A cerium oxide nanoparticles (nanoceria) has a wide range of applications in different fields, especially biomedical division. As a matter of concern, it has a major impact on the human health and environment. The aim of this review is to address the different ways of synthesis of nanoceria using chemical and green synthesis methods and characterization and the applications of nanoceria for antioxidant, anticancer, antibacterial activities and toxicological studies including the most recent studies carried out in vivo and in vitro to study the problems. We have exclusively discussed on the toxicology of nanoceria exposed to the general public along with recent advances in the studies of antimicrobial, toxicity and anti-oxidant activity.

Gold nanoparticles have many applications in biomedical field. Improving delivery of anticancer agents to tumors using nanoparticles is one of the most promising research arenas in the field of nanotechnology. Eco-friendly gold nanoparticles synthesis was studied using marine bacteria Enterococcus sp. The nanoparticle synthesis started at 2 h of incubation time was identified by the formation of ruby red in the reaction mixture and SPR band centered at 545 nm. XRD shows that the strong four intense peaks indicate crystalline nature of nanoparticles. Morphology of nanoparticles analyzed by TEM shows that they are mostly spherical in shape with size ranging from 6 to 13 nm. EDX supports the presence of gold in the synthesized nanoparticles. FTIR reveals the active functional groups in the culture supernatant interaction with gold nanoparticles. As a result synthesized stable gold nanoparticles show more significant anticancer activity against HepG2 and A549 cells at 100 μg concentration of nanoparticles. This synthesis approach is simple, large scaled up a new door for development of targeted anticancer activity using gold nanoparticles and is novel in biomedical applications.