Biomimetic Hierarchical Construction of Anti-Tumor Polyoxopalladates for Cancer Therapy

Inspired by the construction scheme of biomacromolecules, a hierarchical assembly based on the lacunary polyoxopalladate (POP) of [SrPd₁₂O₆(OH)₃(PhAsO₃)₆(OAc)₃]^4- (SrPd₁₂) has been achieved. As a structurally programmable molecular building block, SrPd₁₂ is used to evolve from monomer via dimer to supramolecular aggregates in a controlled manner. In such process, the open-shell-type monomers are covalently integrated into bowl- or cage-like dimers via a direct or indirect splicing strategy. Upon that, hydrogen bond and hydrophobic effects are further hired to fabricate supramolecular aggregates of varied host-guest archetypes, thereby completing a hierarchical construction. In consideration of the combined advantages of noble metals and polyoxometalates in cancer treatment, both in vitro and in vivo anti-tumor assays of these SrPd₁₂-derived POPs were studied in detail. A structure-dependent anti-tumor activitywas observed, originating from an imbalance of damage and repair of DNA as anti-tumor mechanism.