University of South Carolina, Department of Chemistry and Biochemistry
“INTERFACIAL CHEMISTRY OF SEMICONDUCTOR NANOCRYSTALS”
Colloidal semiconductor nanocrystals – a type of quantum dot (QD) – are well-known as bright, highly photostable inorganic fluorophores that can be well-suited to imaging applications in biology. Additionally, the delocalized electronic states present in nanoscale semiconductors should offer distinctive ways to interact with and report on the biological environment. Such applications require good control of the interfacial chemistry of inorganic nanoparticles: in particular, to guide the formation of core/shell heterostructures to optimize brightness, and to introduce a surface coating that can enable the particles to function properly in the biological environment while limiting hydrodynamic size and avoiding quenching of the QD excited state. Significant progress has been made in identifying specific examples that comprise these features, especially for the case of metal chalcogenide semiconductors, but there remains only a limited understanding of the reaction mechanisms and thermodynamics associated with the elaboration of the surfaces of such particles with inorganic and organic layers. I will describe...Read More
East Carolina University, Department of Pharmacology & Toxicology, Brody School of Medicine
“UNDERSTANDING MAST CELL ACTIVATION IN THE DEVELOPMENT OF SAFE NANOTECHNOLOGIES”
Concern about the use of engineered nanomaterials (ENMs) has increased significantly in recent years due to potentially hazardous impacts on human health. Mast cells are critical for innate and adaptive immune responses, often modulating allergic and pathogenic conditions. Mast cells act in response to environmental danger signals such as IL-33 and the IL-1 like receptor ST2. We have examined the involvement of mast cells and the IL-33/ST2 axis in adverse responses to ENMs. Mice with normal mast cell populations exhibit significant ENM directed systemic and pulmonary inflammation, fibrosis, altered lung function and exacerbated cardiac IR injury. In contrast, these toxicological effects of ENMs were not observed in mice deficient in mast cells or mice with mast cells unable to respond to IL-33. Lastly, we have established that certain ENMs are capable of inducing mast cell activation in vitro. Our findings establish for the first time that mast cells orchestrate adverse immune effects to ENMs giving insight into a previously unknown mechanism of toxicity...Read More
Sharonda recently defended her Ph.D. dissertation, entitiled: "Electric field dependent spectroscopy of single nanocrystal systems" in front of a packed audience. She completed the work under the supervision of Dr. Patrick Moyer (Physics and Optical Science) and Dr. Marcus Jones (Chemistry) and will soon be starting a postdoctoral position with Dr. Gloria Elliot (Mechanical Engineering and Engineering Science) at UNC Charlotte.