Presently, the only means by which IVF patients suffering from certain types of male-factor infertility and lesbian couples can achieve a pregnancy is sperm donation. This, however, might change, thanks to the efforts of specialists from Cambridge University, who are working on creating artificial sperm.
Scientists have already created a healthy litter of mice from sperm produced from stem cells back in 2016, but until now attempts to replicate these results with human stem cells proved elusive – while cells visually resembled sperm, they lacked the capability to fertilise oocytes. The main issue was the time it took germ cells to develop into sperm cells (via a process called meiosis): approximately 8 weeks in humans compared to only 13 days in mice.
British experts, however, believe they’re halfway to solving the problem. To facilitate the process of turning stem cells into sperm, researchers used “gonadal organoids” – tiny artificial testes made from lab-grown gonadal cells. These testes provide the stem cells with appropriate biological clues necessary for them to develop into sperm cells, including going through a vital process called “erasure” during which environment-related parental DNA alterations are stripped away.
The researchers have so far gotten halfway through the process – to 4 weeks and the initial signs look encouraging. They cannot, however, at this stage, guarantee with 100 per cent certainty that the experiment will be a success. According to project head Prof Azim Surani, it is vital to ensure that all the processes occur as they would with natural sperm production for artificial sperm to be useful.
And while clinical applications are still some distance away, experts hope that someday the new technology will help alleviate the sperm shortage affecting many Western countries. For example, UK’s National Sperm Bank has been shut down having received just 7 donations in the two years; the average waiting period for a sperm donation in the country is 20-28 months.