Gel for male contraception
Vasagel (Vasalgel) is a polymer with a large molecular weight, developed by the Parsemus Foundation as a non-hormonal male contraceptive with a long-term potentially reversible effect. It is injected into the vas deferens and blocks the passage of sperm. The results obtained in experiments on rabbits indicate the high prospects of a new approach to male contraception.
Currently, men have a small number of methods of controlling their reproductive function. The most popular of them is the use of condoms, which, when used correctly, provide protection against sexually transmitted infections and reduce the risk of unwanted pregnancy by up to 18%. The most effective but irreversible approach to male contraception is vasectomy, which consists in excision of the vas deferens.
Every year, more than 85 million unwanted pregnancies are registered worldwide, which indicates a serious need for new methods of contraception. The results of international surveys indicate that the majority of men do not object to the use of new methods of male contraception, with variations due to demographic and cultural characteristics. Over the past decades, researchers have proposed several potential methods for regulating male reproductive function, but none of them has yet appeared on the market, which is mostly due to financial and regulatory difficulties. Moreover, until now, work has been carried out mainly on hormonal approaches, even though due to the likelihood of hormonal side effects and safety issues, most men tend to non-hormonal methods.
The results obtained in experiments on rabbits indicate that Vasagel, which is a polymer of styrene-alt-maleic acid dissolved in dimethyl sulfoxide (DMSO), is quite capable of filling an empty niche of a long-term method of male contraception.
Researchers working under the guidance of Professor Donald Waller from the University of Illinois at Chicago tested two versions of Vasagel, one of which contained 100% styrene-alt-maleic acid, and the second – a combination of 80% styrene-alt-maleic acid and 20% anhydride (dehydrated form) styrene-alt- maleic acid. 29-36 days after administration of the drug into the vas deferens of rabbits and during the subsequent follow-up period of 12 months, 11 of the 12 animals had completely no sperm in their sperm. Several sperm samples from one rabbit contained a small amount of sperm, after which he also developed azoospermia. The two tested versions of the drug had the same efficacy. At the same time, the reaction from the tissue of the vas deferens was weakly expressed and corresponded to a normal reaction to a foreign body.
According to the authors, Vasagel turned out to be even better than they expected, which is most likely due to its characteristics. After introduction into the vas deferens, the Vasagel material forms a hydrogel, which retains its soft gel-like consistency, ensuring its ability to shrink and fit snugly to the walls of the ducts. Moreover, the structure of the hydrogel allows the passage of water and many molecules soluble in it, but does not allow larger structures, such as spermatozoa, to pass through, which provides a contraceptive effect without significantly increasing the hydrostatic pressure in the appendages of the testicles and ducts, inside which the formation and accumulation of spermatozoa occurs.
The diagram shows the change in sperm concentration
after implantation of Vasagel into the vas deferens of 12 rabbits.
Unfortunately, it's not worth rejoicing yet: in this study, the reversibility of azoospermia after washing the vas deferens from the gel was not checked, and Wikipedia says about this method, among other things, that clinical studies on volunteers in India were stopped in 2002 due to suspicions about the nephrotoxicity of dimethyl sulfoxide (although they started again in 2011), and the recovery procedure was only tested on primates and "she had repeated success." What is "repeated", it is not said, there is no link...
Article by Donald Waller et al. Azoospermia in rabbits following an intravas injection of Vasalgel is published in the journal Basic and Clinical Andrology.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru according to EurekAlert!: Non-hormonal male contraceptive Vasalgel™ has proven efficacy in rabbits.
01.04.2016