viable alternative for sperm isolation from mixed cell suspensions

Summary

Introduction

Epididymis, followed by intracytoplasmic sperm injection (ICSI). The two most common surgical approaches taken in use are Microdissection Testicular Sperm Extraction (mTESE) and Testicular Sperm Aspiration (TESA). For men who undergo testicular surgery due to azoospermia, we have developed a microfluidic, 3D printed sperm separation device This technology allows technicians to recover sperm from biopsied tissue suspensions within 5 min, effectively eliminating the human error associated with extended sample microscopy. By limiting their time in vitro and their exposure to reactive oxygen, digestive enzymes, and cellular debris, this method reduces the potential for harmful sperm exposure and allows technicians to distribute their attention to other valuable tasks in the ART workflow This setup may prove useful in the isolation of sperm and or spermatogonial stem cells from peri and prepubertal leukemic males for fertility preservation or in the purification of semen samples presenting pyospermia (high white cell contamination in semen)

Methods

Results

Conclusion