EAGER: Enhancing the Radical Scavenging Activity of Oxide Nanoparticles Beyond the Current Limits - an Unconventional Solution through Multidisciplinary Science

University Of Kentucky Research Foundation, Lexington KY

Investigators

Abstract

1708057 EAGER: Enhancing the Radical Scavenging Activity of Oxide Nanoparticles Beyond the Current Limits - an Unconventional Solution through Multidisciplinary Science Reactive oxygen species are formed as a natural byproduct of normal metabolism in biological systems. Their levels can increase dramatically during times of environmental stress such as sun's ultraviolet light, ionizing radiation, exposure to toxic chemicals, atmospheric pollutants, and inflammation. The imbalance between the production of reactive oxygen species and their removal by antioxidants results in a net accumulation of these species in the body, leading to the destruction of the cells and can cause a range of disorders such as cancer, Parkinson's disease, Alzheimer's disease, heart failure, stroke, autism, vitiligo, and depression. Engineered oxide nanoparticles have been shown to possess antioxidant activity and the ability to effectively regulate and scavenge a variety of reactive oxygen species. Despite many successes in the field, new breakthroughs are still needed to develop safer and more effective therapeutic nanoparticles. This research project seeks to establish a new approach toward the design and engineering of nanoparticles with high efficacy for trapping the reactive oxygen species in biological systems. The outcome of this project will allow researchers to further expand the family of nanoparticles used for the prevention and treatment of various types of diseases, and will ultimately impact society's health status and well-being. Besides the immediate impact of this research on the use of nanoparticles for therapeutic applications, the proposed scientific concept has the potential to lead to the discovery of highly responsive and selective nanoparticles for emerging applications such as real time selective biosensors, engineered plant functions for solar energy harvesting, and non-degradable polymeric membranes for low-emission vehicles. Cerium oxide (ceria) nanoparticles have demonstrated the potential to actively scavenge a variety of reactive oxygen species in cell and animal models. The capacity of ceria nanoparticles to scavenge free radicals is strongly related to the exposed particle surfaces and considerably constrained by the limited number of oxygen vacancies on the surface. While the relatively immobile lattice vacancies in the core of particles do not contribute to the observed scavenging capacity of ceria nanoparticles, it may be possible to access these vacancies to regenerate the consumed oxygen vacancies on the surface to enhance the scavenging activity. In this Early Grant for Exploratory Research (EAGER) project, an unconventional approach, based on the principles of oxygen vacancy migration in the field of solid state ionics, will be applied to explore fundamental relationships between lattice ion mobility and the surface scavenging activity of nanoparticles. The specific objective of the proposed research is to explore the scavenging properties of barium cerate nanoparticles in comparison with ceria nanoparticles in order to compare two compounds with similar transition metal cations (cerium), but with significantly different oxygen-ion mobilities. Utilizing lattice vacancies and continuous regeneration of surface oxygen vacancies to enhance the scavenging activity of nanoparticles is an entirely new concept to advance the field in novel and unexplored ways. A multidisciplinary team will synthesize and characterize oxide nanoparticles, and will evaluate the scavenging activity and redox-induced surface changes of the nanoparticles using spectroscopic and electrochemical techniques.