Jan Hormann demonstrates the new development and optimization of artificial nucleases using cyclen-based copper complexes as an example, with a particular focus on the synthetic work and biochemical evaluation of the nucleases. This is an important research contribution, as the development of new cancer drugs is becoming increasingly significant due to the rising resistance to established medications. Current research is particularly focused on artificial metallo-nucleases, which can cleave DNA into small fragments, thereby disrupting vital cellular processes and ultimately leading to cell death.