H₂O₂ self-supplying degradable epitope imprinted polymers for targeted fluorescence imaging and chemodynamic therapy

Chemodynamic therapy (CDT), the ability to transform H₂O₂ into a highly toxic hydroxyl radical (˙OH) through a Fenton or Fenton like reaction to kill cancer cells, enables selective tumor therapy. However, the effect is seriously limited by the insufficiency of endogenous H₂O₂ in cancer cells. Additionally, the specific recognition of epitope imprinting plays an important role in targeting cancer cell markers. In this work, we prepared H₂O₂ self-supplying degradable epitope molecularly imprinted polymers (MIP) for effective CDT, employing fluorescent calcium peroxide (FCaO₂) as an imaging probe and a source of H₂O₂, the exposed peptide in the CD47 extracellular region as the template, copper acrylate as one of the functional monomers and N,N'-bisacrylylcystamine (BAC) as a cross-linker. MIP with recognition sites can specifically target CD47-positive cancer cells to achieve fluorescence imaging. Under the reduction of glutathione (GSH), the MIP were degraded and the exposed FCaO₂ reacted with water to continuously produce H₂O₂ in the slightly acidic environment in cancer cells. The self-supplied H₂O₂ produced ˙OH through a Fenton like catalytic reaction mediated by copper ions in the MIP framework, inducing cancer cell apoptosis. Therefore, the MIP nano-platform, which was capable of specific recognition of the cancer cell marker, H₂O₂ self-supply and controlled treatment, was successfully used for targeted CDT.