Reversible inhibition of sperm under guidance

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RISUG (Abbreviation for Reversible inhibition of sperm under guidance ) is a non-hormonal method of contraception for men developed in India . For this purpose, a plastic gel based on styrene-maleic anhydride copolymer (SMA) is injected into the vas deferens. The adjective reversible is misleading insofar as there are no studies to date on the extent to which the procedure can be reversed in humans. The method was developed by Sujoy K. Guha at the Indian Institute of Technology Kharagpur . The preparation is in phase III clinical trials in India and is patented in India, China, Bangladesh and the United States of America (USA). In the USA the Parsemus Foundation is working on this method under the brand name "Vasalgel" and is aiming for approval by the FDA .

Working mechanism

RISUG is injected into the spermatic duct ( vas deferens ), i.e. the section of the vessel through which the male sperm cells have to pass before ejaculation . Within a few minutes, this injection coats the walls of the vas deferens with the polymer gel. This gel then damages the sperm cells flowing past in such a way that they are no longer able to fertilize a female egg cell. The method is based on the idea that sterility can be reversed by rinsing out the plastic gel by injecting the solvent dimethyl sulfoxide (DMSO) or sodium hydrogen carbonate solution .

After application to 250 volunteers, no side effects were recorded other than a slight swelling of the testicles, which some volunteers experienced immediately after the injection. Any swelling disappeared within a few weeks. Because the sperm can escape unhindered, the test subjects did not experience any pressure or granuloma formation, as can occur in vasectomy patients.

A further development of RISUG published in 2009 is an SMA gel that contains finely divided iron oxide and copper particles ( Smart RISUG): this increases the spermicidal effect, as released copper ions lead to a reduction in mobility and increased malformation of the sperm. Furthermore, after the injection, the position and shape of the gel body in the vas deferens could be corrected by applying an electromagnetic field, and removal should also be possible by liquefaction in the magnetic field.

advantages

  • Health: No hormonal stress on both partners.
  • Effectiveness: In 250 test persons, there was only one unplanned pregnancy, which was due to an improper injection. In 15 of these test persons, the procedure was more than 10 years ago.
  • In contrast to the use of condoms, RISUG does not require interruption of the sexual act.
  • Outpatient procedure: The men can leave the clinic immediately after the injection and resume their usual sex life after a short waiting period until no more sperm can be detected in the ejaculate (usually within a week).
  • Long-term effectiveness: According to the inventor Guha, a single injection should have an effect of up to 10 years.
  • Inexpensive: RISUG was developed as an inexpensive method of contraception in order to enable family planning even for poorer sections of the population. In contrast to hormonal preparations, which have to be taken regularly, only the costs for one procedure are incurred here.
  • Ecological aspects: There is no hormonal load on water from the excretion of hormonal substances (such as the birth control pill ).

disadvantage

  • The non-invasive removal after a long period of wearing the plastic gel is not guaranteed.

literature

  • SK. Guha: Contraceptive for use by male. United States patent. 1996: 5,488,075.
  • CY Cheng, DD Mruk: Male contraception: Where do we go from here? In: Spermatogenesis. Volume 1, number 4, 10 2011, pp. 281-282, doi: 10.4161 / spmg.1.4.19014 , PMID 22332110 , PMC 3271638 (free full text).
  • RK Jha, PK Jha, SK Guha: Smart RISUG: a potential new contraceptive and its magnetic field-mediated sperm interaction. In: International journal of nanomedicine. Volume 4, 2009, pp. 55-64, PMID 19421370 , PMC 2720737 (free full text).
  • Stephanie T. Page, John K. Amory, William J. Bremner: Advances in Male Contraception . In: doi: 10.1210 / er.2007-0041ne , 29 (4), pp. 465–493, PMC 2528850 (free full text)
  • Sujoy K.Guha, Vandana Chauhan, Shubhadeep Banerjee: Designed Self Assembly of Nano-Liposomes in the Male Reproductive Tract for Model Drug Delivery to the Prostate. (PDF; 1.3 MB) In: The Open Nanoscience Journal. 2011, 5, pp. 11-15 doi: 10.2174 / 1874140101105010011 .
  • NK Lohiya, B Manivannan, PK Mishra, N Pathak, SPA Balasubramanian: Intravasal contraception with styrene maleic anhydride and its noninvasive reversal in langur monkeys (Presbytis entellus entellus) . In: Contraception. 58, 1998, pp. 119-128, PMID 9773267 .
  • B Manivannan, PK Mishra, NK Lohiya: Ultrastructural changes in the vas deferens of langur monkeys Presbytis entellus entellus after vas occlusion with styrene maleic anhydride and after its reversal. In: Contraception. 59, 1999, pp. 137-144, PMID 10361629 .
  • NK Lohiya, B Manivannan, PK Mishra: Repeated vas occlusion and non-invasive reversal with styrene maleic anhydride for male contraception in langur monkeys. In: International Journal Andrology. 23, 2000, pp. 36-42, PMID 10632760 .
  • NK Lohiya, B Manivannan, PK Mishra, S Sriram, SS Bhande, S Panneerdoss: Pre-clinical evaluation for non-invasive reversal following long-term vas occlusion with styrene maleic anhydride in langur monkeys. Contraception, 71, 2005, pp. 214-226, PMID 15722073 .
  • B Manivannan, SS Bhande, S Panneerdoss, S Sriram, NK Lohiya: Safety evaluation of long-term vas occlusion with styrene maleic anhydride and its non-invasive reversal on accessory reproductive organs in langurs. In: Asian Journal of Andrology. 7, 2005, pp. 195-204, PMID 15897977 .
  • NK Lohiya, R Suthar, A Khandelwal, S Goyal, AS Ansari, B Manivannan: Sperm characteristics and teratology in rats following vas deferens occlusion with RISUG and its reversal. In: International Journal of Andrology. 33, 2010, pp. E198 – e206, PMID 19811546 .

Web links

Individual evidence

  1. ↑ K. Chaudhury, AK Bhattacharyya, SK Guha: Studies on the membrane integrity of human sperm treated with a new injectable male contraceptive. In: Human reproduction. Volume 19, Number 8, August 2004, pp. 1826-1830, doi : 10.1093 / humrep / deh332 , PMID 15192063 .
  2. ↑ RK Jha, PK Jha, SK Guha: Smart RISUG: a potential new contraceptive and its magnetic field-mediated sperm interaction. In: International journal of nanomedicine. Volume 4, 2009, pp. 55-64, PMID 19421370 , PMC 2720737 (free full text).
  3. ↑ Drug cocktail in drinking water . Spiegel Online , August 26, 2004.