Park Jaesook, Estrada Arnold, Schwartz Jon A, Diagaradjane Parmeswaran, Krishnan Sunil, Dunn Andrew K, Tunnell James W
Department of Biomedical Engineering, The University of Texas at Austin, Texas.
Lasers Surg Med. 2010 Sep;42(7):630-639. doi: 10.1002/lsm.20935.
Gold nanoparticles (GNPs) such as gold nanoshells (GNSs) and gold nanorods (GNRs) have been explored in a number of in vitro and in vivo studies as imaging contrast and cancer therapy agents due to their highly desirable spectral and molecular properties. While the organ-level biodistribution of these particles has been reported previously, little is known about the cellular level or intra-organ biodistribution. The objective of this study was to demonstrate the use of intrinsic two-photon induced photoluminescence (TPIP) to study the cellular level biodistribution of GNPs. STUDY DESIGN/MATERIALS AND METHODS: Tumor xenografts were created in twenty-seven male nude mice (Swiss nu/nu) using HCT 116 cells (CCL-247, ATCC, human colorectal cancer cell line). GNSs and GNRs were systemically injected 24 hr. prior to tumor harvesting. A skin flap with the tumor was excised and sectioned as 8 μm thick tissues for imaging GNPs under a custom-built multiphoton microscope. For multiplexed imaging, nuclei, cytoplasm, and blood vessels were demonstrated by hematoxylin and eosin (H&E) staining, YOYO-1 iodide staining and CD31-immunofluorescence staining. RESULTS: Distribution features of GNPs at the tumor site were determined from TPIP images. GNSs and GNRs had a heterogeneous distribution with higher accumulation at the tumor cortex than tumor core. GNPs were also observed in unique patterns surrounding the perivascular region. While most GNSs were confined at the distance of approximately 400 μm inside the tumor edge, GNRs were shown up to 1.5 mm penetration inside the edge. CONCLUSIONS: We have demonstrated the use of TPIP imaging in a multiplexed fashion to image both GNPs and nuclei, cytoplasm, or vasculature simultaneously. We also confirmed that TPIP imaging enabled visualization of GNP distribution patterns within the tumor and other critical organs. These results suggest that direct luminescence-based imaging of metal nanoparticles holds a valuable and promising position in understanding the accumulation kinetics of GNPs. In addition, these techniques will be increasingly important as the use of these particles progress to human clinical trials where standard histopathology techniques are used to analyze their effects.
金纳米颗粒（GNPs），如金纳米壳（GNSs）和金纳米棒（GNRs），因其具有高度理想的光谱和分子特性，已在多项体外和体内研究中被探索用作成像造影剂和癌症治疗剂。虽然此前已报道了这些颗粒在器官水平的生物分布，但对于细胞水平或器官内生物分布却知之甚少。本研究的目的是证明利用固有双光子诱导光致发光（TPIP）来研究GNPs的细胞水平生物分布。
研究设计/材料与方法：使用HCT 116细胞（CCL - 247，ATCC，人结肠癌细胞系）在27只雄性裸鼠（瑞士nu/nu）中建立肿瘤异种移植模型。在收获肿瘤前24小时全身注射GNSs和GNRs。切除带有肿瘤的皮瓣并切成8μm厚的组织，在定制的多光子显微镜下对GNPs进行成像。对于多重成像，通过苏木精和伊红（H&E）染色、YOYO - 1碘化物染色和CD31免疫荧光染色来显示细胞核、细胞质和血管。
从TPIP图像确定了GNPs在肿瘤部位的分布特征。GNSs和GNRs分布不均，在肿瘤皮质比肿瘤核心积累更多。在血管周围区域也观察到GNPs呈独特模式分布。虽然大多数GNSs局限于肿瘤边缘内约400μm的距离内，但GNRs显示在边缘内可穿透达1.5mm。
我们已证明以多重方式使用TPIP成像可同时对GNPs与细胞核、细胞质或脉管系统进行成像。我们还证实TPIP成像能够可视化肿瘤和其他关键器官内GNP的分布模式。这些结果表明，基于直接发光的金属纳米颗粒成像在理解GNPs的积累动力学方面具有重要且有前景的地位。此外，随着这些颗粒在人类临床试验中的应用进展，在使用标准组织病理学技术分析其效果时，这些技术将变得越来越重要。
