SGER: Surface Chemistry in metal oxide nanoparticle cytotoxicity

The University Of Central Florida Board Of Trustees, Orlando FL

Investigators

Abstract

Sudipta Seal University Central Florida CBET-0711239 SGER: Surface Chemistry in Metal Oxide Nanoparticle Cytoxicity The rapid expansion of nanotechnology has resulted in a vast array of nanoparticles (NPs) that vary in size, charge, chemistry and solubility. Inorganic nanoparticles, in particular, are shown to be effective in scavenging oxygen free radicals which can cause many clinical diseases such as cellular dysfunction in living organisms. Some of the NPs are shown to be toxic and can generate harmful free radicals. Our research has shown the beneficial therapeutic properties of rare earth NPs which are considered to be non-toxic. The unique property of ceria NPs in radical scavenging is due to their ability to undergo reversible redox reaction between the +3 and +4 states, thereby scavenging the free radicals into harmless by-products, mimicking the properties of natural enzyme. Further we have shown that doping can increase number of oxygen vacancies which is likely to improve the free radical scavenging properties. Recently we have reported the effectiveness of micromolar concentrations of ceria NPs (Nature Nanotechnology, 2006) in preventing the photoreceptor cell damage due to reactive oxygen species in the primary cell cultures of rat retina. But still a comprehensive understanding on NP surface properties with biological activity is required for optimum therapeutic properties. Specific objectives: In comparison to other metal oxides and anti-oxidants, rare earth metal oxide NPs exhibit superior free radical scavenging properties and are non toxic. The co-existence of both Ce3+ and Ce4+ in the engineered NPs plays a critical role in its antioxidant behavior and enables it to be an active free radical scavenger. It is also not known how NP size, surface charges, agglomeration, dopant nature and concentration govern the activity of the NPs in vivo. Present project will address these important issues and the main objectives are: (i) to synthesis of NPs and characterizing size and surface properties, (ii) to study the influence of zeta potential on the cellular uptake, (iii) to determine the cytotoxicity of NPs in skin and lung culture models, (iv) to assess the oxidative stress induced by NPs using cell cultures.