A novel bone cement impregnated with silver-tiopronin nanoparticles: its antimicrobial, cytotoxic, and mechanical properties

Post-operatory infections in orthopedic surgeries pose a significant risk. The common approach of using antibiotics, both parenterally or embedded in bone cement (when this is employed during surgery) faces the challenge of the rising population of pathogens exhibiting resistance properties against one or more of these compounds; therefore, novel approaches need to be developed. Silver nanoparticles appear to be an exciting prospect because of their antimicrobial activity and safety at the levels used in medical applications. In this paper, a novel type of silver nanoparticles capped with tiopronin is presented. Two ratios of reagents during synthesis were tested and the effect on the nanoparticles investigated through TEM, TGA, and UV-Vis spectroscopy. Once encapsulated in bone cement, only the nanoparticles with the highest amount of inorganic fraction conferred antimicrobial activity against methicillin resistant Staphylococcus aureus (MRSA) at concentrations as low as 0.1% w/w. No other characteristics of the bone cement, such as cytotoxicity or mechanical properties, were affected by the presence of the nanoparticles. Our work presents a new type of silver nanoparticles and demonstrates that they can be embedded in bone cement to prevent infections once the synthetic conditions are tailored for such applications.