1973–1976: first start on research career After Cambridge, Aitken started a postdoctoral position at the
University of Edinburgh's Institute of Animal Genetics,
WHO mission In late 1975, Aitken was invited to study problems associated with fertility regulation at the
World Health Organisation (WHO)'s Human Reproduction Unit in
Geneva. Returning from the WHO informative sessions, he worked as a postdoctoral fellow at the
University of Bordeaux for 1 year In 1977, Aitken had been appointed to the first Medical Research Council Centre for Reproductive Health at University of Edinburgh, where he and his team focused on the
biochemistry of implantation. Despite early achievements, his team had suspended all research activities due to material shortage from
gynaecology wards. With this transition in research styles, he could gain direct access without relying on his clinical colleagues' supply, Aitken remained at the University of Edinburgh for most of the 1980s to 1990s. It was there that he discovered an abnormally free radical attack in failures of fertilisation and later did research on the relationship between reactive oxygen species and their effects on impaired sperm function. He also proposed new techniques in contraception that had helped prevent sexually transmitted diseases and treat male infertility. These contributions laid the foundation for the reproductive studies done in the latter half of the twentieth century and later.
Oxidative stress During the time at the University of Edinburgh, Aitken worked with multiple antibodies to analyse their effects on fertilisation and human sperm function. When he gave the administration of
A23187 to spermatozoa from normal fertile and
oligospermia, he discovered a decline in fertilisation rates at a higher dose, which reduced sperm motility. In attempt to explain the cellular basis of defective sperm function association in a 1987 paper in the
Journal of Reproduction and Fertility, he found a sudden burst of production of
reactive oxygen species (ROS) associated with the free radical attack in
male infertility. The hyperactive production of ROS causes
peroxidative damage to the sperm plasma membrane, which is known as
oxidative stress, resulting in loss of sperm function. Aitken's paper had expanded on the molecular modifications of oxidants in male infertility and resulted in new therapeutic intervention methods to maintain reproductive function.
Contraceptive vaccine Besides discovering oxidative stress, Aitken also improved the male
contraceptive vaccine in later years. This research provided the foundation for designing a long-lasting and reversible form of contraceptives, providing an effective method to help prevent sexually transmitted diseases and control the world's growing population.
1998–2004: emigration to Australia The University of Cambridge awarded Aitken a
Doctor of Science (ScD) in 1998 to recognise his achievements in gamete biology. At the same time, he got a phone call from the
University of Newcastle, inviting him to take up the Chair of Biological Sciences. He first declined because he mistook Newcastle for
Newcastle upon Tyne, but then agreed after learning that the university is in Australia. since 1998. While serving high positions at the University of Newcastle, Aitken continued his research career on the reproductive studies. He and his colleagues conducted further research on the effects of oxidative stress on the physiological and functional integrity of human sperm. They also researched related oxidative stress problems, such as genetic alterations in male infertility, which culminated in
gene mutations, discussing the possible health issues of the next generation from couples using
assisted reproductive technology. He and his colleagues continued to research safe and reliable contraception vaccinations for controlling human fertility. Their study included developing the potential contraceptive potential of
ZP3 peptides and other chemical compositions of these contraceptive agents, implying the potential effectiveness of the anti-hCG antibodies. During his early years in Australia, Aitken attempted to diverge his studies from human reproductive science. In addition, he discovered
Ehrlichia platys in dogs in Australia, which had not previously been found in Australian animals. However, after few years, he decided to return to andrology and the pursuit of understanding the
cell biology of
spermatozoa. During this time, Aitken and his team carried out some studies to identify different causes affecting male reproductive health. They found that environmental conditions such as smoking, toxins, and mobile radiation contribute to various health issues. These not simply affect male fertility by causing oxidative stress, but they also cause DNA damage, increasing the risk of a man's children developing infertility or cancer. Despite not gaining much success in the animal study, his contribution to developing immunocontraception on animals ranging from horses, sub-mammalian organisms to annelid worms, oysters, and fish enabled the development of a nonsurgical sterilization technique. In 2015, he received a patent for his "Method for reducing the Reproductive Potential of an Animal" while working with
Eileen McLaughlin. His invention revolutionized Australian horse breeding industry, which provided a new method of controlling the horse population and increase their value.
2018–current In more recent years, Aitken has been focusing on translational research in male contraception and male infertility. Since 2016, he has been working alongside Memphasis to develop "Felix", a device which uses a patented cell separation technology to more gently and effectively separate sperm from semen samples. This project seeks to increase the collection of vital, stable sperm during the crucial early stages of the IVF process. == Awards and honours ==