Associate Professor Jin Xie | Department of Chemistry, University of Georgia

Abstract: A wide range of inorganic nanoparticles have been made and tested for bio-applications. Yet, nanoparticles made of alkali halides have been rarely studied. The underlying assumption is that electrolyte nanoparticles will quickly dissolve in water and behave similarly as their constituent salts. Our recent studies challenge this preconception. For instance, we found that NaCl nanoparticles (SCNPs) but not salts are toxic to cancer cells. This is because SCNPs enter cells through endocytosis, bypassing cell regulations on ion transport. When dissolved inside cancer cells, SCNPs break the osmotic balance, causing cancer cell death. Another example is CsI(Na) nanoparticles. CsI(Na) nanoparticles produce ~410 nm luminescence under X-ray radiation. The X-ray luminescence can in turn activate a photosensitizer such as protoporphyrin IX (PpIX), a phenomenon known as X-ray induced photodynamic therapy (X-PDT). PpIX accumulates in the mitochondria of cancer cells that have been treated with 5-aminolevulinic acid (5-ALA). Our studies show that combining CsI(Na) nanoparticles and 5-ALA can sensitize cancer cells to radiation therapy (RT) due to synergy between mitochondria-targeted X-PDT and DNA-targeted RT. For both SCNPs or CsI(Na) nanoparticles, the nanomaterials are dissolved to alkali metal ions and halides, which are safely excreted after treatment. Overall, alkali metal nanoparticles represent a novel type of nanomaterials that hold potential in cancer therapy and other bio-applications.

Bio: Jin Xie is currently an associate professor in the Department of Chemistry, University of Georgia (UGA). Xie also holds an adjunct associate professor position at the UGA School of Chemical, Materials, and Biomedical Engineering. Xie obtained a Ph.D. in Chemistry from Brown University in 2008. He worked as a postdoc in the Molecular Imaging Program at Stanford University (2008-2009). He then moved to the National Institute of Biomedical Imaging and Bioengineering (NIBIB) as a research fellow. In 2011, he joined the faculty of UGA Chemistry as an assistant professor. He was promoted to associate professor with tenure in 2017. His research interests include nanoparticle-based drug delivery, radiotherapy, and photodynamic therapy. He serves as an associate editor for the Journal of Nanobiotechnology. He has received a number of awards, including the NSF Career Award, NIH Pathway to Independence Award, Young Innovator Award in Nanobiotechnology by Nano Research, and the NIBIB Outstanding Researcher Award. He has published more than 120 peer-reviewed articles in the fields of nanomedicine, drug delivery, and imaging.

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