Single cell magnetic microscopy with multicolor superparamagnetic probes.

项目简介：带有多色超顺磁性探针的​单细胞磁性显微镜。 对小肿瘤或单个循环中的肿瘤细胞进行非侵入性成像的能力可能具有 对癌症的早期发现有重大影响。然而，这仍然是一个主要的技术问题 挑战，因为靶细胞必须大量标记具有高度对比剂 特异度和超灵敏成像方式必须保持灵敏度，甚至 当被厚厚的组织分开时。超顺磁性氧化铁纳米颗粒(SPION)是 对于这些目的，由于它们相对无毒和磁场是有希望的 没有被组织衰减的。 我们团队最近开发了一种名为钻石磁性显微镜的技术，能够 在钻石表面~1微米范围内以高空间成像单个22 nm SPION 分辨率(~300 nm)、宽视场(最高可达几毫米)和1 kHz帧速率。在这里我们 提出一项研究计划，将该平台扩展到对免疫磁性标记细胞进行成像 使用多色Spion探针和钻石磁性显微镜。 将使用微流控技术根据松弛时间对SPION的各个颜色进行分类 配有微型磁铁的舱室。我们将把这些探头与 用于两个原理验证实验的金刚石磁性显微镜。在第一部中，两个斯皮恩 将向乳腺癌细胞​体外​引入颜色；其中一批将与 HER2抗体和另一种将被同型匹配的非特异性抗体标记。这个 之后将在不同的时间步长固定细胞，并使用双通道钻石进行成像 磁性显微镜。显微镜可以根据它们的不同来区分Spion的“颜色” 脉冲磁场的时间响应，揭示了亚细胞分布的图像 特定和非特定绑定的SPION。这些数据将被用来揭开 具体的和非具体的内化动态。在第二个实验中，我们将使用 放大版本的钻石磁性显微镜，可检测单个磁性标记的 细胞以生理速率(高达1厘米/S)流过1毫米厚的组织模体。 为了实现这些目标，我们组建了一支实力雄厚的团队，其中包括斯皮恩 化学、癌症生物学和传感器物理学。如果成功，检测平台可以 最终用于检测CTCs和小肿瘤​体内​。

Project Summary: ​Single-cell magnetic microscopy with multicolor superparamagnetic probes. The ability to image small tumors or individual circulating tumor cells non-invasively could have a major impact on the early detection of cancer. However, this remains a major technical challenge, as target cells must be abundantly labeled with contrast agents with a high degree of specificity, and ultra-sensitive imaging modalities must be employed that retain sensitivity even when separated by thick tissue. Superparamagnetic iron-oxide nanoparticles (SPIONs) are promising probes for these purposes, as they are relatively non-toxic and magnetic fields are not attenuated by tissue. Our group has recently developed a technique, diamond magnetic microscopy, capable of imaging individual 22-nm SPIONs within ~1 µm of the diamond surface with high spatial resolution (~300 nm), wide field of view (up to several mm), and >1 kHz frame rate. Here we propose a research program to extend the platform to image immunomagnetically labeled cells using multicolor SPION probes and diamond magnetic microscopy. Individual “colors” of SPIONs will be sorted based on their relaxation times using a microfluidic chamber outfitted with miniature magnets. We will use these probes in combination with diamond magnetic microscopy for two proof-of-principle experiments. In the first, two SPION colors will be introduced to breast cancer cells ​in vitro​; one batch will be functionalized with the Her2 antibody and the other will be labeled with isotype-matched non-specific antibody. The cells will be fixed at various timesteps afterwards and imaged using a dual-channel diamond magnetic microscope. The microscope can differentiate SPION “colors” based on their different temporal response to pulsed magnetic fields, revealing images of the sub-cellular distribution of specific and non-specifically-bound SPIONs. These data will be used to unravel the evolution of specific and non-specific internalization dynamics. In the second experiment, we will use a scaled-up version of the diamond magnetic microscope to detect individual magnetically-labeled cells flowing at physiological rates (up to 1 cm/s) through a 1-mm-thick tissue phantom. To accomplish these aims, we have assembled a team with broad strengths, including SPION chemistry, cancer biology, and sensor physics. If successful, the detection platform may eventually be used to detect CTCs and small tumors ​in vivo​.