Comparison of Fertilinβ-Peptide-Substituted Polymers and Liposomes as Inhibitors of in Vitro Fertilization

Binding an egg can be made more difficult for approaching sperm by fertilinβ-containing inhibitors. A small number of multivalent contacts are required for efficient attachment of fertilinβ-containing inhibitors to receptors on the egg plasma membrane (see figure) but the physical size of the inhibitory complex also contributes to steric blocking of sperm binding to the membrane and can block sperm from binding to a second receptor type.