Enzymatically Synthesized DNA Polymer as Co-carrier for Enhanced RNA Interference

Area of Science:

• Biochemistry
• Materials Science
• Nanotechnology

Background:

• Polymerization of small interfering RNA (siRNA) improves delivery by enhancing electrostatic interactions with cationic polymers.
• Current methods require chemical processes and lack optimal nanocomplex formation for polymerized siRNAs.

Purpose of the Study:

• To develop a non-chemical strategy for siRNA polymerization using rolling circle amplification (RCA) DNA.
• To enhance the nanocomplex-forming ability and RNA interference (RNAi) efficiency of polymerized siRNAs.

Main Methods:

• Utilized the strong interaction between RCA DNA product and linear poly(ether imide) (PEI) for stable nanocomplex formation.
• Leveraged the programmable nature of DNA to optimize hybridization efficiency between RCA and sticky siRNAs.
• Employed RCA DNA as a cocarrier to organize siRNA polymerization and reduce PEI usage.

Main Results:

• Achieved stable nanocomplex formation at the charge neutralization point due to high molecular weight RCA DNA (>3,000,000 Da).
• Demonstrated superior siRNA polymerization efficiency through programmable DNA sequencing and optimized hybridization.
• Significantly improved in vitro and in vivo RNAi efficiency of PEI/RCA-siRNA polyplexes.

Conclusions:

• RCA DNA serves as a promising cocarrier material for siRNA polymerization, eliminating chemical processes.
• The developed method enhances RNAi efficiency, offering a potential advancement for RNAi-based therapeutics.
• Strong DNA-polymer interactions and programmable DNA sequences are key to efficient siRNA delivery systems.