For the first time... a new treatment for infertile men using stem cell transplantation

A new treatment offers hope for men who have lost their ability to produce sperm, such as cancer survivors or those with genetic disorders, through the first clinical trial using sperm stem cell transplantation.

Scientists conducted the first clinical trial of sperm stem cell transplantation (SSC), which involves extracting sperm stem cells and re-implanting them into the testicles to stimulate sperm production, according to Interesting Engineering.

Infertility Treatment

"If this technique is refined and proven safe, SSC transplantation could be a revolutionary technique for restoring fertility in men who have lost the ability to produce sperm," Dr. Justin Homan, assistant professor of urology at Cedars-Sinai Medical Center, who was not involved in the study, told Live Science.

In the United States, approximately 645,000 men between the ages of 20 and 50 are diagnosed with azoospermia, the medical term for the absence of sperm in their semen.

Restoring Fertility

Sperm are made from sperm stem cells—present in the testicles even before puberty—and mature after testosterone levels rise. However, medical conditions and treatments, such as chemotherapy, can damage the cells, resulting in the complete absence of sperm stem cells and infertility.

Doctors can surgically extract stem cells from the testicles via a needle inserted into the rete testis—a collection of small tubes within the testicle—and then freeze these cells. The sperm stem cells can be reintroduced later in a similar manner.

Researchers hope that these cells will eventually collect in the seminiferous tubules and begin the process of sperm formation once they are reintroduced into the body.

Encouraging results on animals... and the first human trial

Previous experiments on mice and monkeys have shown remarkable success, with normal offspring being born after the transplant.

In humans, a man in his early twenties underwent the procedure using cells preserved from his childhood before undergoing chemotherapy for bone cancer.

So far, results indicate no damage to testicular tissue and stable hormone levels, although sperm have not yet appeared in the semen.

Challenges and Risks

Despite the positive signs, the technique faces several challenges:

Low number of transplanted cells: This could result in limited sperm production.

Risk of genetic mutations: Especially in cancer patients, which could increase the likelihood of tumor formation.

Immune response: Even if the transplanted cells are from the patient's own body.

Ethical questions: Regarding the storage of stem cells in young children without the actual capacity to give informed consent.

Future Outlook

Dr. Homan emphasizes, "We must proceed with caution and under close supervision. This is a promising technology, but it is still in its early stages."

If future trials prove effective and safe, sperm stem cell transplantation may represent a promising future for men who wish to reproduce after losing their fertility.