Division of Cardiovascular Surgery, Department of Surgery, University of Pennsylvania.
Department of Bioengineering, University of Pennsylvania.
Int Heart J. 2021 Mar 30;62(2):381-389. doi: 10.1536/ihj.20-224. Epub 2021 Mar 17.
Extracellular vesicles (EV) that are derived from endothelial progenitor cells (EPC) have been determined to be a novel therapy for acute myocardial infarction, with a promise for immediate "off-the-shelf" delivery. Early experience suggests delivery of EVs from allogeneic sources is safe. Yet, clinical translation of this therapy requires assurances of both EV stability following cryopreservation and absence of an adverse immunologic response to EVs from allogeneic donors. Thus, more bioactivity studies on allogeneic EVs after cold storage are necessary to establish quality standards for its widespread clinical use. Thus, in this study, we aimed to demonstrate the safety and efficacy in delivering cryopreserved EVs in allogeneic recipients as a therapy for acute myocardial infarction.In this present study, we have analyzed the cardioprotective effects of allogeneic EPC-derived EVs after storage at -80°C for 2 months, using a shear-thinning gel (STG) as an in vivo delivery vehicle. EV size, proteome, and nucleic acid cargo were observed to remain steady through extended cryopreservation via nanoparticle tracking analysis, mass spectrometry, and nanodrop analysis, respectively. Fresh and previously frozen EVs in STG were delivered intramyocardially in a rat model of myocardial infarction (MI), with both showing improvements in contractility, angiogenesis, and scar thickness in comparison to phosphate-buffered saline (PBS) and STG controls at 4 weeks post-MI. Pathologic analyses and flow cytometry revealed minimal inflammatory and immune upregulation upon exposure of tissue to EVs pooled from allogeneic donor cells.Allogeneic EPC-EVs have been known to elicit minimal immune activity and retain therapeutic efficacy after at least 2 months of cryopreservation in a post-MI model.
细胞外囊泡（EV）来源于内皮祖细胞（EPC），已被确定为急性心肌梗死的一种新疗法，具有即时“即用型”输送的潜力。早期经验表明，同种异体来源的 EV 输送是安全的。然而，这种治疗方法的临床转化需要保证 EV 在冷冻保存后保持稳定，并且同种异体供体的 EV 不会引起不良反应的免疫应答。因此，需要对冷冻保存后的同种异体 EV 进行更多的生物活性研究，以建立其广泛临床应用的质量标准。因此，在这项研究中，我们旨在证明在同种异体受者中输送冷冻保存的 EV 作为急性心肌梗死治疗的安全性和有效性。
在本研究中，我们使用剪切稀化凝胶（STG）作为体内输送载体，分析了储存于-80°C 2 个月后的同种异体 EPC 衍生 EV 的心脏保护作用。通过纳米颗粒跟踪分析、质谱和纳米滴分析，分别观察到 EV 的大小、蛋白质组和核酸货物在延长的冷冻保存过程中保持稳定。新鲜和先前冷冻的 EV 在 STG 中被递送至心肌梗死（MI）大鼠模型的心肌内，与磷酸盐缓冲盐水（PBS）和 STG 对照组相比，两者在 MI 后 4 周时均显示出收缩性、血管生成和疤痕厚度的改善。病理分析和流式细胞术显示，组织暴露于同种异体供体细胞来源的 EV 后，炎症和免疫上调最小。
同种异体 EPC-EV 已知在至少 2 个月的冷冻保存后在 MI 模型中引起最小的免疫活性并保持治疗效果。
