Tumor-targeted delivery and cell internalization of theranostic gadolinium nanoparticles for image-guided nanoparticle-enhanced radiation therapy

用于图像引导纳米颗粒增强放射治疗的治疗诊断钆纳米颗粒的肿瘤靶向递送和细胞内化

• 批准号: 10017981
• 负责人: Wu Liu
• 金额: $ 18.27万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-13 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10017981
• 关键词: Acidity; Antibodies; Antibody Therapy; Autopsy; Biodistribution; Biological; Biological Assay; Biological Markers; Breast Cancer Model; Cell Culture Techniques; Cell Death; Cell Survival; Cell membrane; Cells; Chelating Agents; Clinical; Clinical Chemistry; Clinical Research; Comet Assay; Complement; Computer Simulation; Conformal Radiotherapy; DNA Damage; Data; Development; Diagnostic; Dose; Electrons; Endocytosis; Foundations; France; Gadolinium; Gamma-H2AX; Geometry; Goals; Hematology; Histopathology; Hour; Image; Imaging problem; In Vitro; Inductively Coupled Plasma Mass Spectrometry; Injections; Laboratory Research; Lead; Link; Magnetic Resonance Imaging; Malignant neoplasm of lung; Measures; Microscopic; Mitochondrial DNA; Modeling; Mus; Neoplasm Metastasis; Normal tissue morphology; Nuclear; Organ; Pathway interactions; Patients; Peptides; Permeability; Pharmacology; Physiological; Property; Radiation; Radiation therapy; Radiation-Sensitizing Agents; Radiosensitization; Research; Research Design; Resistance; Roentgen Rays; Signal Transduction; Solid Neoplasm; Structure; System; Techniques; Testing; Therapeutic; Time; Tissues; Toxic effect; Translating; Translations; Weight; Work; Xenograft procedure; aggressive therapy; base; biophysical model; biophysical properties; cancer cell; cell killing; cellular imaging; cellular targeting; clinical application; clinical translation; clinically relevant; experimental study; human model; image guided; imaging properties; improved; in vivo; interest; metallicity; microscopic imaging; mouse model; nanoparticle; nanoparticle delivery; neoplastic cell; novel; p53-binding protein 1; particle; pre-clinical; prevent; quantitative imaging; residence; response; simulation; targeted biomarker; targeted delivery; theranostics; translational study; treatment planning; treatment response; tumor; tumor growth; tumor microenvironment; tumor specificity; uptake

The long-term objective of this project is to overcome some of the major hurdles that prevent the clinical translation of metallic nanoparticle (NP) radiosensitization in radiation therapy (RT). Studies have shown that the passive, enhanced permeability and retention (EPR) effect itself is not sufficient to deliver the amount of intratumoral and intracellular NPs needed for in vivo radiosensitization with an affordable amount of injected NPs and the conventional NPs are cleared rapidly (~minutes) in vivo. Imaging the in vivo NP biodistribution for quantitative RT treatment planning is also an unsolved critical issue. Actively targeting and internalization into cancer cells by gadolinium (Gd) NPs conjugated to pH-Low Insertion Peptides (pHLIPs) have the potential to serve the dual purpose of enhancing uptake of NPs in tumor cells and selective, quantitative imaging by MRI. pHLIP-GdNPs can actively target solid tumors’ unavoidable acidic microenvironment, which is not present in healthy tissues. Therefore, it is superior to other biomarker targeting, such as antibody targeting, which can become nonspecific and be evaded by selection of non-expressing subclones during treatment. pHLIPs can also deliver the conjugated cell-impermeable cargoes inside the cancer cells via a strong non-endocytic pathway, critical for NP-induced short-range Auger cascade and photoelectrons to reach the vital cellular targets as proved by experiments and simulations. Complementing the rapid increasing use of MRI for RT planning and on-board treatment-guidance, pHLIP-GdNPs can also solve the imageability problem for treatment plan optimization. Our preliminary MRI data shows long tumor retention of NPs (>9 hours, possibly days) post pHLIP-GdNPs injection. Specific Aims: To provide the pre-clinical foundation for more in-depth translational and clinical studies, we aim to (i) characterize pHLIP-GdNP and evaluate its RT properties in vitro; (ii) develop a mechanistic biophysical model of radiosensitization by GdNPs to elucidate relevant biolgocial mechanisms and facilitate quantitative RT treatment planning; and (iii) investigate the in vivo radiosensitization and imaging properties of pHLIP-GdNP. Research Design: (i) Characterize pHLIP-GdNP and internalization, microscopically image cellular uptake with fluorescent tags, conduct clonogenic survival experiments in cell culture with both 250 kVp and 6 MV X-rays, generate pH-dependent cell survival curves, and examine DNA damage. (ii) Use a Monte Carlo particle track structure simulation to calculate microscopic dose enhancement induced by NPs. DNA damage will be modeled to predict sensitizer enhancement ratios and compare with experimental results. (iii) Investigate the feasibility of MR imaging to determine quantitatively in vivo NP distribution and the residence-transit time in tumor and critical organs in mouse models, the enhanced radiosensitization in vivo in mice injected with pHLIP-GdNPs compared to mice injected with untargeted GdNPs using tumor growth delay assay, and the in vivo toxicity of pHLIP-GdNPs. Impact: This project can lead to a novel theranostic agent that offers improved therapeutic ratio and imageability. This new paradigm of NP delivery and imaging can a have broad impact in image-guided NP-enhanced RT.

