Selection of functional sperm by using hyaluronic acid modified magnetic microbeads and an electromagnetic manipulation system.

In recent years, the incidence of infertility has increased year by year. Assisted reproductive technology (ART) is one of the effective strategies to treat infertility. In the process of ART, commonly used methods for sperm separation have shortcomings and there is still room for improvement. In this study, a functional sperm selection strategy was established based on hyaluronic acid (HA) modified magnetic microbeads (MBs) and a supporting two-dimensional electromagnetic manipulation device system. Due to the modification of HA on the surface of MBs, the HA-MBs have the ability to target and bind to specific receptors on the sperm membrane to form a sperm-MB complex. A disulfide linker was introduced to connect HA and MBs. After modifying HA and connecting it with the disulfide linker, the sperm of sperm-MBs can be released under the combined effect of hyaluronidase and reduced GSH with the disulfide bond broken and HA degraded. A two-dimensional electromagnetic manipulation system was introduced to generate a magnetic field and control the directional movement of the sperm-MB complex under the guidance of an inverted microscope. The free MBs can also be removed after the sperm is released. Furthermore, the mouse sperm selected through this strategy can achieve normal insemination via ICSI and the obtained blastocysts have normal morphology and developmental milestones. This strategy has potential to be developed into an automated screening solution for the screening of functional sperm for assisted reproductive technology.