Nanotechnologies for Cellular and Molecular Imaging by MRI
Nanotechnologies for Cellular and Molecular Imaging by MRI
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DOI：
10.1002/3527603476.ch9
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发表时间：
2005-01-01
期刊：
影响因子：
--
通讯作者：
Lanza, Gregory M.
中科院分区：
文献类型：
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作者：
Winter, Patrick M.;Caruthers, Shelton D.;Lanza, Gregory M.
细胞和分子生物学的发展正在将医学成像的范围从大体解剖描述扩展到描绘细胞和生化信号传导过程。细胞和分子成像的新兴领域旨在基于复杂病理过程的体内检测和表征（例如炎症或血管生成的诱导）来非侵入性地诊断疾病。最近已经开发了技术，以实现分子和细胞成像与大多数成像方式，包括核[1，2]，光学[2，3]，超声[4]和MRI [5，6]。本章重点介绍了两种通过MRI检测动脉粥样硬化的技术：与炎性病变相关的巨噬细胞的细胞成像和在发展中的血管斑块中诱导的血管生成的分子成像。造影剂配方和成像方法的选择将被讨论，以及这些技术的优化成功的细胞和分子imaging in vivo.Because单个细胞和生化分子太小，无法直接成像与非侵入性技术，具体和敏感的位点靶向造影剂是需要可视化的感兴趣的表位。在历史上，由于将放射性标签缀合到生物化学分子上的极高灵敏度和相对简单性，核成像已经主导了细胞和分子成像领域。例如，氟脱氧葡萄糖（FDG）活性可以用PET扫描仪成像，以表征肿瘤代谢[7]和精神障碍[8]等不同疾病状态。还开发了放射性标记的生长抑素类似物，以允许受体成像用于检测神经内分泌肿瘤[9]。此外，可以用锝标记的膜联蛋白-V检测细胞凋亡，膜联蛋白-V与凋亡细胞表面表达的磷脂酰丝氨酸结合[10]。核成像剂也被设计成通过对所得蛋白质产物成像来检测基因转染[11]。
Developments in cellular and molecular biology are extending the horizons of medical imaging from gross anatomic description towards delineation of cellular and biochemical signaling processes. The emerging fields of cellular and molecular imaging aim to diagnose disease noninvasively on the basis of in vivo detection and characterization of complex pathological processes, such as induction of inflammation or angiogenesis. Techniques have been developed recently to achieve molecular and cellular imaging with most imaging modalities, including nuclear [1, 2], optical [2, 3], ultrasound [4], and MRI [5, 6]. This chapter focuses on two techniques developed for detection of atherosclerosis by MRI: cellular imaging of macrophages associated with inflammatory lesions and molecular imaging of angiogenesis that is induced in developing vascular plaques. A selection of the contrast agent formulation and imaging methods will be discussed, as well as the optimization of these techniques for successful cellular and molecular imaging in vivo.Because individual cells and biochemical molecules are too small to be imaged directly with noninvasive techniques, specific and sensitive site-targeted contrast agents are needed to visualize the epitopes of interest. Historically, nuclear imaging has dominated the fields of cellular and molecular imaging due to the extremely high sensitivity and the relative simplicity of conjugating radioactive tags onto biochemical molecules. For instance, fluorodeoxyglucose (FDG) activity can be imaged with PET scanners to characterize such diverse disease states as tumor metabolism [7] and mental disorders [8]. Radiolabeled somatostatin analogs have also been developed to allow receptor imaging for detection of neuroendocrine tumors [9]. In addition, cellular apoptosis can be detected with technetium-labeled annexin-V, which binds to phosphatidyl serine expressed on the surface of apoptotic cells [10]. Nuclear imaging agents have also been designed to detect gene transfection by imaging the resultant protein products [11].