Copper coated β-tricalcium phosphate nanoparticles with enhanced antimicrobial and selective anticancer activity: structural, optical, and biological insights.

Bacterial infections and cancer remain major challenges in biomedical applications, highlighting the need for multifunctional nanomaterials with enhanced antibacterial and anticancer properties. This study aimed to develop copper-coated β-tricalcium phosphate (Cu@β-TCP nanoparticles) nanoparticles to address these challenges. XRD confirmed retention of the rhombohedral β-TCP structure with reduced crystallite size after copper coating (18 ± 1.5 nm vs. 25 ± 2 nm). SEM, TEM, and DLS revealed smaller, spherical, and well-dispersed Cu@β-TCP nanoparticles. FTIR and XPS indicated preserved phosphate groups and successful copper deposition. Cu@β-TCP nanoparticles exhibited superior antibacterial and antifungal activity, lower MIC values, and faster bacterial killing compared to β-TCP. Cytotoxicity studies against MG-63 osteosarcoma cells showed IC₅₀ values for Cu@β-TCP nanoparticles of 119.2 µg/mL (24 h), 109.8 µg/mL (48 h), and 100.8 µg/mL (72 h), compared to 127.3 µg/mL, 120.6 µg/mL, and 115.6 µg/mL for β-TCP, while maintaining high fibroblast viability (> 81%). These results demonstrate that copper coating enhances the physicochemical properties, selective cytotoxicity, and antimicrobial performance of β-TCP, making Cu@β-TCP nanoparticles a promising candidate for biomedical applications.