The research team of the Catalan Institute of Bioengineering in Spain has recorded the entire process of human embryo implantation in real time for the first time through 3D dynamic imaging technology. This breakthrough achievement provides an important basis for a deeper understanding of implantation mechanisms and improving the success rate of assisted reproduction. Uterine implantation failure is one of the main causes of infertility, accounting for 60% of natural miscarriage cases. The latest research has found that during implantation, human embryos slowly advance deep into the uterus like "drilling", not only releasing enzymes to break down surrounding tissues, but also exerting force to break through collagen rich fiber structures. This collagen is as tough as a rope and also exists in tendons and cartilage. The embryo opens the way while starting to construct tissues connected to the mother's blood vessels, laying the foundation for obtaining nutrients for itself. The team observed that the embryos were not passively embedded, but were actively constructed. It pulls the uterine stroma, causing it to move, reorganize, and respond to mechanical signals from the outside. Efficient implantation is accompanied by optimal displacement of the matrix, indicating that mechanical force is indispensable in this process. They speculate that uterine contractions in the body may affect the smooth progress of this process. To conduct research, the team developed a platform. This platform is an artificial matrix composed of collagen and various essential proteins for development, which allows embryos to implant under controlled conditions outside the uterus, enabling real-time fluorescence imaging and analyzing the mechanical interactions between embryos and the surrounding environment. The team conducted experiments using both human and mouse embryos to compare the two implantation processes. It was found that when mouse embryos come into contact with the uterus, they first grasp the surface, and then the uterus folds and wraps around the embryo like a blanket, forming a "uterine crypt". The strategy of human embryos, on the other hand, is completely different. They will "drill through" inward and completely embed into the uterine tissue, growing radially from the inside out. People's deep understanding of the process of embryo implantation may have a significant impact on fertility rates, embryo quality, and the time required for conception through assisted reproduction. (New Society)