Detection of Cancer-Specific Proteases Using Magnetic Relaxation of Peptide-Conjugated Nanoparticles in Biological Environment
Detection of Cancer-Specific Proteases Using Magnetic Relaxation of Peptide-Conjugated Nanoparticles in Biological Environment
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DOI：
10.1021/acs.nanolett.6b00867
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发表时间：
2016-06-01
期刊：
影响因子：
10.8
通讯作者：
Krishnan, Kannan M.
中科院分区：
文献类型：
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作者：
Gandhi, Sonu;Arami, Hamed;Krishnan, Kannan M.
蛋白酶表达与不同实体瘤的恶性表型密切相关；因此，它们的检测有望用于癌症、阿尔茨海默病和血管疾病的诊断和治疗。在这里，我们描述了一种通过使用磁粉光谱仪（MPS）灵敏监测单分散氧化铁纳米颗粒（IONP）的磁弛豫来检测蛋白酶的新方法。在该测定中，定制的肽充当可激活的纳米传感器，连接磁性纳米粒子，并具有可被特定蛋白酶识别和切割的选择性位点。当这些在 N 端和 C 端用生物素标记的连接肽添加到中性抗生物素蛋白功能化 IONP 中时，纳米粒子聚集，导致 MPS 信号发生明确的变化。然而，按照设计，在蛋白酶存在的情况下，这些肽在预定位点被切割，重新分散 IONP，并使 MPS 信号返回接近其预聚集状态。在 MPS 信号的各个方面观察到的这些变化（峰值强度、其位置作为场振幅的函数，以及半峰全宽，当组合时，这三者也消除了假阳性），有助于仅依靠功能化纳米颗粒的磁弛豫特性来检测特定的蛋白酶。我们通过检测两种通用蛋白酶中的一种来证明该测定的通用性：胰蛋白酶（消化丝氨酸蛋白酶，参与各种癌症，促进增殖、侵袭和转移）和基质金属蛋白酶（MMP-2，通过转移和肿瘤血管生成观察到）。这种基于 MPS 的蛋白酶测定快速、可重复且高度灵敏，可以为检测各种其他蛋白酶的可行、高通量方法奠定基础。
Protease expression is closely linked to malignant phenotypes of different solid tumors; as such, their detection is promising for diagnosis and treatment of cancers, Alzheimers, and vascular diseases. Here, we describe a new method for detecting proteases by sensitively monitoring the magnetic relaxation of monodisperse iron oxide nanoparticles (IONPs) using magnetic particle spectrometer (MPS). In this assay, tailored peptides functioning as activatable nanosensors link magnetic nanoparticles and possess selective sites that are recognizeable and cleaveable by specific proteases. When these linker peptides, labeled with biotin at N- and C-terminals, are added to the neutravidin functionalized IONPs, nanoparticles aggregate, resulting in well-defined changes in the MPS signal. However, as designed, in the presence of proteases these peptides are cleaved at predetermined sites, redispersing IONPs, and returning the MPS signal(s) close to its preaggregation state. These changes observed in all aspects of the MPS signal (peak intensity, its position as a function of field amplitude, and full width at half-maximumwhen combined, these three also eliminate false positives), help to detect specific proteases, relying only on the magnetic relaxation characteristics of the functionalized nanoparticles. We demonstrate the general utility of this assay by detecting one each from the two general classes of proteases: trypsin (digestive serine protease, involved in various cancers, promoting proliferation, invasion, and metastasis) and matrix metalloproteinase (MMP-2, observed through metastasis and tumor angiogenesis). This MPS based protease-assay is rapid, reproducible, and highly sensitive and can form the basis of a feasible, high-throughput method for detection of various other proteases.