NSF East Asia and Pacific Summer Institute (EAPSI) for FY 2013 in China

Smith Douglas C, Houghton MI

Investigators

Abstract

This action funds Douglas Smith of Michigan Technological University to conduct a research project in the Mathematical and Physical Sciences area during the summer of 2013 at Beijing Institute of Technology in Beijing, China. The project title is "Nanoparticle-based Fluorescent Sensors for Measurement of Acidic Intracellular pH in Living Cells." The host scientist is Dr. Si-ping Pang. Intracellular pH plays many critical roles in cell, enzyme and tissue activities, including proliferation and apoptosis, ion transport, endocytosis, and muscle contraction. Cellular dysfunction is often associated with abnormal pH values in organelles (mitochondria, lysosomes, etc.). Monitoring pH changes inside living cells is also important for studying cellular internalization pathways, such as phagocytosis, endocytosis, and receptor ligand internalization. The Fellow synthesized a series of new fluorescent sensors in his home lab (Michigan Tech. Univ.). Several features of the sensors (absence of cytotoxicity, high cell permeability, and long-lived intracellular fluorescence) make the pH sensors superior candidates for examining intracellular pH alterations in intact cells. Other commercially available pH sensors do not exhibit these features. Accordingly, the sensors offer novel experimental opportunities for live-imaging in intact cells over multiple time points (hours), and thus add a new tool in understanding intracellular alterations in normal and cancerous cell growth. The easily accessible terminal alkyne/ azido "clickable" function groups of these sensors offer the possibility of rapidly constructing sensor molecule libraries using "click" chemistry. This project exploits this approach to prepare multiple nanoparticle-based fluorescent sensors. Broader impacts of an EAPSI fellowship include providing the Fellow a first-hand research experience outside the U.S.; an introduction to the science, science policy, and scientific infrastructure of the respective location; and an orientation to the society, culture and language. These activities meet the NSF goal to educate for international collaborations early in the career of its scientists, engineers, and educators, thus ensuring a globally aware U.S. scientific workforce.