A new study published in the journal Science Translational Medicine describes how they developed their contraceptive antibodies as an alternative to hormonal forms of female contraception .
These antibodies were 99.9% effective in trapping human sperm.
Tested on sheep
Previous research has shown that certain antibodies in some women’s vaginas can make them infertile . Last year, researchers obtained some of these antibodies from volunteers and subsequently removed the antigen-binding components. They then used those components to engineer an IgG antibody that showed a propensity to bind with sperm.
More recently, the researchers added staggered amounts of the components to the engineered IgG antibodies: 6, 8, and 10. They then injected plasmids containing these antibodies into human embryonic cells, resulting in the growth of new IgG cells with the modified components . The researchers then tested the ability of their IgG cells to attract and bind with sperm in a Petri dish, finding that they were up to 10 times better at trapping sperm than the original antibodies extracted from female volunteers.
In the second part of their work, the researchers injected solutions containing their IgG antibodies into the vaginas of several sheep. This was followed by human sperm injections. After two minutes, the researchers collected samples from sheep’s vaginas and counted how many motile sperm they could find. In doing so, they found 99.9% reductions compared to control groups.