Cholesterol-Enriched Exosomes Used to Improve siRNA Delivery

Researchers from the Chinese Academy of Sciences have discovered a novel approach to improve the delivery of short interfering RNA (siRNA) using cholesterol-enriched exosomes, potentially revolutionizing gene therapy for diseases like cancer and genetic disorders. Their study was published in Nature Nanotechnology.

Using a controllable membrane engineering strategy, researchers prepared exosomes with different cholesterol contents such as milk exosomes, ginger exosomes, and tumor cell-derived exosomes. They found that increasing cholesterol content in exosome membranes significantly enhanced their interaction with target cell membranes, promoting entry through fusion rather than endocytosis. This method bypasses lysosomal degradation, a major hurdle in traditional siRNA delivery.

Molecular modeling revealed that cholesterol-rich exosomes have greater membrane deformability, allowing for expanded contact with cell membranes and more efficient siRNA delivery to the cytoplasm. In vitro experiments showed that milk exosomes enriched with 30% cholesterol effectively delivered PLK1 siRNA, outperforming conventional transfection agents in downregulating PLK1 expression and inducing tumor cell apoptosis.

In vivo studies using a mouse colorectal tumor model demonstrated that these cholesterol-enhanced exosomes, when loaded with siPLK1, effectively inhibited tumor growth through both oral and intravenous administration. This suggests their potential as versatile gene therapy vectors.

This research presents a promising strategy for developing safer and more efficient gene therapies by modulating exosome membrane cholesterol content to promote fusion-mediated cargo transfer.