Fundamental Studies of the Effects of Auger Electrons Emitted in Different Subcellular Compartments of Human Cells

俄歇电子(AEs)是一种能量很低的电子(我们将设计新型的“纳米穿梭”运载工具，将111In、67Ga或99mTc传送到选定的亚细胞隔室。纳米航天飞机将由以细胞表面v3整合素为靶点的多肽修饰的金纳米颗粒(AuNPs)和将内化的AuNPs引导到亚细胞隔间的归巢多肽组成。这些AuNPs将被荧光标记，以可视化它们的亚细胞分布，并将被与111In、67Ga或99mTc络合的聚合物标记。沉积在亚细胞隔室中的放射性数量将通过细胞分级来测量，并用于估计吸收的剂量。剂量将通过蒙特卡罗N粒子(MCNP6)建模计算，然后与亚细胞舱中声发射的放射生物学效应相关联。将通过测定细胞的克隆存活率来研究声发射的放射生物学效应。细胞死亡的机制将通过探测细胞的细胞膜损伤、线粒体膜电位的破坏、核膜损伤引起的微核形成和DNA双链断裂的免疫荧光来研究。我们的长期目标是开发研究细胞内短程辐射影响的工具，并了解人体细胞内辐射的放射生物学和剂量学特性。拟议的研究计划将为三名具有不同专业知识的新研究生(两名博士和一名硕士)提供一个出色的跨学科HQP培训环境，他们将作为一个团队合作开发和表征纳米航天飞机，研究不同亚细胞舱中发射的AEs的放射生物学效应，并对细胞剂量学进行建模。

Auger electrons (AEs) are very low energy electrons (We will engineer novel "nano-shuttle" delivery vehicles to route 111In, 67Ga or 99mTc to the selected subcellular compartments. The nano-shuttles will consist of gold nanoparticles (AuNPs) modified with peptides that target cell surface v3 integrins, and with homing peptides that route the internalized AuNPs to subcellular compartments. The AuNPs will be fluorescently-labeled to visualize their subcellular distribution and will be labeled with polymers that complex 111In, 67Ga or 99mTc. The amount of radioactivity deposited in subcellular compartments will be measured by cell fractionation and used to estimate the absorbed doses. Doses will be calculated by Monte Carlo N-Particle (MCNP6) modeling, and then correlated with the radiobiological effects of AE emission in the subcellular compartments. The radiobiological effects of AE emission will be studied by determining the clonogenic survival of the cells. The mechanism of cell death will be examined by probing the cells for cell membrane damage, disruption of mitochondrial membrane potential, micronucleus formation due to nuclear envelope damage and DNA DSBs by immunofluorescence for -H2AX. Our long-term aim is to develop the tools for studying the effects of short-range radiations in cells, and to understand the radiobiological and dosimetric properties of radiations in human cells. The proposed research program will provide an outstanding trans-disciplinary HQP training environment for 3 new graduate students (two PhD and one MSc) with different expertise who will work collaboratively as a team to develop and characterize the nano-shuttles, study the radiobiological effects of AEs emitted in the different subcellular compartments, and model the cellular dosimetry.