Structure and biomolecular binding behaviour of a polymeric Cu(II) complex with notable anticancer activity

Copper-based complexes have attracted significant interest in anticancer studies because of their diverse coordination behaviour, redox properties, and capacity to produce reactive oxygen species that cause programmed cell death in tumour cells. In quest of more effective targeted therapies, a polymeric copper(II) complex, expressed as [(Cu(PCA)₂)·2H₂O]ₙ, was synthesized in this study using pyridine-2-carboxylic acid (PCA) as the coordinating ligand. Comprehensive investigations were conducted to evaluate its structural characteristics, DNA and bovine serum albumin (BSA) binding interactions, and its anti-breast cancer potential against the MDA-MB-231 breast cancer cell line. Single-crystal X-ray diffraction analysis revealed a polymeric framework in which copper centers are bridged by the carboxylate groups of PCA ligands, forming one-dimensional chains. DNA binding studies indicated an intercalative binding mode, with thermodynamic parameters derived at multiple temperatures suggesting that hydrophobic interactions predominantly govern this association. The complex also demonstrated a static quenching mechanism during its interaction with BSA. Biological evaluations demonstrated that the complex significantly suppressed cell proliferation and migration, as confirmed by colony formation and wound healing assays. Moreover, the complex exhibited remarkable biocompatibility and negligible toxicity toward normal cells, as evidenced by the absence of red blood cell lysis in the hemolytic assay and cytotoxicity assay. These findings highlight its promise as a safe and biocompatible candidate for potential intraperitoneal and oral delivery in breast cancer therapy. • A 1D polymeric Cu(II) complex was synthesized and characterized by SCXRD. • The complex intercalates with DNA and binds BSA via static quenching. • Shows strong anticancer activity against MDA-MB-231 breast cancer cells. • Exhibits excellent biocompatibility with negligible hemolysis in vitro.