Last year there was a funny picture of Fertilization on the Internet: if you complain about the hardships of life, you shouldn't take the first place in that swimming competition.
Recently, from the University of Ulm in Germany (Ulm University in Germany) a study may make you more tired, there is no reason.
At present, in vitro fertilization plays an increasingly important role in the treatment of infertility. Children born in vitro fertilization are what people call "test tube babies"". This technology has always been a boon for women unable to conceive in natural ways. But in our country, the success rate of test tube baby is not high, the average is only about 30%.
Recently, a German study by University of Ulm physicist Andrei Sommer led the discovery of human sperm cells, was wrapped in diamond (a diamond Petri dish) the Petri dish survival time and motion activity are higher than in the traditional polystyrene Petri dish, and using near infrared light can also increase the activity of sperm, alone or both joint use can improve the success rate of in vitro fertilization. This is of great significance for the treatment of infertility.
The traditional in vitro fertilization process is to remove the sperm and oocyte respectively, and then put them into the culture medium to make the sperm drill into the oocyte and form the fertilized egg. Then, the fertilized egg is transplanted back into the uterus of the mother. In clinical practice, IVF is usually performed on Petri dishes, and most of the currently used Petri dishes are made from polystyrene.
Like any type of cell, the sperm also produces reactive oxygen species (ROS) that damage the cells during metabolism. Reactive oxygen species, which contain unpaired electrons, are chemically active and interact with cell membranes, proteins and lipids in the cell, resulting in a series of cross-linking reactions, causing damage to cells and even to the body. In the body, reactive oxygen interacts with the surrounding material, and in the process it gets or loses an electron and becomes a stable structure, losing the ability to damage cells.
Polystyrene material can form a colloidal nano thickness water film on its surface, but this water film will hinder the interaction between active oxygen and the surrounding material, so it is not conducive to the neutralization and elimination of reactive oxygen species.
Therefore, in sperm and oocytes in culture dish during that time, the equivalent of their sperm has been in the metabolism of free radicals (oocytes surrounded by free radicals is relatively small, so the ratio of sperm free radical damage tolerance), this will cause great damage to cells, sperm will soon they lost their activity, from fast swimming into an almost stationary state, so the fertilization success rate is relatively low.
Generally speaking, the higher the sperm motility in the sample, the higher the success rate of IVF and the higher the pregnancy rate.
Because the surface of diamond is a smooth water film, it will not hinder the interaction between free radicals and the surrounding substances, and can protect the cells from free radical damage. So Sommer and his colleagues wondered whether sperm culture on surfaces like diamonds would improve the success rate of in vitro fertilization
The researchers then coated the quartz culture dish with an ultra thin diamond layer of less than one micron and cultured the human sperm, and repeated the same experiment on a polystyrene coated Petri dish as a control. The activity of these sperm cells is divided into four levels, from A (fast movement, most likely to fertilization) to D (completely immobile, not fertilized).
After one hour, they found that the number of A grade sperm in the Petri dish wrapped by diamonds was 300% of the A grade sperm in the polystyrene dish. The results were published in the Journal of translational medicine "Annalsof Translational Medicine". Sommer explained that this may be because the reactive oxygen species are unable to aggregate on the surface of the diamond coated dish and are rapidly converted to neutral substances and lose the ability to damage cells.
Previous studies have shown that specific wavelengths of light, such as the wavelength of 670 nm light (at the red end of the visible spectrum), can increase the production of ATP (adenosine triphosphate) in mitochondria of cells, which makes cells more viable. The team also tested the effects of light on sperm motility. After thirty minutes of light exposure, the researchers found that the number of sperm in the experimental group was two times higher than that in the control group.
These findings suggest that the combination of diamond coated dishes and near infrared irradiation will lead to longer sperm survival and higher motility, thereby significantly improving the efficiency of in vitro fertilization.
Of course, the price of the diamond wrapped Petri dish is expensive, and the price of the dish used in the study is about 100 dollars. But Sommer says that the price of this dish is acceptable, given that it costs about 10000 dollars or more for in vitro fertilization.
Ashok Agarwal, a biologist at the Cleveland clinic reproductive medicine center in Ohio, USA, said that this study is not only interesting, but also of great importance to the development of reproductive biology.
But some researchers worry that diamonds can cause damage to sperm and fertilized eggs. Sommer also responded that the study does involve the presence of nanodiamond particles into sperm cells, but this does not happen if the sperm cells are on the surface of inert diamond particles. Nevertheless, the results of this study still have a long way to go in clinical practice.
Perhaps in the future, a healthy babies are from the first order a