The Antiangiogenic Effect of VEGF-A siRNA-FAM-Loaded Exosomes

Area of Science:

• Ophthalmology
• Molecular Biology
• Biotechnology

Background:

• Neovascular ocular diseases stem from vascular endothelial growth factor A (VEGFA) overexpression.
• Current anti-VEGF therapies face challenges with stability and delivery efficiency.
• Exosomes offer enhanced in vivo stability and intracellular delivery for therapeutic applications.

Purpose of the Study:

• To develop and evaluate an exosome-based delivery system for vascular endothelial growth factor A siRNA (siRNA).
• To assess the efficacy of exosome-encapsulated siRNA in inhibiting VEGFA expression and angiogenesis in vitro.
• To investigate the potential of this technology for treating neovascular eye diseases.

Main Methods:

• Exosomes were purified and concentrated using chromatography.
• Fluorescein amidite (FAM)-labeled VEGFA siRNA was loaded into exosomes.
• In vitro studies assessed siRNA delivery, VEGFA inhibition, apoptosis induction (Annexin V-FITC/PI-PE staining via FACS), and angiogenesis inhibition in human umbilical vascular endothelial cells (HUVECs).

Main Results:

• Successful delivery of hVEGFA siRNA-FAM into target cells was confirmed, with high efficacy observed at 48 hours.
• VEGFA expression was significantly inhibited, and apoptosis was markedly increased in cells treated with hVEGFA siRNA-FAM-loaded exosomes in a time-dependent manner.
• Exosome-mediated siRNA delivery significantly weakened angiogenesis in HUVECs, with complete inhibition by 72 hours, attributed to reduced VEGFA, PIGF, and VEGFC levels.

Conclusions:

• Exosome-encapsulated FAM-tagged VEGFA siRNA demonstrates effective delivery and therapeutic potential.
• This approach successfully induces apoptosis and inhibits angiogenesis in vitro by reducing key growth factor levels.
• The findings support the development of exosome-based siRNA delivery for treating ocular neovascularization and related diseases.