Biomimic Binding Affinity Gradients Triggered GSH-Response of Core-Shell Nanoparticles for Cascade Chemo/Chemodynamic Therapy.

In eukaryotes and prokaryotes, some copper transportations driven by gradient copper-binding affinities exhibit typical glutathione (GSH)-responsive features. Inspired by these delicate endogenous processes, a biomimic copper-ion mediated GSH-responsive nanomedicine is designed based on the gradient copper-binding strengths between polydopamine (PDA) species and GSH. The nanomedicine is constructed as core-shell nanoparticles with copper-polydopamine (Cu-PDA) coordinated shell and micellar core encapsulating chemotherapeutic drug of β-lapachone (β-lapa). In tumor cells, the excess intracellular GSH will reduce and extract the Cu(II) from the Cu-PDA network, triggered by the binding affinity gradients between Cu-PDA and Cu-GSH, resulting in the breaking of the shell and the releasing of β-lapa and Fenton agent copper. The additional Fenton reaction of copper ions induces excess oxidative damage of tumor cells assisted by the abundant H2 O2 amplified by β-lapa, achieving cascade anticancer effects combining chemodynamic therapy with chemotherapy. This multilevel anticancer system exhibits an efficient tumor inhibitory rate and a negligible systematic toxicity for normal organs in vivo, presenting a new bioinspired GSH-responsive strategie to develop stimuli-responsive structures.