Higher Order Architecture of Designer Peptides Forms Bioinspired 10 nm siRNA Delivery System

Area of Science:

• Biomaterials Science
• Nanotechnology
• Molecular Biology

Background:

• Biological systems, such as viruses, utilize higher-order architecture for effective nucleic acid transport.
• Previous attempts to replicate these systems using synthetic or natural polymers yielded mixed results.
• There is a need for efficient and safe delivery vehicles for nucleic acid-based therapies.

Purpose of the Study:

• To design and characterize a novel peptide/siRNA quaternary complex for siRNA delivery.
• To create a synthetic system inspired by viral capsids for enhanced nucleic acid transport.
• To evaluate the complex's efficacy in cellular uptake, siRNA release, and gene silencing.

Main Methods:

• Rational design of a peptide assembly using collagen peptide (COL) for stability and cell-penetrating peptide (CPP) for barrier penetration.
• Formation of stoichiometric, 10 nm nanoparticles through hybridization of peptide components with siRNA.
• Assessment of cellular uptake kinetics, siRNA release, gene silencing efficiency, nuclease resistance, and cytotoxicity.

Main Results:

• The peptide/siRNA quaternary complex self-assembled into 10 nm nanoparticles.
• Demonstrated rapid cellular uptake (<30 min) and effective siRNA release.
• Achieved significant gene silencing with protection against nucleases, while exhibiting no immunostimulatory or cytotoxic effects.

Conclusions:

• Synthetic quaternary structures with higher-order architecture can serve as effective delivery vehicles for nucleic acid cargo.
• The developed peptide/siRNA complex represents a promising platform for advancing RNA interference therapeutics.
• This approach offers a nuclease-resistant, non-immunostimulatory, and non-cytotoxic alternative for nucleic acid delivery.