Deciphering the internalization mechanism of WRAP:siRNA nanoparticles

Area of Science:

• Biotechnology
• Molecular Biology
• Nanomedicine

Background:

• Gene silencing via small interfering RNA (siRNA) is a promising therapeutic strategy.
• Peptide-based nanoparticles (PBNs) offer an alternative delivery system for nucleic acids.
• Amphipathic cell-penetrating peptides (CPPs) named WRAP enable efficient siRNA delivery at low doses.

Purpose of the Study:

• To elucidate the cellular uptake mechanisms of WRAP:siRNA nanoparticles.
• To investigate the role of direct translocation versus endocytosis in nanoparticle internalization.

Main Methods:

• Combines biophysical, biological, confocal, and electron microscopy.
• Utilizes chemical inhibitors of endosomal pathways and dynamin triple-knockout cells.
• Includes leakage studies on lipid vesicles and co-localization with transferrin.

Main Results:

• WRAP:siRNA nanoparticles show activity despite endosomal pathway inhibitors, suggesting direct translocation.
• Lipid vesicle leakage studies and dynamin-KO cell experiments support membrane destabilization and direct entry.
• Evidence of endocytosis includes co-localization with transferrin and inhibition by scavenger receptor A inhibitor.

Conclusions:

• WRAP:siRNA nanoparticle efficiency relies on multiple internalization pathways.
• Both direct cell membrane translocation and endocytosis-dependent mechanisms contribute to cellular uptake.
• This dual mechanism enhances the therapeutic potential of WRAP:siRNA nanoparticles.