Magnetic relaxation switch detection of human chorionic gonadotrophin
Magnetic relaxation switch detection of human chorionic gonadotrophin
复制标题
DOI：
10.1021/bc070110w
复制
发表时间：
2007-11-01
影响因子：
4.7
通讯作者：
Cima, Michael J.
中科院分区：
文献类型：
--
作者：
Kim, Grace Y.;Josephson, Lee;Cima, Michael J.
功能化的纳米颗粒造影剂，也称为磁弛豫开关（MRS），被制备用于检测蛋白A和人绒毛膜促性腺激素（hCG-β）的β亚基。使用标准肽化学将抗体连接到交联的氧化铁（克利奥）纳米颗粒。蛋白A用作简单的模型分析物，因为它是天然多价的并且可以同时结合多种CLIO-IgG。如通过NMR弛豫测定法测量所见，与空白对照相比，向CLIO-IgG中添加PA导致横向弛豫时间（T-2）缩短。通过光散射粒度分析证实分析物诱导的聚集。设计了一个双粒子系统来测量hCG-β，因为它不是多价的，需要将一对匹配的单克隆抗体与克利奥（称为C95和C97）偶联。hCG-β的测量很重要，因为血清水平升高与恶性肿瘤（包括睾丸癌和卵巢癌）有关。向C95和C97中添加hCG-β导致T-2缩短，线性动态浓度范围为每个纳米颗粒0.1至1个分析物分子。对于hCG二聚体获得了类似的数据。还观察到分析物与纳米颗粒的化学计量比更高以及纳米颗粒化合价增加。这种方法可以潜在地适用于检测溶液中的其他生物标志物。
Functionalized nanoparticle contrast agents, also known as magnetic relaxation switches (MRS), were prepared to detect protein A and the beta subunit of human chorionic gonadotrophin (hCG-beta). Antibodies were attached to cross-linked iron oxide (CLIO) nanoparticles using standard peptide chemistry. Protein A was used as a simple model analyte, as it is naturally multivalent and can bind multiple CLIO-IgG simultaneously. The addition of PA to CLIO-IgG resulted in transverse relaxation time (T-2) shortening compared to a blank control as seen by NMR relaxometry measurements. Analyte-induced aggregation was confirmed by light scattering particle size analysis. A two-particle system was designed to measure hCG-beta, as it is not multivalent and requires conjugation of a matched pair of monoclonal antibodies to CLIO (referred to as C95 and C97). Measurement of hCG-beta is important, as elevated serum levels are associated with malignancies including testicular and ovarian cancers. The addition of hCG-beta to C95 and C97 resulted in T-2 shortening with a linear dynamic concentration range of 0.1 to 1 molecules of analyte per nanoparticle. Similar data were obtained for the hCG dimer. Observations with higher stoichiometric ratios of analyte to nanoparticle and increased nanoparticle valency were also made. This method can potentially be adapted to detect other biomarkers in solution.