Silver and Silver/Sodium Bisphosphonate Salts: Rare Examples of Molecular Solid Solutions and Their Biological Activity as Dual-Action Compounds

Bisphosphonates (BPs) are an important treatment for osteoporosis and bone metastases due to their low toxicity, high thermostability, and the ability to inhibit bone resorption. Notably, BPs like alendronate, which contain a primary amine group, exhibit potent antiresorptive and antiangiogenic properties. Recent studies have focused on enhancing the BP properties by incorporating bioactive metals to increase their therapeutic potential. Here, we describe the synthesis and physicochemical properties of new silver etidronate and alendronate salts. Our research demonstrates the potential of silver bisphosphonate complexes in promoting osteoblast viability while exhibiting significant antimicrobial activity. Moreover, silver/sodium alendronates turned out to be rare examples of molecular solid solutions that allow the adjustment of the concentration of potentially cytotoxic silver cations within the obtained compounds.