Selectively activated plasma protein, DNA and cancer-cells by CB-Cu/Ag NPs

Here, we reported the sustainable synthesis of metal nanoparticles (M = Cu and Ag) via eco-friendly, co-precipitation process using an aqueous extract of cinchona bark (CB) loaded with 0.005M CuCl₂.2H₂O and 0.01M AgNO₃. Synthesize nanoparticles were characterized by different spectroscopic techniques. Their small particle sizes and distinct morphologies contribute to enhanced cellular uptake and improved interaction with biological targets, making them promising candidates for cancer treatment. The main objectives of this work are that the resulting nanoparticles were designed for passive targeted drug delivery through plasma protein (BSA/HSA) and CT-DNA binding. CB-CuONPs exhibited protein binding constants of 0.225 × 10¹¹M⁻¹ for BSA and 0.266 × 10¹¹M⁻¹ for HSA. Whereas CB-AgNPs showed higher affinity at 0.541 × 10¹¹M⁻¹ for BSA and 0.513 × 10¹¹M⁻¹ for HSA, and strongly interacted with CT-DNA (3.0669 × 10¹¹M⁻¹). Cytotoxicity studies revealed that CB-CuONPs showed potent cytotoxic activity, with IC₅₀ concentrations of 65.8 μg for KB3 oral cancer KB3 cell line and 26.2 μg for AGS Colon cancer cell line, compared to CB-AgNPs (70.6 μg for KB3 and 54.6 μg for AGS cell lines). Combined cytotoxicity and biocompatibility findings suggest that CB-CuONPs may be more promising anticancer candidates than CB-AgNPs when used with proper dosage control. Additionally, molecular docking confirmed strong binding interactions of cinchona phytochemicals with BSA and CT-DNA, supporting their potential for passive targeted cancer therapy with minimal side effects toward eukaryotic cells.