French research team patents lab-grown human sperm cells

French researchers say they have patented a method to create in-vitro human sperm using stem cells harvested from infertile men.

Sperm is injected into an egg in an in vitro fertilisation lab
Sperm is injected into an egg in an in vitro fertilisation lab Wikipédia

The team at Lyon-based biotech firm Kallistem, a startup working with government lab CNRS, says their technique is a step towards solving male infertility. They say that the technology has taken 20 years to refine.

The scientists first made the announcement in May, but with the patent are now describing for the first time how it works.

The complex process   which involves recreating, outside of the human body, the fluid where sperm cells are formed in the male testes   must now be clinically tested.

The immature cells used, known as spermatogonial cells, are present in all males including pre-pubescent boys. Under normal conditions they develop into sperm cells once puberty starts.

The work has not yet been validated through publication in a peer-reviewed science journal, and it is not known whether the tiny cells are up to the job of creating babies.

The next step, the team said, is to try and give life to rats with rat sperm they have created – and to see whether the next generation are then able to reproduce.

But the team said in a statement that the technology could help treat issues affecting 15,000 young cancer patients and 120,000 men worldwide whose infertility cannot be treated any other way.

Their work "opens the way for therapeutic avenues that have been eagerly awaited by clinicians for many years," they said.

Daily newsletterReceive essential international news every morning

Keep up to date with international news by downloading the RFI app