siRNA-aptamer chimeras on nanoparticles: preserving targeting functionality for effective gene silencing

Area of Science:

• Biotechnology
• Nanomedicine
• Molecular Biology

Background:

• siRNA-aptamer chimeras offer cell-type specific siRNA delivery.
• Challenges include endosomal escape and maintaining aptamer specificity in delivery systems.

Purpose of the Study:

• To develop a nanoparticle vector for efficient siRNA-aptamer chimera delivery.
• To enhance targeted RNA interference (RNAi) and endosomal escape.

Main Methods:

• Designed a nanoparticle vector with high siRNA payload capacity and exposed aptamers.
• Employed a two-step grafting process for siRNA-aptamer chimeras to retain conformation and accessibility.
• Incorporated a proton sponge effect for endosomal escape and fluorescence for imaging.

Main Results:

• The novel nanoparticle vector demonstrated selective gene silencing, achieving 34% more silenced cells compared to non-targeted complexes.
• This improved efficiency is attributed to preserved aptamer conformation and enhanced cell uptake.
• Conventional one-step adsorption showed only marginal improvement in RNAi effect.

Conclusions:

• The rationally designed nanoparticle vector significantly enhances the efficiency of siRNA-aptamer chimeras for targeted RNAi.
• The two-step grafting method is crucial for maintaining aptamer integrity and function.
• This approach overcomes key challenges in siRNA delivery, paving the way for advanced therapeutic applications.