Dozens of sperm surrounding an egg

Could Magnetic Nanoparticle Selection lead to Sex Selection in IVF?

This may be a future reality.  Already, magnetic nanoparticles are utilized by some U.S. IVF Centers for deselection of unhealthy and DNA damaged sperm prior to sperm injection for fertilization. This methodology had its first use in veterinary medicine and today research is on-going in equine to evaluate the use of magnetic nanoparticles for the use of sex selection.  One of the researchers, Henry Clemente, was critically involved in developing the process of sperm selection with magnetic nanoparticles that MCRM Fertility currently utilizes. Henry was a recent guest for a Focus on Fertility podcast discussing these very topics.

Currently, cell sorting is utilized to separate spermatozoa containing either the X or Y chromosome based on DNA.  However, this technique poses several challenges through the processing, freezing/thawing, and insemination procedures.  Thus, new methods have been developed to acquire a quality subpopulation of sperm.  Successful collection of sperm with better cryo-preservation endurance and fertilization likelihood for assisted reproduction in humans has been successful through Magnetic nanoparticles (MNPs).

Sexing by Magnetic Nanoparticles begins with painstaking measures to collect the semen.  Each sample is then frozen through standard protocols and evaluated for the efficiency of the sex-sorting and viability.  Next, mobility parameters are established, and capacitation is evaluated by 2 separate techniques, pharmacologically induced acrosome exocytosis and protein tyrosine phosphorylation.  Once they were able to asses the level of DNA fragmentation, the data collected could be analyzed and verified.

Observations were made that sperm physiology is significantly affected by the cell sorter, in contrast to the MNP procedure which provided an aggregation of X containing sperm that was mobile, viable, uncapacitated similar to control samples.  However, preliminary experimentation on stallions using sperm sexed by MNP’s does not affect the result of artificial insemination with great significance.

Though either technique is similar in its effectiveness of selecting X spermatozoa, it was found that MNP is lower in cost and higher in ease and speed.  At present, these findings are mainly being applied to the donkey’s milk industry but it is another step forward in making sex selection in IVF a possibility.

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