Scientists in Canada have 3D-printed viable human testicular cells that they hope will eventually yield sperm from patients with forms of infertility that currently cannot be treated.
The team at the University of British Columbia in Vancouver has been using a 3D bioprinter to create life-size models of human seminiferous tubules – the structures inside the testicles that normally produce sperm.
Stem cells taken from an infertile patient’s testicles didn’t only survive inside the artificial tubes – they thrived and showed early signs of sperm-producing capabilities, the researchers said.
The results of the study were published last month in the journal Fertility and Sterility Science but were only promoted by UBC last week.
Why this research?
In the most severe form of male infertility, known as non-obstructive azoospermia (NOA), the production of sperm within seminiferous tubules fails, and no sperm is found in the ejaculate.
In some cases, surgery can be used to retrieve extremely rare sperm, but the procedure is only successful about half the time.
“Unfortunately, for the other half of these individuals, they don’t have any options because we can’t find sperm for them,” said UBC urology assistant professor Dr Ryan Flannigan.
Those are the patients his team is hoping to help.
The researchers performed a biopsy to collect stem cells from the testicles of a patient living with NOA.
The cells were then grown and 3D-printed onto a Petri dish into a long and hollow structure similar to the seminiferous tubules that normally produce sperm.
“We’re 3D printing these cells into a very specific structure that mimics human anatomy, which we think is our best shot at stimulating sperm production,” said Flannigan.
“If successful, this could open the door to new fertility treatments for couples who currently have no other options”.
His team found 12 days after printing that the cells placed inside the tubes had survived.
Better yet, they had grown into several of the specialised cells involved in sperm production and were showing a significant improvement in so-called spermatogonial stem cell maintenance – both early signs of sperm-producing capabilities.
“It’s a huge milestone, seeing these cells survive and begin to differentiate. There’s a long road ahead, but this makes our team very hopeful,” Flannigan said.
The team is now working to “coach” the printed cells into producing sperm. To do this, they will expose the cells to different nutrients and growth factors and try to help cells better interact with each other.
If they can get the cells to produce sperm, these could potentially be used to fertilise an egg by in vitro fertilisation (IVF), providing struggling couples with a new treatment option.
But even if the cells don’t reach that stage, it’s hoped the research will help the team identify what is blocking the patient’s sperm production, and treat him accordingly.
“We’re taking a personalised, precision medicine approach – we take cells from a patient, try to understand what abnormalities are unique to them, and then 3D print and support the cells in ways that overcome those original deficiencies,” Flannigan said.