Green synthesis of CuO nanoparticles using mangrove leaves for targeted delivery of platinum (II) therapeutics.

Copper oxide nanoparticles (CuO NPs) synthesized via green chemistry using Avicennia marina mangrove leaf extract represent an environmentally sustainable approach to generating biocompatible nanomaterials for pharmaceutical applications. This study utilized the phytochemical-rich extract as both a reducing and capping agent to produce quasi-spherical monoclinic CuO NPs with a diameter range of 35-87 nm. The resulting nanoparticles possessed a specific surface area of 4.5 m² g⁻¹ with a mesoporous structure (pore volume of 0.018 cm³ g⁻¹), making them ideal candidates for drug loading applications. The CuO NPs were subsequently evaluated as nanocarriers for two clinically relevant platinum (II) chemotherapeutics: cisplatin and oxaliplatin. Characterization via Fourier-transform infrared spectroscopy confirmed successful coordination of platinum drug ligands to surface Cu/O sites, while Brunauer-Emmett-Teller analysis demonstrated a substantial decrease in surface area upon drug loading, indicating effective pore occupancy. Cisplatin demonstrated an entrapment efficiency of 28% with a loading capacity of 56 mg/g, while oxaliplatin exhibited comparable loading performance. The in vitro release profiles of cisplatin and oxaliplatin from mangrove-derived green CuO NPs show sustained release, with cisplatin reaching 70% cumulative release within 20 h and oxaliplatin approaching 80% in the same period. The release kinetics follow first-order behavior for cisplatin and Higuchi model for oxaliplatin, indicating that release is predominantly governed by diffusion from the mesoporous CuO matrix. These findings establish mangrove-derived CuO nanoparticles as a promising carrier for sustainable platinum-based drug delivery, offering an environmentally friendly approach and enhanced therapeutic potential while eliminating the need for toxic precursors and energy-intensive conventional synthesis methods.