Background

Extracellular vesicles (EVs) are cell-derived nanometric particles governing the complex interactions among cells through their bioactive cargo. Interest in EVs is rapidly increasing due to their extensive involvement in physiological and pathological conditions, their potential employment as diagnostic and therapeutic tools and their prospective use as bio-carriers of exogenous molecules. Given their nanometric size, transmission electron microscopy (TEM) provides significant contributions to assess EV presence and purity in a sample and to study morphological features.

Scope of review

In this review, TEM methods for EV imaging are compared with respect to their applications, benefits and drawbacks. A critical evaluation of the actual contribution of TEM to the study of EVs is also provided and the most common artifacts encountered in the literature are discussed.

Major conclusions

TEM techniques are powerful tools for the investigation of EVs and have the potential to reveal sample purity, ultrastructure and molecular composition. However, technical challenges, procedural errors in sample processing or misinterpretations may result in a variety of different morphologies and artifacts.

General significance

The last decades have seen exponential technological progress in EV imaging by TEM. Nevertheless, protocols have not been standardized yet and sample preparation remains a critical step. An optimized, standardized and integrated protocol of different techniques could minimize artifacts and interpretative errors that could significantly improve the quality and reliability of downstream studies.

中文翻译：

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通过透射电子显微镜成像细胞外囊泡：应对技术障碍和形态学解释。

背景

细胞外囊泡（EVs）是细胞衍生的纳米粒子，通过其生物活性物质控制细胞之间的复杂相互作用。由于电动汽车广泛参与生理和病理状况，其作为诊断和治疗工具的潜在用途以及作为外源分子的生物载体的潜在用途，因此对电动汽车的兴趣正迅速增加。鉴于其纳米尺寸，透射电子显微镜（TEM）为评估样品中EV的存在和纯度以及研究形态特征做出了重要贡献。

审查范围

在这篇综述中，针对电动汽车成像的TEM方法的应用，优缺点进行了比较。还提供了对TEM对电动汽车研究的实际贡献的重要评估，并讨论了文献中遇到的最常见工件。

主要结论

TEM技术是研究电动汽车的有力工具，具有揭示样品纯度，超微结构和分子组成的潜力。但是，技术挑战，样品处理中的程序错误或曲解可能会导致各种不同的形态和伪像。

一般意义

在过去的几十年中，通过TEM在电动汽车成像方面取得了指数级的技术进步。然而，方案尚未标准化，样品制备仍是关键步骤。不同技术的优化，标准化和集成协议可以最大程度地减少工件和解释错误，从而可以显着提高下游研究的质量和可靠性。