Delivery of siRNA using cationic rosette nanotubes for gene silencing

Area of Science:

• Biomaterials Science
• Nanotechnology
• Molecular Biology
• Gene Therapy

Background:

• RNA interference (RNAi) and gene silencing offer therapeutic potential for hereditary diseases.
• Effective delivery strategies are crucial for reducing toxicity and increasing silencing efficiency in RNAi.
• Rosette nanotubes (RNTs), self-assembled from guanine-cytosine DNA, are promising biomimetic nanostructures.

Purpose of the Study:

• To investigate the use of bioactive RNTs for small interfering RNA (siRNA) delivery and gene silencing.
• To synthesize and characterize lysine-functionalized RNTs (KnT) for enhanced siRNA complexation and cellular uptake.
• To evaluate the efficiency of KnT RNTs in delivering siRNA and achieving gene silencing in cancer cell lines.

Main Methods:

• Synthesis of fifteen lysine-functionalized twin-G∧C motifs (KnT, n = 1 to 15) using solid-phase peptide synthesis.
• Self-assembly of KnT motifs into cationic RNTs under physiological conditions.
• Assessment of siRNA complexation and intracellular uptake mediated by KnT RNTs in HCT116 and A549 cells.
• Gene expression analysis to quantify the reduction in target stat3 protein expression.

Main Results:

• Cationic RNTs were successfully formed from lysine-functionalized G∧C motifs.
• KnT RNTs demonstrated efficient siRNA complexation, influenced by cationic charge and RNT length.
• Higher charged KnT RNTs facilitated faster siRNA cellular uptake via the endocytic pathway.
• KnT RNTs protected siRNA from serum degradation, leading to significant stat3 protein expression reduction (~70%).

Conclusions:

• Lysine-functionalized rosette nanotubes (KnT RNTs) represent an effective and biomimetic platform for siRNA delivery.
• The cationic nature and self-assembly properties of KnT RNTs enhance siRNA uptake and gene silencing efficiency.
• This approach shows promise for developing safer and more effective gene silencing therapies for hereditary diseases.