Hierarchically Chiral Silver Nanoclusters Mediated Enantioselective Glutathione Depletion and Intracellular Self‐Assembly for Enhanced Anticancer Therapy

Abstract

ABSTRACT Chiral nanomedicine design benefits from understanding enantioselective interactions between hierarchically chiral nanoclusters and tumor biomarkers. In this study, we synthesized a pair of silver nanoclusters with bilevel chirality, designated as D ‐Ag 6 SP 6 and L ‐Ag 6 SP 6 , which were further functionalized with polyethylene glycol (PEG) to enhance their biocompatibility, yielding D ‐Ag 6 SP 6 @PEG and L ‐Ag 6 SP 6 @PEG nanoparticles. Notably, these chiral nanoclusters show enantioselective interactions with glutathione (GSH), as evidenced by their distinct binding constants ( K a ). Specifically, the K a values for L ‐Ag 6 SP 6 are 2.47 × 10 7 M −1 , while those for D ‐Ag 6 SP 6 reach 1.33 × 10 8 M −1 , indicating that the D ‐enantiomer exhibits significantly stronger GSH‐binding affinity. Both D ‐Ag 6 SP 6 @PEG and L ‐Ag 6 SP 6 @PEG deplete intracellular GSH in tumor cells through a ligand‐exchange mechanism, subsequently forming homochiral coordination supramolecular polymers (CSPs) composed of Ag(I)‐GSH complexes. Following adequate aging, these CSPs aggregate into microscale fibers that induce mitochondrial mechanical damage, leading to a significant increase in intracellular reactive oxygen species (ROS) levels, which ultimately induces apoptosis and ferroptosis of tumor cells. Consistently, D ‐Ag 6 SP 6 @PEG demonstrates superior tumor‐killing efficacy in both in vitro and in vivo studies compared with L ‐Ag 6 SP 6 @PEG, attributed to its higher GSH‐binding affinity. This work underscores the significance of chiral design in nanomedicines and provides valuable insights for the development of advanced chiral nanotherapeutics.