**10. Silver nanoparticles for drug-delivery systems**

Metallic nanoparticles had emerge as probable antimicrobial agents due to their ultra-small size, high surface to volume ratio, novel physiochemical properties rooted from interaction with microbes including cellular uptake and aggregation leading to toxicity and death of the microbe [39]. Ligand dependent silver release with drug may offer potent synergistic antimicrobial activities not only for drug but also for AgNPs due to their short carbon chain and weak binding atom of oxygen. Therefore, the optimization of the surface ligands such as coordination atoms, carbon chain lengths and terminal groups is very important to prepare nanoparticles for commercial applications against infectious diseases [40]. Research evidences shows that modification of silver nanoparticles could be exploited for drug delivery and are used to modulate the toxic actions of drugs. It also accompanies that as the concentration increases, non-significant reduction in the cytotoxic actions for the silver nanoparticle conjugates were relative to the cytotoxicity of the cells.
