A reversible male contraceptive, targeted to the testes with magnets

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.