ZP2 peptide beads select human sperm in vitro, decoy mouse sperm in vivo, and provide reversible contraception

The zona pellucida, a matrix that surrounds ovulated eggs, is the site of sperm recognition and binding, which precede sperm penetration and fertilization. Avella et al . identified a peptide from the zona pellucida called ZP2, which the authors attached to agarose beads to facilitate infertility treatment or, conversely, contraception. On the one hand, the beads with ZP2 peptide were combined with sperm in vitro to successfully select the best sperm for assisted reproductive technologies. On the other hand, the same beads placed into the uterus of fertile mice bound any incoming sperm and prevented them from reaching the eggs, thus providing a long-acting method of contraception. A related podcast discusses these findings.