Turek on men's health
U.S. News Top Doc

Award-winning urologist - and pioneer in Men's Health - Dr. Paul Turek blogs weekly about issues such as infertility, vasectomy and vasectomy reversal, sexual and hormonal dysfunction and more. Keep up with the latest on this fascinating field of medicine.

The Artificial Testicle: Centuries in the Making



An ancient homunculus drawing from the 17th century
Who is that tiny person in that homunculus?

As I was preparing a recent lecture on Artificial Sperm from Stem Cells for the annual meeting of British urologists, a thought struck me. By no means in pornographic way, the biology of male reproduction has fascinated me for over 20 years. This is different from the usual, casual interest that many men have with their “stuff” since waaaay back when.

Just Add Water

Believe you me, I am not the first to be fascinated by this subject. In fact, Paracelsus first coined the term homunculus in the 15th century when referring to sperm. At that time, it was thought that sperm contained a tiny, but fully formed man or woman just waiting to burst out and grow in the womb. Just add water. This early theory of heredity was termed preformationism for you crossword puzzle buffs.

Then, a century or so later, came Leeuwenhoek. An uneducated tradesman with a keen eye, he created a neat little “microscope” that magnified things 200 fold, and was the first to observe a moving sperm. Incidentally, he was also the first to discover bacteria after looking at the plaque on his teeth. What else was there to do in 17th century Holland?

Turek the Tinkerer

Admittedly a minor leaguer compared to these august figures, I became fascinated by sperm while in medical school. How can these cells, developing well after the immune system has a firm grip on the body, not be rejected by the body as “foreign?” Is this the reason why testicles are walled off from the rest of the body and kept outside of it in a scrotum that is 3 degrees cooler than core temperature? Maybe. We still don’t know for sure.

Fast-forward to my surgical residency training at Penn in the roaring 80s. Still pondering the immunology of sperm, I did bench-top research with Dr. Donna Peehl at Stanford and published a paper about human Sertoli cells, the nurse cells that line the sperm-producing tubules in the testicle. I discovered that Sertoli cells actually do communicate with the body’s immune system, convincing me that the testicles were not simply a “stealth” organ unnoticed by the body. The body clearly “knows” that they are there and that there is foreign sperm within them, but somehow (thankfully) it chooses not to react to them. We still haven’t fully explained how these systems can peacefully coexist.

Creating an artificial human testicle, the topic of my lecture in England, has been a long, hard road to date. Yes, some day, with further persistence and inspiration, we might spin out sperm from a variety of stem cells after using this device. But, this little-engine-that-could may also help us unravel many of the mysteries of sperm biology that have eluded us for generations, nay centuries. In the words of John Lien, the “Whale Professor” at St Johns University, “…the black right whale has 4 kilos of brains and 1,000 kilos of testicles. …we know what it is thinking about!”


22 Responses to “The Artificial Testicle: Centuries in the Making”

  1. Jr

    I randomly came across a Morgan freeman special last week, which had a segment by Rena Pera, who discussed her stem cell sperm work, using the new technology discovered in 2007. It seemed very encouraging.

    Reply
  2. Skylar

    Dr. Turek, what can I do to get involved with your research on the Artificial Testicle? My wife and I were completely devastated when we learned about my azoospermia. I am willing to do whatever is necessary to find the answers we need to have children. I’ve already had a consult with you, but when I stumbled upon this I felt like there may be a chance. Please and thank you!

    Reply
    • Paul Turek, MD

      Skylar, what you can do to help is to keep up your hope and be the best person you can be in what must be emotionally trying times. Take care of each other. And realize too that popular support of scientific quests has always mattered to its success.

      Reply
  3. Josh

    Dr Turek, please keep up your work on the artificial testicle. I am very interested in your research. I am 27 years old and have lost 1 of my testicles to cancer and due to radiation treatment I am sterile. Your research for people like me gives hope.

    Reply
    • Paul Turek, MD

      Josh, having a “sterile” ejaculate and becoming a biological father are quite common in my practice. Currently technologies, such as FNA Mapping, might be of help now. But, I promise to continue the artificial testicle/sperm research in any case.

      Reply
  4. Jr

    Dr. Rena Pera said the artificial sperm is going to be for infertile men who want to have a biological child with their wife. She said she has to explain this to people who are not happy that the new technology may be used for perceived immoral purposes, such as creating sperm from a women’s stem cells, which may not even be possible since a woman lacks a Y chromosome, I think the popular message has to stay this way and not veer off course, at least for now.

