Engineering Cardiac Small Extracellular Vesicle-Derived Vehicles with Thin-Film Hydration for Customized microRNA Loading.

Sruti Bheri,Jessica R Hoffman,Hyun-Ji Park,Brandon P Kassouf,Michael E Davis

doi:10.3390/jcdd8110135

Abstract

Cell therapies for myocardial infarction, including cardiac ckit+ progenitor cell (CPC) therapies, have been promising, with clinical trials underway. Recently, paracrine signaling, specifically through small extracellular vesicle (sEV) release, was implicated in cell-based cardiac repair. sEVs carry cardioprotective cargo, including microRNA (miRNA), within a complex membrane and improve cardiac outcomes similar to that of their parent cells. However, miRNA loading efficiency is low, and sEV yield and cargo composition vary with parent cell conditions, minimizing sEV potency. Synthetic mimics allow for cargo-loading control but consist of much simpler membranes, often suffering from high immunogenicity and poor stability. Here, we aim to combine the benefits of sEVs and synthetic mimics to develop sEV-like vesicles (ELVs) with customized cargo loading. We developed a modified thin-film hydration (TFH) mechanism to engineer ELVs from CPC-derived sEVs with pro-angiogenic miR-126 encapsulated. Characterization shows miR-126+ ELVs are similar in size and structure to sEVs. Upon administration to cardiac endothelial cells (CECs), ELV uptake is similar to sEVs too. Further, when functionally validated with a CEC tube formation assay, ELVs significantly improve tube formation parameters compared to sEVs. This study shows TFH-ELVs synthesized from sEVs allow for select miRNA loading and can improve in vitro cardiac outcomes.

Highlights

Myocardial infarction (MI) is one of the leading causes of morbidity and mortality worldwide with an estimated 0.8 million events occurring annually in the United States alone [1]
We show engineer an sEV-like vesicle (ELV) can be internalized and have pro-angiogenic potential compared to small extracellular vesicle (sEV) when administered to cardiac endothelial cells (CECs)
ckit+ progenitor cell (CPC) were transferred to fetal bovine serum (FBS)-depleted media and their conditioned media was collected after 24 h. sEVs were isolated from conditioned media using differential ultracentrifugation (Optima XPN-100, Beckman Coulter, Indianapolis, IN, USA)

Summary

Introduction

Myocardial infarction (MI) is one of the leading causes of morbidity and mortality worldwide with an estimated 0.8 million events occurring annually in the United States alone [1]. Ischemia leads to hypoxia which initiates an inflammatory response and activates neovascularization and fibroblast-activated scar formation [2,3,4]. Despite these attempts at local tissue repair, ischemia leads to irreversible myocardial damage, unfavorable cardiac remodeling and eventually results in end-stage cardiac failure. Treatments include prompt reperfusion and revascularization through pharmacological agents, antithrombotic therapies, or mechanical interventions such as angioplasty and stenting [5] Beyond these traditional approaches, cell-based therapies have shown promise, with the scope to induce cardiac repair and recovery when delivered to the injured site [6,7]. Cardiacderived ckit+ progenitor cells (CPCs) were implicated as pro-reparative agents for cardiac recovery with phase II clinical trials completed (NCT02501811) [8,9,10]

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