Stem Cell Research Center, Tabriz University of Medical Sciences, Tabriz, Iran.
Department of Applied Cell Sciences, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran.
Stem Cell Res Ther. 2024 Nov 26;15(1):453. doi: 10.1186/s13287-024-04005-7.
Extracellular vesicles (EVs) have been considered promising tools in regenerative medicine. However, the nanoscale properties of EVs make them sensitive to environmental conditions. Optimal storage protocols are crucial for maintaining EV structural, molecular, and functional integrity. This systematic review aimed to gather evidence on the effects of various storage protocols on EV characteristics and integrity.
A comprehensive search was conducted for original studies investigating the impacts of storage temperature, freezing techniques, freeze-thaw cycles, and stabilizing strategies on EV concentration, size distribution, morphology, cargo content, and bioactivity. Results from 50 included studies were analyzed.
Data indicated that rapid freezing procedures and constant subzero temperatures (optimally - 80 °C) resulted in appropriate EV quantity and cargo preservation. Subjecting EVs to multiple freeze-thaw cycles decreased particle concentrations, RNA content, impaired bioactivity, and increased EV size and aggregation. Electron microscopy revealed vesicle enlargement, and fusion, along with membrane deformation after being exposed to substandard storage protocols. The addition of stabilizers like trehalose helped EVs to maintain integrity. Of note, storage in native biofluids offered improved stability over purified EVs in buffers.
Data emphasize the critical need for precise storage protocols for EVs to ensure reproducible research outcomes and clinical applications. Further studies using reliable methods are necessary to create specific guidelines for improving the stability of EVs in various applications.
细胞外囊泡 (EVs) 已被认为是再生医学中有前途的工具。然而，EV 的纳米级特性使它们对环境条件敏感。最佳的储存方案对于保持 EV 的结构、分子和功能完整性至关重要。本系统评价旨在收集关于各种储存方案对 EV 特性和完整性影响的证据。
对研究储存温度、冷冻技术、冻融循环和稳定化策略对 EV 浓度、大小分布、形态、货物含量和生物活性影响的原始研究进行了全面检索。分析了 50 项纳入研究的结果。
数据表明，快速冷冻程序和恒定的亚零温度（最佳-80°C）可使 EV 的数量和货物得到适当的保存。使 EV 经受多次冻融循环会降低颗粒浓度、RNA 含量、损害生物活性，并增加 EV 的大小和聚集。电子显微镜显示，在不符合标准的储存方案下，囊泡会发生膨胀、融合以及膜变形。添加稳定剂如海藻糖有助于 EV 保持完整性。值得注意的是，与在缓冲液中相比，在天然生物液中储存可提高 EV 的稳定性。
数据强调了为 EV 制定精确储存方案的重要性，以确保可重复的研究结果和临床应用。需要使用可靠的方法进行进一步研究，以制定各种应用中提高 EV 稳定性的具体指南。
