Bebesi Tímea, Pálmai Marcell, Szigyártó Imola Csilla, Gaál Anikó, Wacha András, Bóta Attila, Varga Zoltán, Mihály Judith
Institute of Materials and Environmental Chemistry, HUN-REN Research Centre for Natural Sciences (RCNS), Magyar tudósok körútja 2, Budapest 1117, Hungary; Hevesy György PhD School of Chemistry, Eötvös Lóránd University, Pázmány Péter sétány 1/A, Budapest 1117, Hungary.
Institute of Materials and Environmental Chemistry, HUN-REN Research Centre for Natural Sciences (RCNS), Magyar tudósok körútja 2, Budapest 1117, Hungary.
Colloids Surf B Biointerfaces. 2025 Feb;246:114366. doi: 10.1016/j.colsurfb.2024.114366. Epub 2024 Nov 7.
Extracellular vesicles (EVs), sub-micrometer lipid-bound particles released by most cells, are considered a novel area in both biology and medicine. Among characterization methods, infrared (IR) spectroscopy, especially attenuated total reflection (ATR), is a rapidly emerging label-free tool for molecular characterization of EVs. The relatively low number of vesicles in biological fluids (∼10 particle/mL), however, and the complex content of the EVs' milieu (protein aggregates, lipoproteins, buffer molecules) might result in poor signal-to-noise ratio in the IR analysis of EVs. Exploiting the increment of the electromagnetic field at the surface of plasmonic nanomaterials, surface-enhanced infrared spectroscopy (SEIRS) provides an amplification of characteristic IR signals of EV samples. Negatively charged citrate-capped and positively charged cysteamine-capped gold nanoparticles with around 10 nm diameter were synthesized and tested with blood-derived EVs. Both types of gold nanoparticles contributed to an enhancement of the EVs' IR spectroscopic signature. Joint evaluation of UV-Vis and IR spectroscopic results, supported by FF-TEM images, revealed that proper interaction of gold nanoparticles with EVs is crucial, and an aggregation or clustering of gold nanoparticles is necessary to obtain the SEIRS effect. Positively charged gold nanoparticles resulted in higher enhancement, probably due to electrostatic interaction with EVs, commonly negatively charged.
细胞外囊泡（EVs）是大多数细胞释放的亚微米级脂质结合颗粒，被认为是生物学和医学领域的一个新领域。在表征方法中，红外（IR）光谱，尤其是衰减全反射（ATR）光谱，是一种迅速兴起的用于EVs分子表征的无标记工具。然而，生物流体中囊泡数量相对较少（约10个颗粒/毫升），且EVs环境的成分复杂（蛋白质聚集体、脂蛋白、缓冲分子），这可能导致EVs的红外分析中信噪比不佳。利用等离子体纳米材料表面的电磁场增强，表面增强红外光谱（SEIRS）可放大EVs样品的特征红外信号。合成了直径约10纳米的带负电荷的柠檬酸盐包覆和带正电荷的半胱胺包覆的金纳米颗粒，并用于测试血液来源的EVs。两种类型的金纳米颗粒都有助于增强EVs的红外光谱特征。在FF-TEM图像的支持下，对紫外-可见光谱和红外光谱结果进行联合评估，结果表明金纳米颗粒与EVs的适当相互作用至关重要，并且金纳米颗粒的聚集或簇集是获得SEIRS效应所必需的。带正电荷的金纳米颗粒产生了更高的增强效果，这可能是由于与通常带负电荷的EVs发生静电相互作用所致。
