Insights into the Dual Anticancer and Antibacterial Activities of Composites Based on Silver Camphorimine Complexes

Hydroxyapatite (HAp) is a widely used biocompatible material in orthopedic composite preparations. However, HAp composites that exhibit both anticancer and antibacterial activities through bioactive coordination complexes are relatively rare. To explore orthopedic applications, we blended several silver camphorimine compounds with HAp to create [Ag(I)] composites. All compounds [Ag(NO₃)(L)_n] (n = 1,2) based on camphorimine (L^A), camphor sulfonimine (L^B) or imine bi-camphor (L^C) ligands demonstrated significant cytotoxic activity (IC₅₀ = 0.30-2.6 μg_Ag/mL) against osteosarcoma cancer cells (HOS). Based on their structural and electronic characteristics, four complexes (1-4) were selected for antibacterial evaluation against Escherichia coli, Burkholderia contaminans, Pseudomonas aeruginosa, and Staphylococcus aureus. All complexes (1-4) revealed combined anticancer and antibacterial activities; therefore, they were used to prepare [Ag(I)]:HAp composites of 50:50% and 20:80% weight compositions and the activities of the composites were assessed. Results showed that they retain the dual anticancer and antibacterial characteristics of their precursor complexes. To replicate the clinical context of bone-filling applications, hand-pressed surfaces (pellets) were prepared. It is worth highlighting that no agglutination agent was necessary for the pellet's consistency. The biological properties of the so-prepared pellets were assessed, and the HOS cells and bacteria spreading on the pellet's surface were analyzed by SEM. Notably, composite 4B, derived from the bicamphor (L^C) complex [Ag(NO₃)(OC₁₀H₁₄N(C₆H₄)₂NC₁₀H₁₄O)], exhibited significant anticancer activity against HOS cells and antibacterial activity against P. aeruginosa, fostering potential clinical applications on post-surgical OS treatment.