    Reply
    • Paul Turek, MD

      Ash, great question! A man’s genetics do not change in spite of gender conversion, so taking skin cells to make adult stem cells (IPSs) to make sperm should work in every genetic male. Not sure about making sperm from women’s skin cells though. Never been done.

      Reply
  5. Adrian

    Dr Turek,

    How possible is it that an injection of adipose derived stem cells into a testicle, can replenish or regenerate the testosterone secreting cells? What’s your opinion?

    Thanks for your help

    Reply
    • Paul Turek, MD

      Adrian, adipose (fat) is a source of adult stem cells. They may be plastic enough to form other cells, like testosterone-producing cells of the testicle, but only time will tell. Currently, this research is no where near rigorous enough for clinical use (i.e. treating patients). For example, do fat derived stem cells cause any cancer or other issues when placed outside their normal environment?

      Reply
      • Adrian

        Thank you doctor Turek,

        The reason I ask you is because I experienced trauma to the testicles and they shrunk. I got my t levels checked out and there’s been quite a decrease. I noticed that the last time I went on an anti oestrogen T booster supplement my testicles seemed to get bigger. I have asked regular urologists if there is any way to return testicle size permanently and they have turned around and said they don’t know, or to go see an endocrinologist. In your expertise, do you know of any way to increase testicle size/ leydig cell number? Maybe some anti estrogen or testosterone booster?

        Thank you very much for your time and help.

        Reply
        • Paul Turek, MD

          Adrian, It is very difficult to return failing or atrophic testicles to their normal size. I would imagine that stem cell therapy would have the most potential to do this in the future. Remember, though, that 80% of testis volume consist of sperm producing cells. So, by increasing testosterone producing cells (Leydig cells), testosterone may increase but I would not expect testis volume to change noticeably.

          Reply
  6. kelsee McClellan

    My bestfriend lost both of his testicles while serving in Iraq. Hes only 20….what is the possibility for him ever having his “own” children. ?

    Reply
    • Paul Turek, MD

      Wow Kelsee! Tough call. But I would say it will happen in his lifetime.

      Reply
  7. G khan

    I want a biological father of my child, but i dont have sperm how it’s possible?

    Reply
    • Paul Turek, MD

      Well, Gkhan, please ponder this question first: How do you know that you don’t have sperm?

      Reply
  8. JH

    Hi Dr Turek
    First of all I am very pleased with your work and efforts and I believe you are hope for many men like me. I was diagnosed with Azosperima in 2008 . I had my PESA/TESE biopsy , they didnt find any sperm their as well. doctor said i have smaller set of testicles , Is there any trement for my case.

    Thanks

    Reply
    • Paul Turek, MD

      JH, there may very well be treatment. Again, if the problem is one of low sperm production, than a PESA procedure does not generally find sperm as it samples the epididymis, not the testicle. Therefore, this procedure has no impact on the ability to find testis sperm. If the TESE procedure sampled only one, two or 3 sites, then more extensive sampling of the testis with minimally invasive techniques such as FNA Mapping could find sperm. Smaller testicles have very little impact on the ability to find sperm. FSH levels also don’t matter all that much, no matter how high they are. Give us a shout and we can talk more!

      Reply
  9. teddy

    Hi Dr Trek,
    I have undecided testicles and I am now 39 years old, because of the size and the place one of the testicle it has been removed by surgery so now I have one testicle and still not in down completely , is any way or chance for me to have my biological child? Really desperate to know my fate, it has been very big challenge with my wife.
    Thanks Dr.

    Reply
    • Paul Turek, MD

      Dear Teddy, I am speaking at Pediatric urology congresses to let them know to KEEP undescended testicles around and to NOT take them out. If they are present, then there is a chance, but if they are not, there is definitely no chance of having kids. Consider a call to talk more.

      Reply

Leave a Reply

What is 5 + 12 ?
Please leave these two fields as-is:
IMPORTANT! To be able to proceed, you need to solve the following simple math (so we know that you are a human).

Proud Chair, Medical Advisory Board

Clinic by the Bay is a locally funded, volunteer-powered primary care clinic in San Francisco that tries to meet the needs of our friends and neighbors who are medically underserved. We need your support to operate. Please consider giving.

Subscribe to RSS Feed

Associations