Cytochalasin B Treatment and Osmotic Pressure Enhance the Production of Extracellular Vesicles (EVs) with Improved Drug Loading Capacity.

Ashita Nair,Jiyoon Bu,Seungpyo Hong,Piper A Rawding,Steven C Do,Hangpeng Li

doi:10.3390/nano12010003

Ashita Nair, Jiyoon Bu + Show 4 more

Open Access

https://doi.org/10.3390/nano12010003

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Abstract

Extracellular vesicles (EVs) have been highlighted as novel drug carriers due to their unique structural properties and intrinsic features, including high stability, biocompatibility, and cell-targeting properties. Although many efforts have been made to harness these features to develop a clinically effective EV-based therapeutic system, the clinical translation of EV-based nano-drugs is hindered by their low yield and loading capacity. Herein, we present an engineering strategy that enables upscaled EV production with increased loading capacity through the secretion of EVs from cells via cytochalasin-B (CB) treatment and reduction of EV intravesicular contents through hypo-osmotic stimulation. CB (10 µg/mL) promotes cells to extrude EVs, producing ~three-fold more particles than through natural EV secretion. When CB is induced in hypotonic conditions (223 mOsm/kg), the produced EVs (hypo-CIMVs) exhibit ~68% less intravesicular protein, giving 3.4-fold enhanced drug loading capacity compared to naturally secreted EVs. By loading doxorubicin (DOX) into hypo-CIMVs, we found that hypo-CIMVs efficiently deliver their drug cargos to their target and induce up to ~1.5-fold more cell death than the free DOX. Thus, our EV engineering offers the potential for leveraging EVs as an effective drug delivery vehicle for cancer treatment.

Highlights

Extracellular vesicles (EVs) are naturally occurring, cell-secreted nanoparticles composed of a lipid bilayer membrane with embedded transmembrane proteins which encloses a cytoplasm that contains biological information of parental cells [1,2,3,4,5]
We assessed the protein-to-particle ratio of EVs obtained from ACHN cells at various incubation conditions: naïve EVs, hypo-EVs (EVs secreted from the cells under hypotonic conditions), CB-induced membrane vesicles (CIMVs) (EVs released from the cells via CB treatment), and hypo-CIMVs (EVs released from the cells via CB treatment at the hypotonic conditions)
Low yield and drug loading capacity limited the clinical translation of EV-based drug delivery systems

Summary

Introduction

Extracellular vesicles (EVs) are naturally occurring, cell-secreted nanoparticles composed of a lipid bilayer membrane with embedded transmembrane proteins (i.e., cell surface receptors) which encloses a cytoplasm that contains biological information of parental cells (i.e., proteins, DNA, and RNA) [1,2,3,4,5]. Many efforts have been made to take advantage of the intrinsic messaging abilities of EVs and utilize them as drug delivery carriers. Unlike synthetic nanoparticles, this natural drug carrier is stable under various physiological and pathological conditions and has a less immunogenic and cytotoxic profile [6]. This natural drug carrier is stable under various physiological and pathological conditions and has a less immunogenic and cytotoxic profile [6] Owing to their unique properties, EVs have been leveraged to deliver RNA [7], enzymes [8], and various chemotherapeutics [9,10].

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