Tunable Lipid Coatings Enable Cytoplasmic siRNA Delivery by DNA Origami

Area of Science:

• Biotechnology
• Nanotechnology
• Molecular Biology

Background:

• DNA origami nanostructures (DONs) offer precise control for small RNA delivery.
• DONs face challenges including nuclease degradation, poor cellular uptake, and inefficient endosomal escape.

Purpose of the Study:

• To enhance the performance of DONs for small RNA delivery.
• To develop a strategy for improving cellular uptake and endosomal escape of DONs.

Main Methods:

• Developed an electrostatic lipid-coating strategy for DONs using zwitterionic and cationic lipids.
• Identified an optimal formulation window for colloidally stable, monodisperse lipid-coated DONs (LCDs).
• Evaluated LCDs' cellular uptake, endosomal escape, and siRNA delivery efficiency compared to PEG-coated DONs.

Main Results:

• Lipid-coated DONs (LCDs) demonstrated improved cellular internalization and reduced early endosomal retention.
• A 50 mol % cationic lipid formulation showed the most effective cellular uptake.
• LCDs achieved efficient siRNA silencing comparable to benchmark lipid nanoparticles.

Conclusions:

• Electrostatic lipid coating enhances DONs' potential for cytoplasmic delivery of small RNAs.
• The strategy preserves DON structural integrity and design flexibility.
• Optimized LCDs represent a promising platform for advanced gene therapy applications.