Researchers develop safe and accurate 3D imaging methods to improve IVF treatment

Researchers at Tel Aviv University (TAU) have developed a safe and accurate 3D imaging technique for identifying fast-moving sperm cells.

The research was published that research Scientific progress On April 10th, Professor Natan Shaked of the Department of Biomedical Engineering in the Faculty of Engineering of TAU and TAU’s PhD student Gili Dardikman-Yoffe took the lead.

New technology may allow doctors to choose the highest quality sperm for injection into eggs during IVF treatment, increasing the likelihood that a woman will become pregnant and have a healthy baby.

The IVF procedure was invented to help with fertility problems. The most common type of IVF today is intracytoplasmic sperm injection (ICSI). This includes the selection of sperm by clinical embryologists and injection into female eggs. To that end, efforts are being made to select sperm cells that are most likely to produce healthy embryos. “

Nathan Shake, TAU, Faculty of Engineering, Department of Biomedical Engineering, Professor

In the natural fertilization of the female body, the fastest sperm that reach the ova are believed to have high quality genetic material. The progressive movement allows this “best” sperm to overcome a true obstacle course in the female reproductive system.

“But this” natural selection “is not available to embryologists who select sperm and inject them into their eggs,” says Professor Sheikh. “Sperm cells are not only fast moving, they are also almost transparent under normal light microscopy, and staining of cells is not allowed in human in vitro fertilization.

“This is also prohibited because existing imaging techniques that can determine the quality of sperm genetic material can cause embryo damage. In the absence of more accurate standards, sperm cells are primarily exogenous. It is selected according to its characteristics and motility when swimming underwater, a dish that is very different from the natural environment of the female body.

“Our research provides as much information as possible about individual sperm cells, does not require cell staining to enhance contrast, and may enable optimal sperm selection, a whole new Tried to develop a type of imaging technology. Fertilization treatment. “

The researchers chose optical computed tomography (CT) technology for the unique task of imaging sperm cells.

“In a standard medical CT scan, the device rotates around the subject, sending X-rays that produce multiple projections, and ultimately creating a 3D image of the body,” says Shaked. .. “In the case of sperm, instead of rotating the device around this little target, we relied on the natural features of the sperm itself. The head is constantly rotating during forward movement.

“We used weak light that did not damage the cells (rather than X-rays.) We recorded a hologram of sperm cells during ultra-fast motion and identified various internal components according to their refractive index. A highly dynamic 3D is created that maps its contents without the use of cell staining. “

Using this technique, researchers acquired clear and accurate CT images of sperm in 4D with very high resolution. The 3D dimension of the space was acquired accurately with a resolution of less than 0.5 micron (1 micron is equivalent to one millionth of a meter). Second sub-millisecond time (motion) dimension.

“Our new development provides a comprehensive solution to many known problems in sperm imaging,” says Sheik. “We were able to create high-resolution images of the sperm head while moving at high speeds without the need for staining, which could harm the embryo. Significantly improved sperm cell selection, potentially pregnant and the birth of a healthy baby.

“To assist in diagnosing male fertility problems, we are using new technologies to relate 3D movement, sperm structure and content, and the ability to fertilize an egg to produce a viable pregnancy. We will shed some light on it, ”concludes Professor Sheikh. “We believe such imaging capabilities will contribute to other medical applications, such as the development of efficient biomimetic microrobots for delivering drugs into the body.”