In vivo CT imaging of gold nanoparticle-labeled exosomes in a myocardial infarction mouse model.

Acute myocardial infarction (MI) is the primary factor leading to cardiovascular diseases, which are the main causes of morbidity and mortality in developed countries. Mesenchymal stem cell (MSC)-derived exosomes have been reported to improve heart function after MI; however, the molecular mechanisms responsible for this are unknown. In vivo imaging can reveal the trafficking process and in vivo biodistribution of exosomes, which may provide an insight into the communication mechanisms and pharmacokinetics of exosomes. Glucose modified gold nanoparticles were used to label MSC-derived exosomes, aimed at minimizing membrane damage and maintaining the integrity of the exosomes. After labeling, the exosomes were visualized by in vivo computed tomography (CT) imaging to determine the biodistribution at 4 and 24 h after injection into a MI mouse model. MSC-derived exosomes were successfully labeled by glucose modified gold nanoparticles and CT imaging of these labeled exosomes indicated that MSC-Exo remained in the MI area for up to 24 h after intramyocardial injection. Additionally, few MSC-Exo were observed in some other organs, particularly the liver, spleen, and kidney. A gentle method was used for loading GNPs into exosomes, and their successful labeling without causing aggregation was verified. In vivo CT imaging revealed the retention of MSC-Exo in the MI area, indicating their usefulness for improving heart function after infarction.

急性心肌梗死（MI）是导致心血管疾病的首要因素，而心血管疾病是发达国家发病和死亡的主要原因。间充质干细胞（MSC）衍生的外泌体据报道可改善心肌梗死后的心脏功能；然而，其相关分子机制尚不清楚。体内成像能够揭示外泌体的运输过程和体内生物分布，这可能为了解外泌体的通讯机制和药代动力学提供见解。 利用葡萄糖修饰的金纳米粒子标记MSC衍生的外泌体，目的是尽量减少膜损伤并保持外泌体的完整性。标记后，通过体内计算机断层扫描（CT）成像观察外泌体，以确定在注射到心肌梗死小鼠模型后4小时和24小时的生物分布。 葡萄糖修饰的金纳米粒子成功标记了MSC衍生的外泌体，并且对这些标记外泌体的CT成像表明，心肌内注射后，MSC - 外泌体在心肌梗死区域可留存长达24小时。此外，在一些其他器官，特别是肝脏、脾脏和肾脏中观察到的MSC - 外泌体很少。 采用了一种温和的方法将金纳米粒子载入外泌体，并验证了它们在不引起聚集的情况下成功标记。体内CT成像揭示了MSC - 外泌体在心肌梗死区域的留存，表明它们对改善梗死后心脏功能是有用的。