A reversible male contraceptive, targeted to the testes with magnets


Date:
July 28, 2021
Source:
American Chemical Society
Summary:
Women have several choices for long-lasting, reversible
contraceptives, but most options for men are either single-use, such
as condoms, or difficult to reverse, like vasectomies. Now, in a
step toward a safe, long-lasting and reversible male contraceptive,
researchers have developed magnetic, biodegradable nanomaterials
that reduced the likelihood of mice fathering pups for at least
30 days.



FULL STORY ========================================================================== Women have several choices for long-lasting, reversible contraceptives,
but most options for men are either single-use, such as condoms, or
difficult to reverse, like vasectomies. Now, in a step toward a safe, long-lasting and reversible male contraceptive, researchers reporting in
ACS' Nano Letters have developed magnetic, biodegradable nanomaterials
that reduced the likelihood of mice fathering pups for at least 30 days.


========================================================================== Elevated temperatures, which can be caused by wearing too-tight pants
or underwear, can decrease sperm count in men. Some researchers have
explored the more intense heating of nanomaterials injected into the
testes as a form of male birth control. However, the injection can be
painful, the heating can damage skin, and most nanomaterials tested so
far are not biodegradable. Weihua Ding, Fei Sun and colleagues wanted to develop a safe, effective magnetic- thermal approach to male contraception
that doesn't need to be injected directly into the testes.

The researchers tested two forms of iron oxide nanoparticles, which are biodegradable and can be guided and heated with magnetic fields, as male contraceptives. One type of nanoparticle was coated with polyethylene
glycol (PEG) and the other with citric acid. Although the PEG-coated nanoparticles could be heated to higher temperatures, they were not as
easily manipulated by magnets as the other ones. So the researchers
injected repeated doses of citric acid-coated nanoparticles into the bloodstream of mice for 2 days, guided the nanomaterials to the testes
with magnets, and then applied an alternating magnetic field to the area
for 15 minutes. The nanoparticles heated the testes to a temperature
of 104 F, shrinking them and inhibiting spermatogenesis before gradual
recovery 30 to 60 days after treatment. The mice couldn't father any
pups 7 days after treatment, but they were back to fathering about 12
pups per pregnant female at day 60. The nanoparticles were non-toxic
to cells and were gradually eliminated from the body, offering new possibilities for male contraception, the researchers say.

========================================================================== Story Source: Materials provided by American_Chemical_Society. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Weihua Ding, Zhichuan Chen, Yayun Gu, Zhengru Chen, Yanqiong
Zheng, Fei
Sun. Magnetic Testis Targeting and Magnetic Hyperthermia for
Noninvasive, Controllable Male Contraception via Intravenous
Administration. Nano Letters, 2021; 21 (14): 6289 DOI:
10.1021/acs.nanolett.1c02181 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/07/210728105602.htm

--- up 11 weeks, 5 days, 22 hours, 45 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)