Extracellular vesicles induce minimal hepatotoxicity and immunogenicity

Area of Science:

• Biotechnology
• Nanomedicine
• Cell Biology

Background:

• Extracellular vesicles (EVs) are key mediators of cellular communication.
• Their potential as therapeutic drug delivery vehicles is under investigation.
• Understanding the safety and toxicity of EVs is crucial for drug delivery applications.

Purpose of the Study:

• To evaluate the intrinsic safety and toxicity of Expi293F-derived EVs.
• To assess EV effects on liver cells (HepG2) and in vivo (BALB/c mice).

Main Methods:

• EV uptake confirmed in HepG2 cells.
• In vitro toxicity assays: cell viability, albumin secretion, membrane integrity, mitochondrial/lysosomal activity.
• Whole genome transcriptome analysis of HepG2 cells post-EV exposure.
• In vivo studies in mice: histopathology, liver transaminases, cytokine analysis.

Main Results:

• No hepatotoxicity observed in HepG2 cells even at high EV concentrations (5 × 10^10 EVs/mL).
• Transcriptome analysis showed minimal gene expression changes (<0.6% genes, <2-fold change), with no impact on inflammation or toxicity-related genes.
• No significant pro-inflammatory cytokine response in HepG2 cells; minor changes in IL-8, IL-6, MCP-1 in human blood.
• In vivo administration to mice showed no histopathological changes or significant increases in liver enzymes or cytokines (except modest KC increase).

Conclusions:

• Expi293F-derived EVs exhibit a favorable safety profile.
• The absence of significant in vitro and in vivo toxicity supports their use in therapeutic applications and drug delivery.
• EVs represent a promising platform for developing novel drug delivery systems.