Polymeric nanoparticles for siRNA delivery and gene silencing

Area of Science:

• Biotechnology
• Nanomedicine
• Molecular Biology

Background:

• Gene silencing using small interfering RNA (siRNA) holds significant therapeutic promise.
• Effective delivery of siRNA is crucial for its therapeutic applications.
• Biodegradable polymers like PLGA are explored for nanoparticle-based drug delivery systems.

Purpose of the Study:

• To investigate poly(d,l-lactide-co-glycolide) (PLGA) nanoparticles formulated with polyethylenimine (PEI) for enhanced siRNA delivery.
• To evaluate the encapsulation efficiency, in vitro release, and gene silencing efficacy of PLGA-PEI nanoparticles.
• To assess the cellular uptake, intracellular delivery, serum stability, and cytotoxicity of the developed nanoparticles.

Main Methods:

• PLGA-PEI nanoparticles were formulated using the double emulsion-solvent evaporation technique.
• siRNA encapsulation, in vitro release kinetics, and gene silencing of a model gene (fire-fly luciferase) were evaluated.
• Cellular uptake was quantified, and intracellular siRNA delivery was visualized using fluorescence microscopy.

Main Results:

• Incorporation of PEI into PLGA nanoparticles significantly increased siRNA encapsulation (approx. 2-fold) and improved the release profile.
• PLGA-PEI nanoparticles effectively silenced luciferase gene expression in cells with stable or inducible overexpression.
• Quantitative and fluorescence microscopy studies revealed a 2-fold higher cellular uptake and efficient cytosolic delivery of siRNA by PLGA-PEI nanoparticles.

Conclusions:

• PLGA-PEI nanoparticles demonstrate enhanced siRNA encapsulation, improved cellular uptake, and effective gene silencing, indicating their potential for therapeutic applications.
• The developed nanoparticles exhibit favorable characteristics, including serum stability and lack of cytotoxicity.
• PLGA-PEI nanoparticles represent a promising platform for siRNA-based gene silencing therapies.