Department of Molecular and Translational Medicine and INSTM, University of Brescia, Viale Europa, 11, 25132 Brescia, Italy.
Department of Molecular and Translational Medicine and INSTM, University of Brescia, Viale Europa, 11, 25132 Brescia, Italy.
Biosens Bioelectron. 2016 Mar 15;77:518-24. doi: 10.1016/j.bios.2015.09.061. Epub 2015 Oct 3.
A novel approach for sorting exosomes from multiple myeloma (MM), monoclonal gammopathy of undetermined significance (MGUS) and healthy individuals is presented. The method is based on the combination of colloidal gold nanoplasmonics and surface plasmon resonance (SPR) biosensing and probes distinctive colloidal properties of MM-derived exosomes, such as molar concentration and cell membrane binding preferences. It allowed to discover that MM patients produce about four folds more exosomes than MGUS and healthy individuals. In addition, it showed that among the analyzed exosomes, only the MM-derived ones bind heparin - a structural analog of heparan sulfate proteoglycans known to mediate exosome endocytosis - with an apparent dissociation constant (Kd) equal to about 1 nM, indicating a high affinity binding. This plasmonic method complements the classical biochemical profiling approach to exosomes, expanding the MM biomarker panel and adding biosensors to the toolbox to diagnose MM. It may find applications for other diseases and has wider interest for fundamental and translational research involving exosomes.
一种从多发性骨髓瘤（MM）、意义未明的单克隆丙种球蛋白病（MGUS）和健康个体中分离外泌体的新方法被提出。该方法基于胶体金纳米等离子体学和表面等离子体共振（SPR）生物传感的结合，并利用 MM 来源的外泌体独特的胶体性质作为探针，例如摩尔浓度和细胞膜结合偏好。该方法发现，MM 患者产生的外泌体比 MGUS 和健康个体多约四倍。此外，它表明在所分析的外泌体中，只有 MM 来源的外泌体与肝素结合，肝素是一种硫酸乙酰肝素蛋白聚糖的结构类似物，已知其介导外泌体的内吞作用，其表观解离常数（Kd）约等于 1 nM，表明具有高亲和力结合。这种等离子体方法补充了外泌体的经典生化分析方法，扩展了 MM 生物标志物面板，并为诊断 MM 添加了生物传感器。它可能适用于其他疾病，并为涉及外泌体的基础和转化研究提供了更广泛的兴趣。
