Researchers from the German Institute for Integrated Nanoscience and Technology (IIN), IFW, Dresden, have developed 3D printing robots that are driven by bull sperm cells. Robots can load a cervical cancer drug called doxorubicin hydrochloride, which one day can be used to treat human patients. It has been several months since we last heard of the incredible 3D printed sperm being developed by the Dresden Institute for Integrated Nanoscience and Technology. Now the same researchers bring the good news again: they have published a paper on their recent work and said that their latest anti-cancer athlete, again made with bull sperm, shows great promise. Each bio-hybrid sperm micro robot consists of sperm from bulls combined with a plastic 3D printed microstructure covered with an iron-based coating. Metal coatings allow researchers to magnetically "guide" the robot where it is needed, and the four bendable arms on the microstructure release the sperm cells to the target cancer cells. Curiously, although it sounds like sperm are actually very useful for this task because they have the ability to swim in the female reproductive tract. Even better, sperm cells fuse naturally with egg cells and can replicate cancer cell tips, allowing sperm to release important cervical cancer drugs in cancer cells. The drug the researchers are currently using is adriamycin hydrochloride, which can be loaded into the head of every sperm cell. Usefully, the drug has no significant effect on sperm cells, so it can move on even with important medical supplies. These 3D-printed toasters are not yet ready for use in humans, but researchers in Dresden have been successfully tested in laboratory dishes. Finally, they want to experiment with animals and then replace the sperm of bulls with human sperm. However, until significant progress can be made, researchers need to overcome a few barriers: For starters, they want to make the plastic structure of a robot biodegradable, dissolving it immediately after drug delivery, which allows immune and other reactions minimize. Another obstacle involves finding a way to guide multiple sperm cells at a time. Currently, researchers can control one robot at a time, but need to complete multiple robots at once to provide the necessary dose. However, doing so requires better imaging techniques so that doctors can monitor the progress of small robots. At present, the spatial resolution of magnetic resonance and ultrasound imaging systems is about 100 microns, which is not enough to accomplish the task since the sperm head only measures 5x10 microns. The researchers said the researchers' goal is to create a high-resolution system that monitors the entire shampoo in real time. Despite these challenges, researchers in Dresden are very optimistic that their unusual technology will eventually be used for their intended purposes. They even think it can be used to solve other forms of cancer other than cervical cancer, including ovarian cancer and uterine cancer. A similar procedure to artificial insemination was used to inject robotic sperm through the catheter into the female reproductive system. The latest paper by the investigators, the Sperm-Hybrid Miniature Motor for Targeted Drug Delivery, has been published in ACS NanoJournal. Its authors are Xu Haifeng, Mariana Medina Sanchez, Veronica Magdange, Lucas Schwartz, Franzis Kahben Bententer and Oliver G. Schmidt.