Male Infertility Treatment: Dr. Paul Turek’s Artificial Testicle Implant? Here’s good news for infertile men. If two scientists from San Francisco, California are successful, in about a decade, infertile men may be able to produce their own sperm and conceive children.
The two men hope to create the world’s first artificial human testicle that can produce sperm. Now with a Small Business Innovation Research grant from the National Institute of Environmental Health Sciences, they have embarked on the project, which they hope to finish in five to seven years.
Previous studies have shown scientists treating infertile male mice by producing sperm using stem cells from the mouse, but this has not been replicated in humans, said Dr. Paul Turek, one of the researchers and director of the Turek Clinic, a men’s health medical practice in San Francisco.
“You’ve seen the posts on how successful this research has been in mice models using various stem cells as a starting point: embryonic stem cells, adult stem cells and early germ line (spermatogonial) stem cells. In labs all over the world, real, live, fertile sperm have been made in animal models from each of these stem cell precursors,” Dr. Turek wrote in his blog.
“Fertile sperm can be made from various stem cells in mice, but making human sperm from these same sources has been elusive,” he says.
Other researchers have also tried to grow sperm from cells in lab dishes but the cells wouldn’t complete all the steps, according to Dr. Turek. Inside testicles, cells go through about 12 stages before they become functioning sperm. But in a Petri dish in a laboratory they stop at stage 9 or stage 10 — they can only complete the process in the highly specialized environment of the testicle.
Putting the two findings together, Dr. Turek and his fellow researcher, Dr. Constance John, chief executive of MandalMed Inc., a biotech company in San Francisco, hope to develop what they call a human “sperm-making biological machine” with the NIEHS grant. Such grants are typically less than US$500,000, Dr. Turek said.
In their project, the two scientists will try to produce mature human sperm in a live laboratory model of a human testicle.
Basically, Dr. Turek said his colleague, Dr. John, want to “re-create the testicle in an artificial environment, with all of its components.” They are to re-create the environment within the seminiferous tubules, the structures in the testes where sperm are formed.
For their male infertility treatment project, the researchers will begin by growing Sertoli cells and other cells that normally nurture sperm during their development. The researchers will then add embryonic stem cells, which can turn into virtually any cell in the human body. “Fortified” with genes, the stem cells will develop the properties of sperm precursor cells, Dr. Turek said.
The hitch? The artificial testicle would likely last about 70 days — the time it takes to go through one cycle of sperm production, Turek said. After that, another one would have to be created.
Another thing is that the artificial testicle will mimic the testicle’s environment but won’t look like one at all: Unlike a non-sperm-producing prosthesis—a saline-filled or silicone implant for men missing a testicle — the device Turek’s group will create will look like a cylindrical bag that’s a few inches long. It will look like a transparent, over-sized Tootsie Roll, he said.
Ambitious science for human good
“It’s an ambitious project,” said Kyle Orwig, an associate professor of obstetrics, gynecology and reproductive sciences at the University of Pittsburgh who studies ways to restore male fertility.”
No one has yet tried to create sperm by re-creating the “home” of sperm cell production and adding stem cells, Orwig said.
“It would be fantastic if it happened. It would be a major impact on the fertility field,” he said.
In time, it might be possible to use the same model to produce sperm for men who are infertile. But to do this, the researchers would have to use adult stem cells from the patient rather than embryonic stem cells. According to Turek, such cells can be taken from the patient’s skin, and researchers would have to “turn back the clock” so the cells could develop into sperm.
But if this male infertility treatment would work still remains to be seen, Turek noted.
The project extends on Dr. Turek’s previously published research on human testicular stem cells, the forerunners of sperm. In turn, Dr. John is an expert on human Sertoli cells, which critically nurture sperm as they develop in the testicle.
Dr. Turek, who is not associated with any academic institution, says he is motivated by wanting to help infertile men. “Personally, feeling the suffering of patients with infertility is far more motivating than doing science for the sake of science, or for the sake of tenure,” Dr. Turek said.
“It feels absolutely fabulous to be able to dream it, write it and finally to do it: The essence of science for the good of people,” he said.
Male Infertility Treatment: Dr. Paul Turek’s Artificial Testicle Implant? Posted 22 January 2012.