To be confirmed, technique that creates the ideal biological environment for the existence of sperm may have an impact mainly on men with severe infertility.
A North American startup recently claimed to have managed to create functional human sperm in the laboratory.
The advance was claimed by Paterna Biosciencesbased in Utah, which says it has grown mature human sperm from stem cells taken from the testicles. According to the company, cited on April 23 by , these cells were then used to create embryos that appeared to be healthy.
The results have not yet been peer-reviewed or independently confirmed. But the company is focusing on a long-standing challenge in reproductive biology: understanding how to recreate outside the body the highly controlled process that allows the testicles to produce sperm. In the male body, production takes just over two months and takes place in a very specific biological environment, where cells divide, reduce the number of chromosomes to 23 and develop a tail that allows them to swim.
Alexander Pastuszakco-founder and CEO of Paterna and a urologist at the University of Utah School of Medicine, says the team was able to bypass the physical testicle. The researchers extracted stem cells capable of producing sperm and placed them in a laboratory dish, using computer models to determine the chemical signals necessary for their development.
The technique may have an impact mainly on men with severe infertility. About half of infertility cases involve male factorse Between 10% and 15% of infertile men do not have sperm in their ejaculate. In many of these cases, the necessary cells exist, but the biological environment that should allow them to mature does not function correctly. Paterna’s proposal is to recreate this environment in the laboratory and use the sperm generated for fertilization.
Experts interviewed by Wired consider the advance potentially revolutionary, but insist on the need for scientific validation. Larry Lipshultz, professor of urology at Baylor College of Medicine, highlighted that identifying the growth factors necessary for the development of these cells could represent an important step.
The work is part of a broader field, known as gametogenesis in vitrowhich seeks to create gametes — sperm and eggs — outside the body.
And the investigation goes beyond the testicles. At Oregon Health and Science University, scientists recently created early human embryos from skin cells, showing that assisted reproduction could be approaching scenarios once considered science fiction.
