Israeli-founded Bionaut Labs (see here previously) has safety-tested its micro robot containing a magnet, that can travel via spinal fluid, directly to the brain, to deliver therapy or perform surgery. It can also navigate to any part of the body. Bionaut plans to begin human trials in late 2024.

https://www.timesofisrael.com/spotlight/400m-apple-face-id-inventors-create-tiny-robot-to-treat-brain-disease/

https://www.ourcrowd.com/companies/bionaut-labs

https://www.youtube.com/watch?v=8PrPbevTDqE