Department of Bioengineering, McGill University, Montreal, Quebec H3A 0E9, Canada.
Research Institute of the McGill University Health Centre (RIMUHC), Montreal, Quebec H4A 3J1, Canada.
ACS Nano. 2023 Jul 11;17(13):12052-12071. doi: 10.1021/acsnano.2c09222. Epub 2023 Jun 27.
Extracellular vesicles (EVs) are continually released from cancer cells into biofluids, carrying actionable molecular fingerprints of the underlying disease with considerable diagnostic and therapeutic potential. The scarcity, heterogeneity and intrinsic complexity of tumor EVs present a major technological challenge in real-time monitoring of complex cancers such as glioblastoma (GBM). Surface-enhanced Raman spectroscopy (SERS) outputs a label-free spectroscopic fingerprint for EV molecular profiling. However, it has not been exploited to detect known biomarkers at the single EV level. We developed a multiplex fluidic device with embedded arrayed nanocavity microchips (MoSERS microchip) that achieves 97% confinement of single EVs in a minute amount of fluid (<10 μL) and enables molecular profiling of single EVs with SERS. The nanocavity arrays combine two featuring characteristics: (1) An embedded MoS monolayer that enables label-free isolation and nanoconfinement of single EVs due to physical interaction (Coulomb and van der Waals) between the MoS edge sites and the lipid bilayer; and (2) A layered plasmonic cavity that enables sufficient electromagnetic field enhancement inside the cavities to obtain a single EV level signal resolution for stratifying the molecular alterations. We used the GBM paradigm to demonstrate the diagnostic potential of the SERS single EV molecular profiling approach. The MoSERS multiplexing fluidic achieves parallel signal acquisition of glioma molecular variants (EGFRvIII oncogenic mutation and MGMT expression) in GBM cells. The detection limit of 1.23% was found for stratifying these key molecular variants in the wild-type population. When interfaced with a convolutional neural network (CNN), MoSERS improved diagnostic accuracy (87%) with which GBM mutations were detected in 12 patient blood samples, on par with clinical pathology tests. Thus, MoSERS demonstrates the potential for molecular stratification of cancer patients using circulating EVs.
细胞外囊泡 (EVs) 不断从癌细胞释放到生物体液中，携带潜在疾病的可操作分子指纹，具有相当大的诊断和治疗潜力。肿瘤 EVs 的稀缺性、异质性和内在复杂性是实时监测胶质母细胞瘤 (GBM) 等复杂癌症的主要技术挑战。表面增强拉曼光谱 (SERS) 输出 EV 分子分析的无标记光谱指纹。然而，它尚未被用于在单个 EV 水平上检测已知的生物标志物。我们开发了一种带有嵌入式阵列纳米腔微芯片 (MoSERS 微芯片) 的多路流体装置，该装置在一小部分 (<10 μL) 流体中实现了 97%的单个 EV 限制，并能够使用 SERS 对单个 EV 进行分子分析。纳米腔阵列结合了两个特点：(1) 嵌入式 MoS 单层，由于 MoS 边缘位点和脂质双层之间的物理相互作用 (库仑和范德华)，能够实现无标记的单个 EV 隔离和纳米限制；(2) 分层等离子体腔，能够在腔体内获得足够的电磁场增强，以获得单个 EV 水平的信号分辨率，从而分层分子改变。我们使用 GBM 范例来证明 SERS 单个 EV 分子分析方法的诊断潜力。MoSERS 多路流体实现了 GBM 细胞中神经胶质瘤分子变体 (EGFRvIII 致癌突变和 MGMT 表达) 的并行信号采集。发现分层这些野生型群体中的关键分子变体的检测限为 1.23%。当与卷积神经网络 (CNN) 接口时，MoSERS 提高了诊断准确性 (87%)，能够在 12 份患者血液样本中检测到 GBM 突变，与临床病理学测试相当。因此，MoSERS 展示了使用循环 EVs 对癌症患者进行分子分层的潜力。
