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

我们将设计一种新型的“纳米穿梭”运载工具，将111In、67Ga或99mTc送入选定的亚细胞隔间。纳米穿梭将由靶向细胞表面v3整合素的肽修饰的金纳米颗粒（AuNPs）和将内化AuNPs传递到亚细胞区室的归巢肽组成。将对AuNPs进行荧光标记，以可视化其亚细胞分布，并将用复合111In， 67Ga或99mTc的聚合物进行标记。沉积在亚细胞区室中的放射性量将通过细胞分离来测量，并用于估计吸收剂量。剂量将通过蒙特卡罗n粒子（MCNP6）模型计算，然后与声发射在亚细胞区室中的放射生物学效应相关联。声发射的放射生物学效应将通过测定细胞的克隆性存活来研究。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-H2AX的DNA dsb的免疫荧光来研究。我们的长期目标是开发用于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。拟建的研究项目将为3名具有不同专业知识的新研究生（2名博士和1名硕士）提供一个优秀的跨学科HQP培训环境，他们将作为一个团队合作开发和表征纳米穿梭体，研究不同亚细胞区室发射的ae的放射生物学效应，并建立细胞剂量学模型。

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.