Local Electrochemical Generation of Reactive Oxygen Species for Targeting Cancer Cells

Cancer is one of the leading death causes worldwide. Therefore the de,velopment and advancement of anti-tumor treatments, which can be applied supplementary to surgery and also minimize the harm to the patient, are of importance.<br/>One approach to achieve this goal is the application of reactive oxygen species (ROS) -mediated cell death. At elevated concentrations ROS can induce damage to cells due to oxidative stress and can further lead to apoptosis. Due to the high reactivity of especially hydroxyl radicals, the molecules' lifetime is rather short resulting in a very small transport distance and consequently to a confined range in the body. ROS-mediated therapies like photodynamic therapy or Fenton nano particle-based systems are already widely investigated. However, they might be either limited by the penetration depth of the light, lack efficiency due to constrained availability of reactants or suffer from particle aggregation.<br/>To address these problems, we introduce implantable electrochemical devices for direct current anti-tumor treatment with local ROS generation. On a metal cathode H₂O₂is produced via 2e^-oxygen reduction reaction which ensures sufficient availability of peroxide with simultaneous oxygen deprivation. Concurrently, a metal serves as a sacrificial counter electrode and dissolves due to oxidation. The released metal ions and H₂O₂ react in a Fenton-like way, leading to formation of hydroxyl radicals.<br/>Here, we present a novel platform for local ROS delivery based on the electrogeneration of H₂O₂ and metal dissolution followed by radical formation and show proof-of-concept on a A375 cell line.