Scientists have developed biodegradable and magnetic nanoparticles that, applied to male rodents, served as a contraceptive method. Although made only in rats, it could serve as an inspiration for the development of male contraceptive methods for humans in the future.
The research was published in the journal Nano Letters, of the American Chemical Society.
Scientists from the University of Nantong and the University of Shanghai, both in China, injected, for two days, doses of nanoparticles coated with citric acid in mice.
The particles were guided to the animals’ testicles with the aid of magnets and, for 15 minutes, magnetic fields were applied on the spot.
The action generated an increase in temperature in the testicles and, consequently, spermatogenesis — generation of sperm — was contained.
Animal fertility was estimated between 7 and 60 days after treatment. In addition, male mice were placed with females for seven days. After mating, the animals were separated.
According to the researchers, in the seven days that followed the application of nanoparticles and magnetic fields, the animals were unable to generate offspring. But rodents recovered 30 to 60 days after treatment.
Thinking about humans —something very far from the reality of the research tests mentioned above—, while there are several contraceptive methods for women, men basically rely on vasectomy and condoms, the latter also of great importance for the prevention of STDs (Sexually Transmitted Diseases).
There are studies developed for decades to create other male contraceptive methods, usually focused on spermatogenesis.
Male contraception does face some difficulties, however. In the case of hormones, for example, as well as in female methods, there are side effects, such as acne, variation in libido, mood changes, headache and erection difficulties, according to some studies. There is also no knowledge of the long-term effects on fertility and the latency period (how long the intervention takes to take effect).
In general, the biggest difficulty is to get a method with few side effects and that is reversible.