NV-Centers Nanodiamonds to Study Oxidative Stress in the Male Germ Line

Nanodiamonds with structural Nitrogen-Vacancy (NV) defects can translate magnetic noise in their surroundings into easily detectable fluorescent signals. This makes them ideal sensors for short-lived free radicals produced in biological systems. Free radicals are a crucial group of Reactive Oxygen Species (ROS) whose quantification offers pivotal insights into oxidative stress-related conditions such as cancer, aging, drug response, and infertility. We use NV-centers nanodiamonds for the magnetometric detection of free radicals at a single-cell level with subcellular resolution. We have successfully applied diamond magnetometry in all the conditions mentioned above. Now, we are focused on the connection between oxidative stress, aging, and male infertility. Various socioeconomic factors have contributed to the established trend in western countries of delaying fatherhood, which is linked to reproductive problems such as subfertility, congenital anomalies, and neuropsychiatric disorders in the offspring. Studies conducted on sperm samples offer a perspective limited to the outcome of age- and oxidative stress-related mechanisms that affect spermatogenesis, completely ignoring what happens to the precursor germ cells of spermatozoa. Germ cells reside inside the seminiferous tubules of the testicles and experience complex differentiation processes that are sensitive to free radicals and other ROS. Using the D-Galactose mouse model of accelerated aging, we studied free radical production in different types of germ cells and also in Sertoli cells, the nurse cells for spermatogenesis. We think that the single-cell reporting capacity of diamond magnetometry applied for the first time to the complex scenario of the male germ line is attractive for the field of Reproductive Medicine and highlights the versatility of nanodiamonds as nanoscale biosensors.