Copper and metformin double-doped polydopamine nanoparticles for tumor photothermal therapy

The anti-tumor potentials of copper and metformin have been wildly studied. Excessive intracellular copper could lead cancer cells to cuproptosis, while metformin could activate adenosine monophosphate-activated protein kinase (AMPK) to decrease ATP and generate reactive oxygen species (ROS). This study integrated copper and metformin ably to form a polydopamine nanoparticle (CMP NPs) through coordination bonds. CMP NPs showed a high photothermal efficiency and anti-tumor efficacy both in vitro and in vivo experiments. This effective photothermal therapy (PTT) not only inhibited the growth of primary tumors but also generated an in-situ tumor vaccine-like function by immunogenic cell death to restrain the regrowth of the secondary tumors, showing a promising PTT for malignant solid tumors.