A new study at Stellenbosch University (SU) shows that a safer, more effective, and reversible contraceptive for men is within reach.
Kyla Raoult, who obtained her master’s degree in Polymer Science at SU’s December graduation on Tuesday December 10, developed an on-demand reversible hydrogel that could be used as a reversible, non-hormonal birth control for men. A hydrogel is a soft jelly-like material that absorbs water and swells to form a 3D net-like network with pores.
Ms Raoult says the idea is to inject the gel into the vas deferens – the tube that carries sperm out of testicles – where it swells in response to watery bodily fluids to create a semi-permeable barrier. Once swollen, the hydrogel’s pores allow seminal fluid to pass but block the passage of sperm, as they are too large to fit through. The blocked sperm is then reabsorbed by the body, similar to what happens after a vasectomy. The gel, which forms in the vas deferens in under a minute, can be injected in a doctor’s office.
“The hydrogel is designed to stay in place until the patient wants to restore fertility. This technology could help men reduce their fertility, without the usual side effects of hormone blockers, and then restore it when they’re ready to start a family. It is important to note that the actual duration of contraception must still be studied and confirmed in clinical trials.”
Ms Raoult points out that the on-demand reversible hydrogel is based on two polymers (large synthetic molecules) that chemically react to form it. These polymers are also safe for use inside the body.
“By simply injecting a solution into the gel to reverse the process, the chemical bonds in the gel are broken, causing it to dissolve into a watery substance that can be flushed out.”
When asked what inspired her to explore this specific approach to contraception, she explains that most contraceptives are designed for females.
“Men’s options are mostly limited to condoms, vasectomies and some hormone-based methods. Condoms aren’t always 100% effective and since they are known to decrease sexual stimulation, they are often used incorrectly, if used at all.
“Vasectomies are excellent contraceptives, but their reversal often results in complications, and they are more of a permanent option.
“The hormonal options are still being tested, and their effectiveness has yet to be proven. They are also often associated with negative side effects. So, there is a clear need for a reversible, non-hormonal male contraceptive.
“Other hydrogels that are being developed rely on external massaging or vibrations to break them down, which often results in damage to the vas deferens. Our technology is designed to make reversibility quicker and easier,” adds Ms Raoult.
She says there is a growing interest among men to help prevent unwanted pregnancies.
“If our technology can provide men with a safe, one-time insertion, easily reversible option, I believe that the idea of men contributing to the prevention of unplanned and often unwanted pregnancies will be realistic. Gender equality in contraception is important as both men and women should be responsible for contributing to safer sex practices.”
Ms Raoult notes that a well-known hydrogel contraceptive called RISUG (Reversible Inhibition of Sperm Under Guidance) was developed about a decade ago in India. It was made from a polymer that is the focus of the Klumperman Research Group, led by her supervisor, Professor Bert Klumperman, from SU’s Department of Chemistry & Polymer Science.
Her project builds on previous work done in the group to make this technology better and more reversible.
Ms Raoult explains that, since the project is still in its developmental stage and needs further laboratory studies before clinical trials, it is not possible to estimate when the technology will be available on the market.
She has already started working for a US-based biotechnology company, NEXT Life Sciences, that is busy developing hydrogels for male contraception.
