Development and Characterization of Modified Chitosan Lipopolyplex for an Effective siRNA Delivery

Area of Science:

• Biomaterials Science
• Nanotechnology
• Gene Delivery

Background:

• RNA interference (RNAi) therapeutics face challenges like cytotoxicity, rapid degradation, and poor cellular uptake.
• Chitosan (Cs) is a biocompatible and biodegradable polymer, suitable for siRNA delivery.
• Modifying chitosan with arginine enhances its siRNA encapsulation and cellular absorption capabilities.

Purpose of the Study:

• To develop and characterize chitosan-arginine (CsAr) complexes for improved siRNA delivery.
• To encapsulate CsAr-siRNA complexes within anionic liposomes, creating lipopolyplexes (LCAr).
• To evaluate the efficacy, stability, and safety of LCAr for gene transport.

Main Methods:

• Chitosan was modified with arginine to create CsAr complexes.
• Fourier-transform infrared spectroscopy (FTIR) and 13C NMR were used for characterization.
• CsAr-siRNA complexes were encapsulated in DPPC/cholesterol liposomes to form LCAr.
• Agarose gel electrophoresis assessed complex formation, stability, and siRNA encapsulation efficiency.
• Cellular uptake and hemolytic potential were compared to parent polyplexes and Lipofectamine 2000.

Main Results:

• Lipid mass ratio of 10 resulted in complete lipidation of CsAr-siRNA polyplexes, forming LCAr (120-230nm).
• siRNA encapsulation increased from ~70% in polyplexes to ~95% in LCAr.
• LCAr exhibited approximately 4 times lower hemolytic potential than parent polyplexes.
• LCAr demonstrated enhanced cellular association compared to Lipofectamine 2000.

Conclusions:

• Chitosan-arginine conjugation with liposomes provides a simple, safe, and robust carrier for gene delivery.
• LCAr effectively enhances siRNA encapsulation and cellular uptake for gene transport.
• This novel lipopolyplex system offers a promising alternative for siRNA delivery in physiological conditions.