该项目的长期目标是克服阻碍临床应用的一些主要障碍 金属纳米粒子（NP）放射增敏在放射治疗（RT）中的翻译 研究表明， 被动、增强渗透性和保留 (EPR) 效应本身不足以提供一定量的 体内放射增敏所需的肿瘤内和细胞内纳米颗粒，注射量可承受 常规 NP 在体内快速（约分钟）被清除，对体内 NP 生物分布进行成像。 定量 RT 治疗计划也是一个未解决的关键问题，积极瞄准并内化。 与 pH 低插入肽 (pHLIP) 缀合的钆 (Gd) 纳米粒子有潜力 具有增强肿瘤细胞对 NP 的摄取和通过 MRI 进行选择性定量成像的双重目的。 pHLIP-GdNPs 可以主动靶向实体瘤不可避免的酸性微环境，而实体瘤中不存在这种微环境。 因此，它优于其他生物标志物靶向，例如抗体靶向。 pHLIP 可能变得非特异性，并且可以通过在治疗期间选择非表达亚克隆来逃避。 还通过强大的非内吞途径将结合的细胞不可渗透的货物递送到癌细胞内， 经证实，对于 NP 诱导的短程俄歇级联和光电子到达重要的细胞目标至关重要 通过实验和模拟补充 MRI 在 RT 规划和机载中的快速增长的使用。 治疗指导，pHLIP-GdNPs 还可以解决治疗计划优化的成像问题。 初步 MRI 数据显示注射 pHLIP-GdNPs 后 NPs 在肿瘤中保留较长时间（> 9 小时，可能是几天）。 具体目标：为了为更深入的转化和临床研究提供临床前基础，我们的目标 (i) 表征 pHLIP-GdNP 并评估其体外 RT 特性；(ii) 开发机械生物物理方法； GdNP 放射增敏模型，以阐明相关生物机制并促进定量 RT 治疗计划；(iii) 研究 pHLIP-GdNP 的体内放射增敏和成像特性。 研究设计：(i) 表征 pHLIP-GdNP 和内化，用显微镜对细胞摄取进行成像 荧光标签，使用 250 kVp 和 6 MV X 射线在细胞培养物中进行克隆存活实验， (ii) 使用蒙特卡罗粒子轨迹 将模拟计算由 NP 引起的微观剂量增强。 预测敏化剂增强率并与实验结果进行比较 (iii) 研究可行性。 MR 成像可定量确定体内 NP 分布以及在肿瘤和关键部位的停留-传输时间 在小鼠模型的器官中，与注射 pHLIP-GdNPs 的小鼠相比，体内放射增敏作用增强 使用肿瘤生长延迟测定对注射非靶向 GdNP 的小鼠进行研究，以及 pHLIP-GdNP 的体内毒性。 影响：该项目可以开发出一种新型治疗诊断剂，可提高治疗率和成像能力。 这种 NP 递送和成像的新范例可以对图像引导的 NP 增强 RT 产生广泛影响。