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

该行动资助密歇根理工大学的道格拉斯史密斯于2013年夏天在中国北京的北京理工大学进行数学和物理科学领域的研究项目。 该项目的标题是“用于测量活细胞中酸性细胞内pH值的基于纳米颗粒的荧光传感器”。“主持科学家彭思平博士指出，细胞内pH值在细胞、酶及组织的活动中扮演重要角色，包括细胞增殖及凋亡、离子转运、内吞作用及肌肉收缩。细胞功能障碍通常与细胞器（线粒体、溶酶体等）中的异常pH值相关。监测活细胞内的pH变化对于研究细胞内化途径也很重要，例如吞噬作用、内吞作用和受体配体内化。 该研究员在他的家庭实验室（密歇根理工大学）合成了一系列新的荧光传感器。Univ.）。传感器的几个特征（不存在细胞毒性、高细胞渗透性和长寿命的细胞内荧光）使得pH传感器成为检查完整细胞中细胞内pH改变的上级候选者。其他市售pH传感器不具有这些特征。因此，传感器为在多个时间点（小时）内对完整细胞进行实时成像提供了新的实验机会，从而为理解正常细胞和癌细胞生长中的细胞内变化提供了新的工具。 这些传感器的末端炔/叠氮基“可点击”官能团提供了使用“点击”化学快速构建传感器分子库的可能性。 该项目利用这种方法制备多个基于纳米颗粒的荧光传感器。 EAPSI奖学金的更广泛的影响包括为研究员提供美国以外的第一手研究经验;介绍各自所在地的科学，科学政策和科学基础设施;以及社会，文化和语言的方向。 这些活动符合NSF的目标，即在科学家，工程师和教育工作者的职业生涯早期进行国际合作教育，从而确保具有全球意识的美国科学工作者。

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.